Sunday, November 11, 2018

Install MySQL 5.7, Apache 2.4, PHP 7.1 on Ubuntu 16.04

Install MySQL 5.7, Apache 2.4, PHP 7.1 on Ubuntu 16.04

Install VMware tools:

VM > Guest > Install/Upgrade VMware Tools

# su -
# df -h
# cd /media/jun/VMware\ Tools/
# ls -la
# tar zxvf VMwareTools-9.4.0-1280544.tar.gz -C /tmp/
# cd /tmp
# ls
# cd vmware-tools-distrib/
# ls
# ./vmware-install.pl -d
# reboot

Note: For more info https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1022525

Move Ubuntu launcher to the bottom:

# gsettings set com.canonical.Unity.Launcher launcher-position Bottom

Update the package repository:

# apt-get update

Upgrades packages with auto-handling of dependencies:

# apt-get dist-upgrade

or

# apt full-upgrade

Install SSH server:

# apt-get install openssh-server
# systemctl status sshd.service
# systemctl restart sshd.service

Compile and install the latest Git 2.19.0 from source code:

# apt-get install dh-autoreconf libcurl4-gnutls-dev libexpat1-dev gettext libz-dev libssl-dev \
&& apt-get install curl \
&& cd /usr/local/src/ \
&& curl -L https://github.com/git/git/archive/v2.19.0.tar.gz -o git.tar.gz \
&& tar zxvf git.tar.gz \
&& cd git-2.19.0/ \
&& make configure \
&& ./configure --prefix=/usr \
&& make all \
&& make install

# git --version

git version 2.19.0

Install Git from ppa:

# add-apt-repository ppa:git-core/ppa
# apt-get update

# apt-cache policy git
# apt-cache madison git

# apt-get install git=1:2.11.0-2~ppa0~ubuntu16.04.1

# git --version

Compile and install the latest Vim 8:

# apt-get install libncurses5-dev python-dev ruby-dev libperl-dev ruby-dev liblua5.3-dev exuberant-ctags cscope

// Fix liblua paths
# ln -s /usr/include/lua5.3 /usr/include/lua \
&& ln -s /usr/lib/x86_64-linux-gnu/liblua5.3.so /usr/local/lib/liblua.so

# cd /usr/local/src \
&& git clone https://github.com/vim/vim.git --depth 1 \
&& cd vim \
&& ./configure \
--prefix=/usr --with-features=huge --enable-multibyte --enable-pythoninterp \
--enable-rubyinterp --enable-perlinterp --enable-luainterp --enable-cscope \
&& make \
&& make install

# hash -r
# vim --version | head

Install MTA mail server:

# apt-get install postfix

Note: select "Internet site".

Note: If you need to reconfigure the postfix setting, run either one of the following:

# dpkg-reconfigure -plow postfix

or

# apt-get purge postfix

For other mail related packages:

# apt-get install mailutils

Install mail client:

# apt-get install bsd-mailx
# echo "test message" | mailx -s 'test subject' myemail@mydomain.com

For hexdump command:

# apt-get install bsdmainutils

# hexdump -c test.log

Install MySQL5.7:

# apt-cache policy mysql-server
# apt-cache search mysql-server
# apt-cache show mysql-server | less
# apt show mysql-server

# apt-get install mysql-server

# vim /etc/mysql/mysql.conf.d/mysqld.cnf
bind-address = 0.0.0.0

# vim ~/.my.cnf
[client]
host = localhost
port = 3306
user = root
password = MyPassword

# chmod 400 ~/.my.cnf

# mysql -e "SHOW variables WHERE variable_name REGEXP 'open_files_limit|table_open_cache|max_connections';"
+----------------------------+-------+
| Variable_name              | Value |
+----------------------------+-------+
| max_connections            | 151   |
| open_files_limit           | 1024  |
| table_open_cache           | 431   |
| table_open_cache_instances | 16    |
+----------------------------+-------+

Note: You will see the following error message in the error.log file if you did not change the open files limit:
[Warning] Changed limits: max_open_files: 1024 (requested 5000)
[Warning] Changed limits: table_open_cache: 431 (requested 2000)

# mkdir /etc/systemd/system/mysql.service.d
# vim /etc/systemd/system/mysql.service.d/override.conf

[Service]
#LimitNOFILE=infinity
LimitNOFILE=5000

#LimitMEMLOCK=infinity

# systemctl daemon-reload
# systemctl restart mysql

# mysql -e "SHOW variables WHERE variable_name REGEXP 'open_files_limit|table_open_cache|max_connections';"
+----------------------------+-------+
| Variable_name              | Value |
+----------------------------+-------+
| max_connections            | 151   |
| open_files_limit           | 5000  |
| table_open_cache           | 2000  |
| table_open_cache_instances | 16    |
+----------------------------+-------+

To check MySQL process's limit:

# cat /proc/$(pgrep mysqld$)/limits
Limit                     Soft Limit           Hard Limit           Units
Max cpu time              unlimited            unlimited            seconds
Max file size             unlimited            unlimited            bytes
Max data size             unlimited            unlimited            bytes
Max stack size            8388608              unlimited            bytes
Max core file size        0                    unlimited            bytes
Max resident set          unlimited            unlimited            bytes
Max processes             15614                15614                processes
Max open files            5000                 5000                 files
Max locked memory         65536                65536                bytes
Max address space         unlimited            unlimited            bytes
Max file locks            unlimited            unlimited            locks
Max pending signals       15614                15614                signals
Max msgqueue size         819200               819200               bytes
Max nice priority         0                    0
Max realtime priority     0                    0
Max realtime timeout      unlimited            unlimited            us

Note: https://dev.mysql.com/doc/refman/5.7/en/using-systemd.html

Note: https://stackoverflow.com/questions/30901041/can-not-increase-max-open-files-for-mysql-max-connections-in-ubuntu-15

Note: https://serverfault.com/questions/821695/mysqld-service-for-systemd-failed-to-parse-resource-value-ignoring-40000-l

To move a MySQL data directory to another directory:

# mysql -e "SELECT @@datadir;"
+-----------------+
| @@datadir       |
+-----------------+
| /var/lib/mysql/ |
+-----------------+

# systemctl stop mysql
# systemctl status mysql

# vim /etc/mysql/mysql.conf.d/mysqld.cnf
datadir         = /home/mysql

# vim /etc/apparmor.d/tunables/alias
alias /var/lib/mysql/ -> /home/mysql/,

Note: We need to tell AppArmor to let MySQL write to the new directory by creating an alias between the default directory and the new location.

Note: If you skipped the AppArmor configuration step, you would see the following error message:

Job for mysql.service failed because the control process 
exited with error code. See "systemctl status mysql.service" 
and "journalctl -xe" for details.

# systemctl restart apparmor
# systemctl restart mysql

To move the existing to MySQL directory to /home:

# rsync -av /var/lib/mysql /home

Or, you can run the following commands to initialize the MySQL data directory:

# mkdir /home/mysql \
&& chown mysql:mysql /home/mysql \
&& chmod 700 /home/mysql \
&& mysqld --initialize-insecure

Note: This option is used to initialize a MySQL installation by creating the data directory and populating the tables in the mysql system database.

Note: If you use --initialize, the random initial password is stored at: tail -n 1 /var/log/mysql/error.log.

Note: You can also start mysqld with --skip-grant-tables to access the database and change the password.

# systemctl start mysql && systemctl status mysql

Login MySQL with the above commands if you initialized MySQL data directory with --initialize-insecure option.
# mysql -u root --skip-password
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'new_password';

Check the current MySQL data directory:

# mysql -e "SELECT @@datadir;"
+--------------+
| @@datadir    |
+--------------+
| /home/mysql/ |
+--------------+

To change the root password if you did not know the current root password:

# vim /root/tmp/mysql-init.txt
GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY 'YourPassWordHere' WITH GRANT OPTION;
GRANT SUPER ON *.* TO 'root'@'localhost';
FLUSH PRIVILEGES;

# mysqld --init-file=/root/tmp/mysql-init.txt

Use RAM-DISK for tmpdir:

# mysql -e "SHOW GLOBAL STATUS LIKE 'Created_tmp%tables';"
# mysql -e "SHOW GLOBAL VARIABLES LIKE '%table_size';"

# mkdir -p /mnt/ramdisk
# mount -t tmpfs -o size=512M tmpfs /mnt/ramdisk
# chown mysql:mysql /mnt/ramdisk

# id mysql

uid=123(mysql) gid=130(mysql) groups=130(mysql)

# vim /etc/fstab

tmpfs           /mnt/ramdisk     tmpfs   rw,uid=123,gid=130,mode=1770,size=512M    0       0

Note: You need to change the uid and gid of MySQL.

# mysql -e "SHOW GLOBAL VARIABLES LIKE 'tmpdir';"

# vim /etc/apparmor.d/local/usr.sbin.mysqld

/mnt/ramdisk rw,
owner /mnt/ramdisk/** rwkl,

Note: The first line gives read and write access to the directory, the second line gives read, write, lock(k) and link(l) access to all the files and the directories inside the directory owned by the mysql user.

# vim /etc/mysql/mysql.conf.d/mysqld.cnf

[mysqld]
tmpdir      = /mnt/ramdisk

# systemctl restart apparmor.service
# systemctl restart mysql.service

Install PHP7.1:

# command -v add-apt-repository >/dev/null 2>&1 \
|| { echo >&2 "add-apt-repository is not installed. I will install it for you"; apt-get install python-software-properties; }

# add-apt-repository -y ppa:ondrej/php
# apt-get update

# apt-cache policy php7.1

# apt-get install php7.1-fpm
# apt-get install php7.1-xml php7.1-curl php7.1-zip php7.1-gd php7.1-bcmath php7.1-intl php7.1-mbstring php7.1-mcrypt php7.1-mysql
# apt-get install php7.1-json php7.1-opcache
# apt-get install php-xdebug

# php -v
PHP 7.1.10-1+ubuntu16.04.1+deb.sury.org+1 (cli) (built: Sep 29 2017 17:04:25) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies
    with Zend OPcache v7.1.10-1+ubuntu16.04.1+deb.sury.org+1, Copyright (c) 1999-2017, by Zend Technologies
    with Xdebug v2.5.5, Copyright (c) 2002-2017, by Derick Rethans

# vim /etc/php/7.1/fpm/pool.d/www.conf

;listen = /run/php/php7.1-fpm.sock
listen = 127.0.0.1:9000

Note: You can choose to use either a Unix socket (for local access only) or TCP socket (for the other server on the network to access).

# systemctl restart php7.1-fpm.service && systemctl status php7.1-fpm.service

# ss -an | grep :9000
tcp    LISTEN     0      128    127.0.0.1:9000                  *:*

# vim /etc/php/7.1/fpm/php.ini

date.timezone = America/Vancouver
display_errors = On
display_startup_errors = On
error_reporting = E_ALL
error_log = /var/log/php_errors.log

List all the installed PHP packages:

# dpkg -l | grep php| awk '{print $2}' |tr "\n" " "

Show the available package version:

# apt-cache search php
# apt-cache policy php

Install the specific package version:

# apt-get install php7=7.0+35ubuntu6

Note: You can look up old versions of packages at their site http://www.debian.org/distrib/packages

Install older version of PHP (PHP5.6):

# add-apt-repository ppa:ondrej/php

# apt-get update

# apt-get install php5.6-fpm

# apt-get install php5.6-gd php5.6-intl php5.6-json php5.6-mbstring php5.6-mcrypt php5.6-mysql php5.6-opcache php5.6-xml

# a2disconf php7.0-fpm.conf
# a2enconf php5.6-fpm.conf

# systemctl restart apache2.service

Install Apache2.4:

# command -v add-apt-repository >/dev/null 2>&1 \
|| { echo >&2 "add-apt-repository is not installed. I will install it for you"; apt-get install python-software-properties; }

# add-apt-repository -y ppa:ondrej/apache2
# apt-get update

# apt-cache policy apache2

# apt-get install apache2

Enable the following modules to talk to PHP:

# cat /etc/apache2/conf-available/php7.1-fpm.conf

# a2enmod proxy proxy_fcgi rewrite setenvif ssl
# a2enconf php7.1-fpm.conf

If your apache is talking to PHP through a TCP socket (127.0.0.1:9000) instead of a Unix socket (/run/php/php7.1-fpm.sock), you will need to modify the following line:

# vim /etc/apache2/conf-available/php7.1-fpm.conf
# Define a matching worker.
    # The part that is matched to the SetHandler is the part that
    # follows the pipe. If you need to distinguish, "localhost; can
    # be anything unique.
    <Proxy "fcgi://localhost/" enablereuse=on max=10>
    </Proxy>
    <FilesMatch ".+\.ph(ar|p|tml)$">
        #SetHandler "proxy:unix:/run/php/php7.1-fpm.sock|fcgi://localhost"
        SetHandler "proxy:fcgi://127.0.0.1:9000"
    </FilesMatch>

# apache2ctl configtest
# systemctl restart apache2 && systemctl status apache2

Install and enable the following Apache modules if you are connecting to PHP through a TCP socket (127.0.0.1:9000):

# apt-get install libapache2-mod-fastcgi
# a2enmod fastcgi rewrite setenvif


Edit apache2.conf:

# vim /etc/apache2/apache2.conf

AllowOverride All

Set up a virtual host:

# cd /etc/apache2/sites-available
# cp 000-default.conf mag2.local.conf
# vim mag2.local

Check the configuration:

# apache2ctl -V
# apache2ctl -t
# apache2ctl -M
# apache2ctl configtest

Enable the site:

# a2ensite mag2.local

Start MySQL, PHP, and Apache:

# systemctl restart mysql.service
# systemctl restart php7.0-fpm.service
# systemctl restart apache2.service

# ps auxww | grep -i mysql
# ps auxww | grep -i php-fpm
# ps auxww | grep -i apache2

Install PHPStorm:

# cd ~jun/Downloads/
# tar xf PhpStorm-*.tar.gz -C /opt/
# cd /opt/PhpStorm-163.10504.2/
# ./bin/phpstorm.sh

Generate a self-signed SSL certificate:

# openssl req -x509 -nodes -days 365 -newkey rsa:2048 -subj "/C=CA/ST=British Columbia/L=Vancouver/O=My Company Name/CN=erp.local" -keyout /etc/ssl/private/test.local.key -out /etc/ssl/certs/test.local.crt

Install node:

$ curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash

$ command -v nvm

nvm

$ nvm ls-remote
$ nvm install 8.9.3
$ nvm use 8.9.3
$ node -v
$ nvm ls

$ echo '{}' > package.json
$ npm install webpack eslint js-beautify --save-dev

Reference:

https://wiki.apache.org/httpd/PHP-FPM

http://httpd.apache.org/docs/2.4/mod/mod_proxy_fcgi.html

https://www.digitalocean.com/community/tutorials/how-to-move-a-mysql-data-directory-to-a-new-location-on-ubuntu-16-04

http://www.fromdual.com/mysql-tmpdir-on-ram-disk

http://www.victordodon.com/changing-mysql-tmpdir-in-ubuntu/

https://blog.remirepo.net/post/2014/03/28/PHP-FPM-and-HTTPD-2.4-improvement

Monday, October 29, 2018

Running php-fpm in Docker based on CentOS 7

Running php-fpm in Docker based on CentOS 7

Dockerfile:

FROM centos:centos7

RUN curl 'https://setup.ius.io/' -o setup-ius.sh \
 && bash setup-ius.sh \
 && rm -f setup-ius.sh \
 && yum -y update \
 && yum -y install \
  php71u-common \
  php71u-cli \
  php71u-fpm \
  php71u-opcache \
  php71u-xml \
  php71u-json \
  php71u-pdo \
  php71u-mysqlnd \
  php71u-intl \
  php71u-mbstring \
  php71u-mcrypt \
  php71u-gd \
  php71u-soap \
  php71u-process \
  php71u-pecl-redis \
  php71u-pecl-xdebug \
  php71u-fpm-httpd

EXPOSE 9000

CMD ["php-fpm", "-F"]

Build the docker image:

# docker build -t junhsieh/php7.1-fpm:0.0.0 .

Some important settings to be changed:

# vim /etc/php-fpm.d/www.conf

; Change ownership:

user = php-fpm
group = php-fpm

; Note: Ubuntu uses www-data user. Add php-fpm user to www-data group if the other container used it.
; # groupadd -g 33 www-data
; # useradd www-data -m -c 'web user' -u 33 -g 33
; # usermod -a -G www-data php-fpm
; # id php-fpm
; Now, restart this container to ensure php-fpm user is in www-data group.

; Bind port 9000 to the all interfaces:

listen = 9000
;listen = [::]:9000

; Note: PHP-FPM has a listen.client_allowed setting which allows you to set a list of IPs that can connect, or leave blank for any IP to connect. However, even with it being left blank, the issue still persisted. Digging into the official PHP-FPM repo, I discovered that you also need to set  listen = [::]:9000 which then began to allow any IP to connect.
; Note: https://stackoverflow.com/questions/19806945/docker-and-connections-between-containers

; Comment out the following line:

;listen.allowed_clients = 127.0.0.1

; Note: "listen.allowed_clients = any" will not work.
; Note: "listen.allowed_clients = other-container-name" will not work. IP address only.


; Uncomment the following line to debug the issue:

catch_workers_output = yes

; Note: Comment it out on production.


xdebug setting:

### xdebug setting
###
; Enable xdebug extension module
zend_extension=xdebug.so
;zend_extension=/usr/lib64/php/modules/xdebug.so

xdebug.default_enable=1
xdebug.remote_enable=1
xdebug.remote_handler=dbgp
xdebug.remote_host=localhost
xdebug.remote_port=9009
; Note: php-fpm uses port 9000 as well.
xdebug.remote_log=/tmp/xdebug.log
xdebug.remote_connect_back=0
xdebug.remote_autostart=0
xdebug.remote_mode=req

xdebug.max_nesting_level=1000

Reference:

https://developers.redhat.com/blog/2014/12/29/running-php-fpm-in-docker/

Sunday, October 14, 2018

usermod and groupmod not found in Alpine Linux Docker Image

usermod and groupmod not found in Alpine Linux Docker Image

$ vim Dockerfile

FROM alpine:latest

RUN apk --no-cache add shadow \
  && usermod -u 2500 elasticsearch \
  && groupmod -g 2500 elasticsearch

Monday, October 8, 2018

Setup A Centralized Log Server Using Rsyslog on Ubuntu 16.04 LTS

Setup A Centralized Log Server Using Rsyslog on Ubuntu 16.04 LTS

Rsyslog Server:

# vim /etc/rsyslog.conf

# provides UDP syslog reception
module(load="imudp")
input(type="imudp" port="514")

# provides TCP syslog reception
module(load="imtcp")
input(type="imtcp" port="514")

# vim /etc/rsyslog.d/tmpl.conf

$template TmplAuth, "/var/log/client_logs/%HOSTNAME%/%PROGRAMNAME%.log"
$template TmplMsg, "/var/log/client_logs/%HOSTNAME%/%PROGRAMNAME%.log"

authpriv.* ?TmplAuth
*.info;mail.none;authpriv.none;cron.none ?TmplMsg

# systemctl restart rsyslog

Rsyslog Client:

# vim /etc/rsyslog.conf

##RULES## 
*.* @192.168.1.200:514

Note: The @ symbol before the IP address tells rsyslog to use UDP to send the messages. Change this to @@ to use TCP.

# systemctl restart rsyslog

# logger -s " This is my Rsyslog client "

# tree /var/log/client_logs/

The following is a list of RFCs that define the Syslog protocol:

RFC 3195 Reliable Delivery for syslog
RFC 5424 The Syslog Protocol
RFC 5425 TLS Transport Mapping for Syslog
RFC 5426 Transmission of Syslog Messages over UDP
RFC 5427 Textual Conventions for Syslog Management
RFC 5848 Signed Syslog Messages
RFC 6012 Datagram Transport Layer Security (DTLS) Transport Mapping for Syslog

Reference:

http://yallalabs.com/linux/how-to-setup-a-centralized-log-server-using-rsyslog-on-ubuntu-16-04-lts/

https://success.trendmicro.com/solution/TP000086250-What-are-Syslog-Facilities-and-Levels

https://en.wikipedia.org/wiki/Syslog

https://www.elastic.co/blog/how-to-centralize-logs-with-rsyslog-logstash-and-elasticsearch-on-ubuntu-14-04

https://www.elastic.co/guide/en/beats/filebeat/master/filebeat-input-syslog.html

Caused by: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative names matching IP address XXXXX found

Caused by: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative names matching IP address XXXXX found 
at sun.security.ssl.Alerts.getSSLException(Unknown Source) ~[na:1.8.0_51] 
at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source) ~[na:1.8.0_51] 

# vim LDAPConnTest.java

Hashtable<String, Object> objEnvironment;
    objEnvironment = new Hashtable<String, Object>(11);
    objEnvironment.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
    objEnvironment.put(Context.PROVIDER_URL,  "LDAPS://domain:636");
    objEnvironment.put(Context.SECURITY_AUTHENTICATION, "simple");
    objEnvironment.put(Context.SECURITY_PRINCIPAL, <username>);
    objEnvironment.put(Context.SECURITY_CREDENTIALS, <Password>);
    objEnvironment.put("java.naming.ldap.attributes.binary", <attributes>);
    System.setProperty("javax.net.ssl.trustStore", "certificates".concat(File.separator).concat("cacerts"));
    this.objLDAPContext = new InitialLdapContext(objEnvironment, null);

# java main -Dcom.sun.jndi.ldap.object.disableEndpointIdentification=true

Note: Do not use the -Dcom.sun.jndi.ldap.object.disableEndpointIdentification=true option on production server.

Improve LDAP support Endpoint identification has been enabled on LDAPS connections.

To improve the robustness of LDAPS (secure LDAP over TLS ) connections, endpoint identification algorithms have been enabled by default.

Note that there may be situations where some applications that were previously able to successfully connect to an LDAPS server may no longer be able to do so. Such applications may, if they deem appropriate, disable endpoint identification using a new system property: com.sun.jndi.ldap.object.disableEndpointIdentification.

Define this system property (or set it to true) to disable endpoint identification algorithms.

Reference:

https://stackoverflow.com/questions/51622117/issue-with-dns-naming-and-certificates-ldap-context

https://www.oracle.com/technetwork/java/javase/8u181-relnotes-4479407.html

fail to run in alpine docker with error "no such file or directory"

fail to run in alpine docker with error "no such file or directory"

Edit main.go:

# vim main.go

package main

import (
        "fmt"
        "log"
        "net/http"
)

func handler(w http.ResponseWriter, r *http.Request) {
        fmt.Printf("Hello World\n")
        fmt.Fprintf(w, "Hi there, I love %s!", r.URL.Path[1:])
}

func main() {
        http.HandleFunc("/", handler)
        log.Fatal(http.ListenAndServe(":8080", nil))
}

Build main.go:

# CGO_ENABLED=0 go build main.go

Note: Static build: GOOS=linux GOARCH=amd64 go build main.go

Dockerfile:

#
FROM alpine:latest
RUN apk --no-cache add ca-certificates

COPY main /usr/local/bin

CMD /usr/local/bin/main

Build Docker image:

# docker build -t exp/main:0.0.0 .

CentOS and Red Hat 7: Install Linux, Apache MPM, MariaDB, PHP (LAMP) Stack

CentOS and Red Hat 7: Install Linux, Apache MPM, MariaDB, PHP (LAMP) Stack

Quick Start

Install IUS repository, utilities, Git, Go, php-cs-fixer:

# curl 'https://setup.ius.io/' -o setup-ius.sh \
&& bash setup-ius.sh \
&& rm -f setup-ius.sh \
&& yum -y update \
&& yum -y install ntp wget epel-release tmux tree git2u \
&& rm -rf /usr/local/go \
&& curl -L 'https://dl.google.com/go/go1.10.4.linux-amd64.tar.gz' -o go.tar.gz \
&& tar -zxvf go.tar.gz -C /usr/local \
&& rm -f go.tar.gz \
&& curl -L http://cs.sensiolabs.org/download/php-cs-fixer-v2.phar -o php-cs-fixer \
&& chmod 755 php-cs-fixer \
&& mv php-cs-fixer /usr/local/bin/php-cs-fixer \
&& systemctl enable ntpd.service && systemctl restart ntpd.service

# echo 'export GOPATH="$HOME/go"' >> ~/.bashrc \
&& echo 'export PATH="$PATH:/usr/local/go/bin:$GOPATH/bin:/usr/local/bin"' >> ~/.bashrc \
&& source ~/.bashrc

Install the environmental configuration:

# cd \
&& git clone https://github.com/junxie6/config_centos_v2.git \
&& bash config_centos_v2/script/setHomeConfig.sh \
&& source ~/.bashrc \
&& tmux

Note: git remote set-url origin git@github.com:junxie6/config_centos_v2.git

Install Vim:

# yum -y install gcc make ncurses ncurses-devel \
ruby ruby-devel lua lua-devel luajit \
luajit-devel ctags python python-devel \
python3 python3-devel tcl-devel \
perl perl-devel perl-ExtUtils-ParseXS \
perl-ExtUtils-XSpp perl-ExtUtils-CBuilder \
perl-ExtUtils-Embed \
ctags cscope

# cd /usr/local/src \
&& git clone https://github.com/vim/vim.git --depth 1\
&& cd vim \
&& ./configure --prefix=/usr --with-features=huge --enable-multibyte --enable-rubyinterp --enable-pythoninterp --enable-perlinterp --enable-luainterp --enable-cscope \
&& make \
&& make install \
&& hash -r \
&& vim --version | grep VIM

Install Docker:

# yum -y install yum-utils \
&& yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo \
&& yum makecache fast \
&& yum -y install docker-ce \
&& systemctl enable docker \
&& systemctl start docker \
&& usermod -aG docker jun \
&& docker version

Note: Log out and log back in so that your Docker group membership is re-evaluated.

# ps auxww | grep -i docker

Install docker-compose:

# curl -L https://github.com/docker/compose/releases/download/1.15.0/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose \
&& chmod 755 /usr/local/bin/docker-compose

Enable firewall ports on Docker Manager node:

# firewall-cmd --permanent --zone=public \
--add-port=2377/tcp \
--add-port=7946/tcp \
--add-port=7946/udp \
--add-port=4789/udp \
&& firewall-cmd --reload \
&& systemctl restart docker.service \
&& firewall-cmd --zone=public --list-all

Note: Add TCP port 2376 if you need to use Docker Machine to work. Docker Machine is used to orchestrate Docker hosts.

Enable firewall ports on Docker Worker nodes:

# firewall-cmd --permanent --zone=public \
--add-port=7946/tcp \
--add-port=7946/udp \
--add-port=4789/udp \
&& firewall-cmd --reload \
&& systemctl restart docker.service \
&& firewall-cmd --zone=public --list-all

Note: Add TCP port 2376 if you need to use Docker Machine to work. Docker Machine is used to orchestrate Docker hosts.

Install Apache 2.4:

# yum -y install httpd24u httpd24u-mod_ssl

Install PHP 7.1:

# yum -y install php71u-common php71u-cli php71u-fpm php71u-fpm-httpd php71u-opcache php71u-xml php71u-json php71u-pdo php71u-mysqlnd php71u-intl php71u-mbstring php71u-mcrypt php71u-gd php71u-process

Install sysdig:

# curl -s https://s3.amazonaws.com/download.draios.com/stable/install-sysdig | sudo bash

// the ncurses user interface for sysdig
# csysdig

// the definitive system and process troubleshooting tool
# sysdig

Check CentOS version:

# cat /etc/redhat-release

CentOS Linux release 7.1.1503 (Core)

Set up a static IP address for the network:

# ip addr

2: eno16777736: <broadcast> mtu 1500 qdisc pfifo_fast state UP qlen 1000

# vi /etc/sysconfig/network-scripts/ifcfg-eno16777736

BOOTPROTO=none

IPADDR=192.168.6.9
PREFIX=24
GATEWAY=192.168.6.1
DNS1=8.8.8.8
DNS2=8.8.4.4

PEERDNS=yes
ONBOOT=yes
USERCTL=no

Note: USERCTL=no // Non-root users are not allowed to control this device.

# systemctl restart network

# ip addr

# /bin/ipcalc --netmask 192.168.6.9/24

NETMASK=255.255.255.0

# cat /etc/resolv.conf

Change hostname:

# hostnamectl status

# hostnamectl set-hostname cent-dev.local

# hostnamectl status

# cat /etc/hostname

If you are using Amazon's AWS EC2 instance, append the following string at the bottom of the file to ensure that the hostname is preserved between restarts/reboots:

# vim /etc/cloud/cloud.cfg

preserve_hostname: true

More info: https://aws.amazon.com/premiumsupport/knowledge-center/linux-static-hostname-rhel7-centos7/

Set up timezone:

# timedatectl
# timedatectl list-timezones
# timedatectl set-timezone America/Vancouver
# timedatectl

Set up date and time:

# date +%Y%m%d -s "20081128"
# date +%T -s "10:13:13"

To sync date and time automatically:

# yum -y update

# yum -y install ntp

# ntpdate 0.us.pool.ntp.org

Note: ntpdate is deprecated as of September 2012

You can change which ntp server to use:

# vi /etc/ntp.conf

Set ntpd to start up on boot time:

# systemctl enable ntpd.service
# systemctl restart ntpd.service

# ps auxww|grep -i ntpd
# ntpstat
# timedatectl

Set the Hardware Clock to the current System Time:

# hwclock --systohc

Note: hwclock is a utility for accessing the hardware clock. Hardware clock is independent of the operation system you use and works even when the machine is shut down. This program is used to find out the time from the hardware clock and set the system time at boot time.

Update the ~/.bashrc configuration:

# vi ~/.bashrc

### alias
alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'

alias gs='git status'
alias gc='git commit -a -m "up"'
alias gp='git push'
alias gpp='git pull'

alias ls='ls --color=auto'
alias ll='ls -la'
alias h='history'

### ls with color (try "ls --color=auto").
#export CLICOLOR=1 # Use colors (if possible)
#export LSCOLORS="ExGxFxdxCxDxDxBxBxExEx"

### set up a clean UTF-8 environment
### run: locale command
export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8
export LANGUAGE=en_US.UTF-8

### display history command with date and time
export HISTTIMEFORMAT="%m/%d/%y %T "

### Prompt
PS1='\[\e[0;32m\]\u@\h \w \$\[\e[0m\] '

#######
# Note: on Ubuntu, xterm-256color may be in different place, try this:
# find /lib/terminfo /usr/share/terminfo -name "*256*"
# Note: tmux respects screen-256color
#######
if [ -e /usr/share/terminfo/x/xterm-256color ]; then
  export TERM='xterm-256color'
else
  export TERM='xterm-color'
fi

### Make bash check its window size after a process completes
shopt -s checkwinsize

# Source global definitions
if [ -f /etc/bashrc ]; then
  . /etc/bashrc
fi

# source ~/.bashrc

Update the ~/.inputrc configuration:

# vi ~/.inputrc

### enable filename tab auto-completion
set show-all-if-ambiguous on
set show-all-if-unmodified on

### if you don't want case-sensitivity
#set completion-ignore-case on

### bash history completion to complete what's already on the line
### arrow up
"\e[A": history-search-backward
### arrow down
"\e[B": history-search-forward

Make sure there is a swap space on your system:

# cat /proc/meminfo | grep -i swap

SwapCached:           36 kB
SwapTotal:       2097148 kB
SwapFree:        2095160 kB

Note: if your system does not have the swap space, please refer to http://blog.ijun.org/2015/04/add-swap-to-amazon-ec2-instance-ebs.html for more information.

Install EPEL and additional repositories on CentOS and Red Hat:

# yum -y install wget
# yum -y install epel-release

http://blog.ijun.org/2014/11/install-epel-and-additional.html
https://fedoraproject.org/wiki/EPEL

Subscribing to the IUS Community Project Repository:

# curl 'https://setup.ius.io/' -o setup-ius.sh
# bash setup-ius.sh

# ls -l /etc/yum.repos.d/ius*

-rw-r--r--. 1 root root 1150 Apr 16  2015 /etc/yum.repos.d/ius-archive.repo
-rw-r--r--. 1 root root 1131 Apr 16  2015 /etc/yum.repos.d/ius-dev.repo
-rw-r--r--. 1 root root 1073 Apr 16  2015 /etc/yum.repos.d/ius.repo
-rw-r--r--. 1 root root 1150 Apr 16  2015 /etc/yum.repos.d/ius-testing.repo

To find which package provides the ifconfig command:

# yum provides ifconfig

To get the ifconfig command into our system:

# yum -y install net-tools

# ifconfig | awk '/inet /{print $2}'

To get the ss command into our system:

# yum -y install iproute

To install DNS tools:

# yum install bind-utils

Install tmux:
# yum -y install tmux

# vi ~/.tmux.conf

# tmux
or
# tmux a -d

Install vim-enhanced:

It is actually very easy to compile Vim by yourself. Please refer to the following article if you are interested in:

http://blog.ijun.org/2016/07/compile-latest-vim-74-on-centos7.html

# vim --version
-syntax
-python

# yum -y install vim-enhanced

# vim --version
+syntax
+python

# yum list installed | grep -i vim
# yum info vim-enhanced

Install tree:

# yum -y install tree

Install fortune game:

# yum -y install fortune-mod.x86_64

Install Glances:

# yum -y install glances

Install Git:

# yum install git

Or from IUS repo (preferred):

# yum install git2u

Install NetCat:

# yum -y install nmap-ncat
# nc localhost 8080

Install firewalld:

# yum -y install firewalld

(optional)
# yum install firewall-config

Note: If you don't mind using a GUI you could use firewall-config instead. If you need something for the console you will have to use firewall-cmd instead.

# systemctl enable firewalld

# systemctl restart firewalld

Install MariaDB:

# yum install mariadb-server

Setting UTF8 defaults for MySQL:

We recommend against MySQL's utf8 character set, since it does not support 4-byte unicode characters, and strings containing them will be truncated. This is fixed by the newer utf8mb4 character set.

# vim /etc/my.cnf

[mysqld]
# Version 5.5.3 introduced "utf8mb4", which is recommended
collation-server = utf8mb4_general_ci # Replaces utf8_general_ci
character-set-server = utf8mb4 # Replaces utf8

default-storage-engine = InnoDB

max_allowed_packet = 16M

# This option makes InnoDB to store each created table into its own .ibd file.
innodb_file_per_table

# Don't resolve hostnames. All hostnames are IP's or 'localhost'.
skip-name-resolve

#The number of simultaneous clients allowed.
max_connections = 200

# uncomment to disable the InnoDB storage engine
#skip-innodb

innodb_buffer_pool_size = 4G
innodb_additional_mem_pool_size = 16M
innodb_log_file_size = 256M
innodb_log_buffer_size = 8M

# systemctl enable mariadb.service

# systemctl restart mariadb.service

# systemctl is-active mariadb.service

# /usr/bin/mysql_secure_installation

# mysql -u root -p

mysql> GRANT ALL PRIVILEGES ON *.* TO 'test'@'192.168.0.%' IDENTIFIED BY '123456';
mysql> FLUSH PRIVILEGES;

mysql> CREATE DATABASE mydb DEFAULT CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;

Set up .my.cnf configuration file:

# touch ~/.my.cnf
# chmod 600 ~/.my.cnf
# vim ~/.my.cnf

[client]
host = localhost
port = 3306
user = root
password = MyPassword

Add New Rule to firewalld to allow access to MySQL:

# firewall-cmd --permanent --zone=trusted --add-source=192.168.0.1/32
# firewall-cmd --permanent --zone=trusted --add-port=3306/tcp
# firewall-cmd --reload
# firewall-cmd --zone=trusted --list-all

or

# systemctl restart firewalld.service

Check out the zone file to inspect the XML configuration:

# cat /etc/firewalld/zones/public.xml
# cat /etc/firewalld/zones/trusted.xml

Install Apache:

# yum install httpd mod_ssl

Or from IUS repo (preferred):

# yum install httpd24u httpd24u-mod_ssl

# systemctl status httpd

● httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; vendor preset: disabled)

Note: it will tell you if the service starts on boot.

# systemctl enable httpd.service

# systemctl restart httpd.service

# systemctl reload httpd.service

# systemctl -l status httpd.service

# journalctl -xn

# systemctl is-active httpd.service

# apachectl configtest

# httpd -V

# apachectl graceful

httpd service default configuration files:

  • Default config file: /etc/httpd/conf/httpd.conf
  • Configuration files which load modules : /etc/httpd/conf.modules.d/ directory (e.g. PHP)
  • Select MPMs (Processing Model) as loadable modules [worker, prefork (default)] and event: /etc/httpd/conf.modules.d/00-mpm.conf
  • Default ports: 80 and 443 (SSL)
  • Default log files: /var/log/httpd/{access_log,error_log}

Set up a symbolic link:

# cd / ; ln -s var/www/html www

Install PHP:

# yum install php php-mysqlnd php-fpm php-gd php-mbstring php-pdo php-xml php-soap
# yum install php-pear php-devel pcre-devel gcc gcc-c++ make

# systemctl restart httpd.service

Note: you need php-devel pcre-devel gcc make for PHP APC. Try to add httpd-devel if failed.

You need the php-mcrypt to run Magento:

# yum install php-mcrypt

http://blog.ijun.org/2014/11/how-to-install-php-mcrypt-on-centos-7.html

Open port 80 firewall access:

# firewall-cmd --zone=public --add-port=http/tcp
# firewall-cmd --zone=public --add-port=https/tcp

# firewall-cmd --permanent --zone=public --add-port=http/tcp
# firewall-cmd --permanent --zone=public --add-port=https/tcp

# firewall-cmd --reload
or
# systemctl restart firewalld.service

# firewall-cmd --zone=public --list-all

Allow a IP address with a specific port:

# firewall-cmd --zone=public --add-rich-rule='rule family="ipv4" source address="1.2.3.4" port protocol="tcp" port="3306" accept'

To remove the rule:

# firewall-cmd --zone=public --remove-rich-rule='rule family="ipv4" source address="1.2.3.4" port protocol="tcp" port="3306" accept'

Block a IP address:

# firewall-cmd --zone=public --add-rich-rule='rule family="ipv4" source address="1.2.3.4" reject'

To remove the rule:

# firewall-cmd --zone=public --remove-rich-rule='rule family="ipv4" source address="1.2.3.4" reject'

If you get 403 forbidden error, then you probably have problem with SELinux, to deal with Security-Enhanced Linux (SELinux):

# namei -l /var/www/html/magento19

# ls -dZ /var/www/html
drwxr-xr-x. root root system_u:object_r:httpd_sys_content_t:s0 /var/www/html

# chcon -R --reference=/var/www/html /var/www/html/magento19
Or
# chcon -R --type=httpd_sys_content_t /var/www/html/magento19
Or for read and write permission:
# chcon -R -t httpd_sys_rw_content_t /var/www/html/magento19/app/etc

# ps auxwwZ | grep httpd
# ls -dZ /var/www/html/magento19/app/etc
# tail /var/log/audit/audit.log
# tail /var/log/messages

To turn off Security-Enhanced Linux (SELinux):

# setenforce 0

To turn on Security-Enhanced Linux (SELinux):

# setenforce 1

To get the status of a system running SELinux:

# sestatus

Set up Apache MPM and PHP-FPM:

With Apache 2.4, the official module to use is mod_proxy_fcgi instead of the ancient mod_fastcgi. That module, as well as mod_fcgid, were third party modules.

Note: mod_proxy_fcgi now supports network sockets since Apache 2.4.9 ( Unix socket support for mod_proxy_fcgi )

List built-in or shared modules:

# httpd -M | grep -iE 'proxy_module|proxy_fcgi_module|rewrite_module|mpm_event_module|deflate_module|vhost_alias_module|ssl_module'

 deflate_module (shared)
 rewrite_module (shared)
 vhost_alias_module (shared)
 mpm_event_module (shared)
 proxy_module (shared)
 proxy_fcgi_module (shared)
 ssl_module (shared)

List loaded modules:

# httpd -t -D DUMP_MODULES | grep -iE 'proxy_module|proxy_fcgi_module|rewrite_module|mpm_event_module|deflate_module|vhost_alias_module|ssl_module'

 deflate_module (shared)
 rewrite_module (shared)
 vhost_alias_module (shared)
 mpm_event_module (shared)
 proxy_module (shared)
 proxy_fcgi_module (shared)
 ssl_module (shared)

Edit mpm.conf:

# vim /etc/httpd/conf.modules.d/00-mpm.conf

Comment out the following line:

LoadModule mpm_prefork_module modules/mod_mpm_prefork.so

Uncomment the following line:

LoadModule mpm_event_module modules/mod_mpm_event.so

Make sure the following two lines exist:

# grep -E 'mod_proxy.so|mod_proxy_fcgi' /etc/httpd/conf.modules.d/00-proxy.conf

LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_fcgi_module modules/mod_proxy_fcgi.so

Add the "if checking" surround the following three lines:

# vim /etc/httpd/conf.d/php.conf

<IfModule mod_php5.c>
  <FilesMatch \.php$>
    SetHandler application/x-httpd-php
  </FilesMatch>
</IfModule>

Add the "if checking" surround the following two lines:

# vim /etc/httpd/conf.d/php.conf

<IfModule mod_php5.c>
  php_value session.save_handler "files"
  php_value session.save_path    "/var/lib/php/session"
</IfModule>

Change the following line:

# vim /etc/httpd/conf/httpd.conf

<Directory "/var/www/html">
  AllowOverride All

  # New directive needed in Apache 2.4.3: 
  Require all granted
</Directory>

Create and Edit the vhosts file:

Apache supports talking to php-fpm through SetHandler directive since Apache 2.4.9. We no longer need to use the ProxyPassMatch directive.

As the ProxyPassMatch directive is evaluated as the very beginning of each request:
- AddType (for MultiView) or DirectoryIndex directives are not usable
- right management per directory is not available
- each Alias directive needs another proxy rule

The SetHandler directive, evaluated later, is much more flexible / usable.

To redirect the PHP scripts to the FPM server:

<FilesMatch \.php$>
         SetHandler "proxy:fcgi://127.0.0.1:9000"
</FilesMatch>

Note: You will also need to enable the following modules:

LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_fcgi_module modules/mod_proxy_fcgi.so

Warning: if you remove or disable mod_php, you also need to remove all the php_value and php-flag directives:

<IfModule  mod_php5.c>
        php_value session.save_handler "files"
        php_value session.save_path    "/var/lib/php/session"
        php_value soap.wsdl_cache_dir  "/var/lib/php/wsdlcache"
</IfModule>

Note: For more detail, visit https://blog.remirepo.net/post/2014/03/28/PHP-FPM-and-HTTPD-2.4-improvement

# vim /etc/httpd/conf.d/httpd-vhosts.conf

#
# Use name-based virtual hosting.
#
NameVirtualHost *:80

#
# VirtualHost example:
# Almost any Apache directive may go into a VirtualHost container.
# The first VirtualHost section is used for all requests that do not
# match a ServerName or ServerAlias in any <VirtualHost> block.
#
<VirtualHost *:80>
    ServerAdmin webmaster@dummy-host.example.com
    DocumentRoot "/var/www/html/host_not_found"
    ErrorLog "/var/log/httpd/host_not_found-error_log"
    CustomLog "/var/log/httpd/host_not_found-access_log" common
</VirtualHost>

<VirtualHost *:80>
    ServerAdmin webmaster@dummy-host.example.com
    DocumentRoot "/var/www/html/magento1.9.1"
    ServerName us.centos.local

    ### Disable PHP script execution for this directory. We don't want to reverse-proxy this subdirectory.
    <Location "/var">
      ProxyPass !
    </Location>

    ### Disable PHP script execution for this directory. We don't want to reverse-proxy this subdirectory.
    <Location "/media">
      ProxyPass !
    </Location>

    ProxyPassMatch ^/(.*\.php(/.*)?)$ fcgi://127.0.0.1:9000/var/www/html/magento1.9.1/$1

    SetEnv MAGE_RUN_CODE "us_centos_local"
    SetEnv MAGE_RUN_TYPE "website"

    ### a request for / will need to be mapped to a resource on the fcgi backend. Failure to address this may cause a blank response, commonly known as a WSOD (White Screen of Death), especially if only a request URI containing the php extension is proxied, such as this example. The processing chain will first map a request for / to /index.php, then proxy to the PHP-FPM backend correctly.
    DirectoryIndex /index.php index.php index.html index.htm

    ErrorLog "/var/log/httpd/us.centos.local-error_log"
    CustomLog "/var/log/httpd/us.centos.local-access_log" common
</VirtualHost>

Setting up an SSL secured Web server:

<VirtualHost *:443>
    SSLEngine on
    SSLCertificateFile /etc/pki/tls/certs/mydomain.com.crt
    SSLCertificateKeyFile /etc/pki/tls/private/mydomain.com.key
    SSLCertificateChainFile /etc/pki/tls/certs/gd_bundle-mydomain.com.crt

    ServerAdmin webmaster@dummy-host.example.com
    DocumentRoot "/var/www/html/magento1.9.1"
    ServerName us.centos.local

    ### we don't want to reverse-proxy this subdirectory.
    <Location "/var">
      ProxyPass !
    </Location>

    ### we don't want to reverse-proxy this subdirectory.
    <Location "/media">
      ProxyPass !
    </Location>

    ProxyPassMatch ^/(.*\.php(/.*)?)$ fcgi://127.0.0.1:9000/var/www/html/magento1.9.1/$1

    SetEnv MAGE_RUN_CODE "us_centos_local"
    SetEnv MAGE_RUN_TYPE "website"

    ErrorLog "/var/log/httpd/us.centos.local443-error_log"
    CustomLog "/var/log/httpd/us.centos.local443-access_log" common
</VirtualHost>

Make sure the security context of the certification files are cert_t:

# cd /etc/pki/tls/certs/mydomain.com
# chcon -t cert_t *

If you do not see the correct security context, you will see the following message when restarting Apache:

Mar 16 23:58:00 ip-172-31-21-55 httpd[22680]: AH00526: Syntax error on line 19 of /etc/httpd/conf.d/httpd-vhosts.conf:
Mar 16 23:58:00 ip-172-31-21-55 httpd[22680]: SSLCertificateFile: file '/etc/pki/tls/certs/mydomain.com/b1210d10x4d812c5.crt' does not exist or is empty
Mar 16 23:58:00 ip-172-31-21-55 systemd[1]: httpd.service: main process exited, code=exited, status=1/FAILURE
Mar 16 23:58:00 ip-172-31-21-55 systemd[1]: Failed to start The Apache HTTP Server.
Mar 16 23:58:00 ip-172-31-21-55 systemd[1]: Unit httpd.service entered failed state.
Mar 16 23:58:00 ip-172-31-21-55 systemd[1]: httpd.service failed.

Restart Apache:

# systemctl reload httpd.service

# httpd -t -D DUMP_VHOSTS

To enable gzip compression:

# egrep 'deflate|header' /etc/httpd/conf.modules.d/00-base.conf

LoadModule deflate_module modules/mod_deflate.so
LoadModule headers_module modules/mod_headers.so

# httpd -t -D DUMP_MODULES | grep deflate

deflate_module (shared)

# vim /etc/httpd/conf.d/mod_deflate.conf

<IfModule mod_deflate.c>
  AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css text/js application/javascript application/x-javascript application/x-httpd-php
</IfModule>

# systemctl restart httpd.service

Install Xdebug for debugging PHP:

# pecl install Xdebug

# vim /etc/php.d/xdebug.ini

; Enable xdebug extension module
zend_extension=xdebug.so
;zend_extension=/usr/lib64/php/modules/xdebug.so

xdebug.default_enable=1
xdebug.remote_enable=1
xdebug.remote_handler=dbgp
xdebug.remote_host=localhost
xdebug.remote_port=9009
xdebug.remote_log=/tmp/xdebug.log
xdebug.remote_connect_back=0
xdebug.remote_autostart=0
xdebug.remote_mode=req

xdebug.max_nesting_level=1000

xdebug.var_display_max_depth = 5
xdebug.var_display_max_children = 256
xdebug.var_display_max_data = 1024

or

zend_extension="/usr/lib64/php/modules/xdebug.so"

; When this setting is set to on, the tracing of function calls will be enabled just before the script is run. This makes it possible to trace code in the auto_prepend_file.
xdebug.auto_trace = 1
xdebug.trace_output_dir = "/tmp"
xdebug.collect_params = 4

; Enables Xdebug's profiler which creates files in the profile output directory. Those files can be read by KCacheGrind to visualize your data.
xdebug.profiler_enable = 1
xdebug.profiler_output_dir = "/tmp"

; Controls the protection mechanism for infinite recursion protection. The value of this setting is the maximum level of nested functions that are allowed before the script will be aborted.
xdebug.max_nesting_level = 100

; shows a human readable / computer readable trace file.
xdebug.trace_format = 0

; This setting tells Xdebug to gather information about which variables are used in a certain scope. This analysis can be quite slow as Xdebug has to reverse engineer PHP's opcode arrays. This setting will not record which values the different variables have, for that use xdebug.collect_params. This setting needs to be enabled only if you wish to use xdebug_get_declared_vars().
xdebug.collect_vars = 0

; When set to '1' the trace files will be appended to, instead of being overwritten in subsequent requests.
; Note: this option can be useful if you could not find your function calls anywhere.
xdebug.trace_options = 1

To search all other php modules:

# yum search php

Edit php.ini:

# vim /etc/php.ini

cgi.fix_pathinfo = 0

The default value is 1, which is an extremely insecure setting because it tells PHP to attempt to execute the closest file it can find if a PHP file does not match exactly. This basically would allow users to craft PHP requests in a way that would allow them to execute scripts that they shouldn't be allowed to execute.

Note: if I set it to "cgi.fix_pathinfo = 0", I would get "Access denied (403)" (see security.limit_extensions) or no input file specified error when setting up Magento. You can either:

1. commented out the cgi.fix_pathinfo = 0 line.
2. set cgi.fix_pathinfo = 1
3. try to set "security.limit_extensions = " in the /etc/php-fpm.d/www.conf file.

http://stackoverflow.com/questions/23390531/access-denied-403-for-php-files-with-nginx-php-fpm
http://serverfault.com/questions/627903/is-the-php-option-cgi-fix-pathinfo-really-dangerous-with-nginx-php-fpm

display_errors = On
log_errors = On
error_log = /var/log/php_errors.log

Note: make sure you do:

# touch /var/log/php_errors.log
# chmod 660 /var/log/php_errors.log
# chown root:apache /var/log/php_errors.log

# chcon -t httpd_log_t /var/log/php_errors.log
Or
# chcon -u system_u -t httpd_log_t /var/log/php_errors.log

Install XCache:

XCache is a fast, stable ​PHP opcode cacher that has been proven and is now running on production servers under high load. It is tested (on linux) and supported on all of the latest ​PHP release branches such as PHP_5_1 PHP_5_2 PHP_5_3 PHP_5_4 PHP_5_5. It is more stable than APC.

Warning: APC would cause segfault segmentation fault. Use XCache instead.

# yum install php-xcache xcache-admin

# systemctl restart httpd
# systemctl restart php-fpm
# php -v

PHP 5.4.16 (cli) (built: Oct 31 2014 12:59:36)
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2013 Zend Technologies
    with XCache v3.1.1, Copyright (c) 2005-2014, by mOo
    with XCache Optimizer v3.1.1, Copyright (c) 2005-2014, by mOo
    with XCache Cacher v3.1.1, Copyright (c) 2005-2014, by mOo
    with XCache Coverager v3.1.1, Copyright (c) 2005-2014, by mOo

# echo -n "Your Password" | md5sum

5afd8756ebeda48acf7eb645503dae60

# vim /etc/php.d/xcache.ini

[xcache]

xcache.admin.user = "admin name"
xcache.admin.pass = "5afd8756ebeda48acf7eb645503dae60"

xcache.size = 60M

; This number divides total cache size into threads in order to increase the efficiency. If you have 128M xcache.size and you set the count as 4, that means each thread will manage 32M size of cache.
xcache.count = 1

xcache.cacher = On
xcache.stat = On
xcache.optimizer = On

# cp -r /usr/share/xcache/ /var/www/html/

# systemctl restart php-fpm

http://localhost/xcache/

Install APC:

Warning: APC would cause segfault segmentation fault. Use XCache instead.

# pecl install apc

# vim /etc/php.d/apc.ini

; Enable APC for PHP
extension=apc.so
apc.enabled=1

; The number of seconds a cache entry is allowed to idle in a slot before APC dumps the cache
apc.ttl=72000
apc.user_ttl=72000
apc.gc_ttl=3600

; Size of memory for apc ( 1024 M)
apc.shm_size=1024M

; Enable apc stats.
apc.stat=1

; Enable APC for command line php operations.
apc.enable_cli=1

; Allow 2 seconds after a file is created before it is cached. This will prevent premature PHP pages to get cached.
apc.file_update_protection=2

; Maximum size of single file that apc can store.
apc.max_file_size=1M

; Maximum number of files APC can store ( rotation).
apc.num_files_hint=200000

; Maximum number of users data entries that APC can store.
apc.user_entries_hint=20000

Copy the apc.php file:

# cp /usr/share/pear/apc.php /var/www/html

Set up php-fpm:

Apach 2.4.8 mod_proxy: Added support for unix domain sockets as the backend server endpoint.

# vim /etc/php-fpm.d/www.conf

If you are using Apach 2.4.8 or above, please change the following line from:

listen = 127.0.0.1:9000

To:

listen = /var/run/php-fpm/php-fpm.sock

Now, there are different ways to actually forward requests for .php files to this module, ranging from everything (using ProxyPass) to very specific or rewritten files or patterns (using mod_rewrite with the [P] flag).

The method I chose (using ProxyPassMatch) lies somewhere in between these in complexity and flexibility, since it allows you to set one rule for all PHP content of a specific vhost, but will only proxy .php files (or URLs that contain the text .php somewhere in the request).

TCP socket (IP and port) approach

Edit the configuration for a vhost of your choice, and add the following line to it:

# vim /etc/httpd/conf.d/httpd-vhosts.conf

ProxyPassMatch ^/(.*\.php(/.*)?)$ fcgi://127.0.0.1:9000/path/to/your/documentroot/$1

### a request for / will need to be mapped to a resource on the fcgi backend. Failure to address this may cause a blank response, commonly known as a WSOD (White Screen of Death), especially if only a request URI containing the php extension is proxied, such as this example. The processing chain will first map a request for / to /index.php, then proxy to the PHP-FPM backend correctly.
    DirectoryIndex /index.php index.php index.html index.htm

Note: please do change /path/to/your/documentroot to for example /var/www/html/drupal8

Look confusing ? Let's run through it:

ProxyPassMatch

only proxy content that matches the specified regex pattern; in this case:

^/(.*\.php(/.*)?)$

from the documentroot onwards, match everything ending in .php (with the dot escaped), optionally followed by a slash and any continued path you like (some applications use this so-called PathInfo to pass arguments to the php script.)

The ^ (caret) and $ (dollar) signs are used to anchor both the absolute start and end of the URL, to make sure no characters from the request escape our pattern match.

The nested parentheses enable us to refer to the entire request-URI (minus the leading slash) as $1, while still keeping the trailing pathinfo optional.

fcgi://127.0.0.1:9000

forward via mod_proxy_fcgi, using the fastCGI protocol, to the port our php-fpm daemon is listening on.

This determines which fastcgi pool will serve requests proxied by this rule.

/path/to/your/documentroot/

IMPORTANT! This must exactly match the real filesystem location of your php files, because that is where the php-fpm daemon will look for them.

php-fpm just interprets the php files passed to it; it is not a web server, nor does it understand your web servers' namespace, virtualhost layout, or aliases.

IMPORTANT! Read the above again

$1

expands to the entire request-URI from the original request, minus the leading slash (because we already added that above.)

DirectoryIndex /index.php index.php index.html index.htm

Note: a request for / will need to be mapped to a resource on the fcgi backend. Failure to address this may cause a blank response, commonly known as a WSOD (White Screen of Death), especially if only a request URI containing the php extension is proxied, such as this example. The processing chain will first map a request for / to /index.php, then proxy to the PHP-FPM backend correctly.

unix domain socket (UDS) approach

Edit the configuration for a vhost of your choice, and add the following line to it:

# vim /etc/httpd/conf.d/httpd-vhosts.conf

ProxyPassMatch ^/(.*\.php(/.*)?)$ unix:/path/to/socket.sock|fcgi://127.0.0.1:9000/path/to/your/documentroot/

unix:/path/to/socket.sock

the path to your fpm socket

Note that with this approach, the captured request URI ($1) is not passed after the path

Enable php-fpm to start on boot:

# systemctl enable php-fpm.service

Start our PHP processor:

# systemctl restart php-fpm.service
# systemctl restart httpd.service

Test PHP:

# php -r "echo 'hi';";

Check the PHP-FPM setting:

<?php
echo phpinfo();
?>

You should see the message: Server API: FPM/FastCGI

# httpd -V

Server MPM:     event

To create a locked user account:

# useradd dev -m -c 'git user'

Unlock the account by issuing the passwd command to assign a password and set password aging guidelines:

# passwd dev

Add a new group called web:

# groupadd web

Add the dev user to the web group:

# usermod -a -G web dev

Show The Groups a User Is In:

# groups dev
# id -Gn dev

Find out the primary group of a user:

# getent group dev

To allow Apache to connect network and sendmail send email:

# setsebool -P httpd_can_network_connect 1
# setsebool -P httpd_can_sendmail 1

Note: -P in the above command means Persistent (across reboots)

# getsebool -a | grep -i httpd_can

httpd_can_network_connect --> on
httpd_can_sendmail --> on

# sestatus -b | grep httpd_can

httpd_can_network_connect                   on
httpd_can_sendmail                          on

Install Memcached:

# yum install memcached
# yum install php-pecl-memcached

# systemctl enable memcached.service
# systemctl restart memcached.service

# memcached-tool localhost:11211 display
# memcached-tool localhost:11211 stats
# memcached-tool localhost:11211 dump

Install redis server:

# yum install redis
# yum install php-pecl-redis

Two important redis server configuration files:

# less /etc/redis.conf
# less /etc/redis-sentinel.conf

Start the Redis server:

# systemctl start redis.service

Check the running status of Redis server:

# systemctl status redis.service

To test the installation of Redis:

# redis-cli ping

PONG

To enable Redis server at system's booting time:

# systemctl enable redis.service

To get the listening port 6379 of Redis server:

# ss -nlp | grep redis

To install Redis PHP extension:

# pecl install redis

Add the following line to /etc/php.d/redis.ini:

# echo 'extension=redis.so' >> /etc/php.d/redis.ini

Check to see if Redis PHP extension is installed:

# pecl list | grep redis

redis   2.2.7   stable

Restart Apache and PHP-FPM:

# systemctl restart httpd.service
# systemctl restart php-fpm.service

To see if Redis extension is being loaded by PHP:

# php -m | grep redis

To allow Apache to connect to the Redis server:

# setsebool -P httpd_can_network_connect 1

Note: If you have turned on Security-Enhanced Linux (SELinux), httpd scripts by default are not allowed to connect out to the network.

To list all Redis Databases:

# redis-cli info keyspace

To clear remove delete all data from a particular Redis database:

# redis-cli

127.0.0.1:6379> info keyspace
127.0.0.1:6379> select 0
127.0.0.1:6379> keys *
127.0.0.1:6379> flushdb
127.0.0.1:6379> keys *

To clear remove delete all data from all Redis database:

# redis-cli flushall

Dumping all key/value pairs in a Redis db:

# redis-cli -n 0 keys \*

# redis-cli -n 0 keys \* | xargs -n 1 redis-cli dump

Note: the 0 is the database number.

To store PHP sessions in Redis:

Storing PHP session files in RAM can be much more efficient than storing on disk and can also save some IO. To configure this, you should modify the main php.ini file and change session.save_handler to redis.

# vim /etc/php.ini

session.save_handler = redis

session.save_path = "tcp://127.0.0.1:6379"

# systemctl restart php-fpm

# php -r 'echo phpinfo();' | grep redis

Registered save handlers => files user redis
session.save_handler => redis => redis

# vim test.php

<?php
session_start();

$_SESSION['favcolor'] = 'green';

echo '<pre>' . print_r($_SESSION, TRUE) . '</pre>';
?>

# php test.php

# redis-cli info keyspace
# Keyspace
db0:keys=68,expires=39,avg_ttl=2977110
db2:keys=427,expires=427,avg_ttl=1856886

# redis-cli -n 0 keys \*| grep -i session

PHPREDIS_SESSION:vhauaf8qpdj146kirsbivrh4i7

Note: the 0 is the database number.

Redis setup hints

  • We suggest deploying Redis using the Linux operating system. Redis is also tested heavily on osx, and tested from time to time on FreeBSD and OpenBSD systems. However Linux is where we do all the major stress testing, and where most production deployments are working.
  • Make sure to set the Linux kernel overcommit memory setting to 1. Add vm.overcommit_memory = 1 to /etc/sysctl.conf and then reboot or run the command sysctl vm.overcommit_memory=1 for this to take effect immediately.
  • Make sure to disable Linux kernel feature transparent huge pages, it will affect greatly both memory usage and latency in a negative way. This is accomplished with the following command: echo never > sys/kernel/mm/transparent_hugepage/enabled.
  • Make sure to setup some swap in your system (we suggest as much as swap as memory). If Linux does not have swap and your Redis instance accidentally consumes too much memory, either Redis will crash for out of memory or the Linux kernel OOM killer will kill the Redis process.
  • Set an explicit maxmemory option limit in your instance in order to make sure that the instance will report errors instead of failing when the system memory limit is near to be reached.
  • If you are using Redis in a very write-heavy application, while saving an RDB file on disk or rewriting the AOF log Redis may use up to 2 times the memory normally used. The additional memory used is proportional to the number of memory pages modified by writes during the saving process, so it is often proportional to the number of keys (or aggregate types items) touched during this time. Make sure to size your memory accordingly.
  • Use daemonize no when run under daemontools.
  • Even if you have persistence disabled, Redis will need to perform RDB saves if you use replication, unless you use the new diskless replication feature, which is currently experimental.
  • If you are using replication, make sure that either your master has persistence enabled, or that it does not automatically restarts on crashes: slaves will try to be an exact copy of the master, so if a master restarts with an empty data set, slaves will be wiped as well.

Running Redis on EC2

  • Use HVM based instances, not PV based instances.
  • Don't use old instances families, for example: use m3.medium with HVM instead of m1.medium with PV.
  • The use of Redis persistence with EC2 EBS volumes needs to be handled with care since sometimes EBS volumes have high latency characteristics.
  • You may want to try the new diskless replication (currently experimetnal) if you have issues when slaves are synchronizing with the master.

Reference:

http://blog.ijun.org/2014_04_01_archive.html

http://blog.ijun.org/2014/11/configuring-magento-to-use-redis.html

http://blog.ijun.org/2014/12/install-apache-24-php-56-and-mysql-56.html

http://redis.io/topics/admin

http://www.cyberciti.biz/faq/howto-install-linux-apache-mariadb-php-lamp-stack-on-centos7-rhel7/

http://serverfault.com/questions/629937/centos-7-apache2-httpd-mod-fastcgi-installation-impossible

http://blog.famillecollet.com/post/2014/08/01/Apache-httpd-server-2.4.10-and-PHP-FPM-5.6-in-Fedora-21

https://wiki.apache.org/httpd/PHP-FPM

http://sharadchhetri.com/2014/10/04/install-redis-server-centos-7-rhel-7/

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/s1-networkscripts-interfaces.html

http://technovergence-en.blogspot.ca/2012/03/mysql-from-utf8-to-utf8mb4.html

Sunday, September 23, 2018

Golang, mysql: Error 1040: Too many connections too many open files

Golang, mysql: Error 1040: Too many connections too many open files

  • Opening and closing databases can cause exhaustion of resources.
  • Failing to read all rows or use rows.Close() reserves connections from the pool.
  • Using Query() for a statement that doesn’t return rows will reserve a connection from the pool.
  • Failing to be aware of how prepared statements work can lead to a lot of extra database activity.

Check MySQL connections:

mysql> SHOW PROCESSLIST;

mysql> SHOW STATUS LIKE '%connections%';

mysql> SHOW STATUS LIKE '%threads%';

Check network connection files:

# lsof -i

Set some connection limits in Go code:

db.SetMaxOpenConns(1000)
db.SetMaxIdleConns(300)
db.SetConnMaxLifetime(0)

Release the resource after used:

rows, err := db.Query("select name from beehives")

if err != nil {
    panic(err)
}   
    
defer rows.Close()

Reference:

https://stackoverflow.com/questions/28135580/golang-mysql-error-1040-too-many-connections

http://go-database-sql.org/surprises.html

http://go-database-sql.org/prepared.html

https://access.redhat.com/solutions/1160343

Saturday, September 22, 2018

Add Swap to a Amazon EC2 instance with an EBS (Elastic Block Store) volume

The Amazon EC2 instance does not come with the swap partition by default. You will need to add the swap or paging space manually.

Swap space are useful for systems having less memory (RAM). If your system facing problem of lack of memory continuously and you don’t want to increase memory on server, Then it can be helpful to enable swap in your system. Swap is comparatively much slower than physical memory but operating system uses swap space in case system goes out of memory. To know more about working of swap visit here.

Creating a swap file in current file system:

# dd if=/dev/zero of=/myswap bs=1M count=4096

Note: if - input file.
Note: of - output file.
Note: bs - block size.

# mkswap /myswap
# chown root:root /myswap
# chmod 0600 /myswap

# swapon /myswap

# free -h

              total        used        free      shared  buff/cache   available
Mem:           3.8G        940M        115M        5.6M        2.8G        2.6G
Swap:          4.0G          0B        4.0G

# swapon -s

Filename                                Type            Size    Used    Priority
/myswap                                 file    4194300 0       -1

To make the swap enable on system boot, run the following command:

# sh -c "echo /myswap swap swap defaults 0 0 >> /etc/fstab"

Or edit the /etc/fstab:

# vim /etc/fstab

/myswap   swap   swap   defaults  0 0

To verify the swap:

# cat /etc/fstab | grep -i swap

/myswap swap swap defaults 0 0

# cat /proc/meminfo | grep -i swap

SwapCached:            0 kB
SwapTotal:       4194300 kB
SwapFree:        4194300 kB

To check the current system's swappiness:

Swappiness is a ratio of how often the system will write to the swapfile: if set to zero, the system will only swap to avoid running out of memory (the error above); if set to 100, the system will attempt to swap all the time. The default is set at 60. Since we want to utilize the swap only when necessary.

The Linux kernel provides a tweakable setting that controls how often the swap file is used, called swappiness.

A swappiness setting of zero means that the disk will be avoided unless absolutely necessary (you run out of memory), while a swappiness setting of 100 means that programs will be swapped to disk almost instantly.

Ubuntu system comes with a default of 60, meaning that the swap file will be used fairly often if the memory usage is around half of my RAM.

# cat /proc/sys/vm/swappiness

30

To configure swappiness:

# sh -c "echo vm.swappiness = 0 >> /etc/sysctl.conf && sysctl -p"

Add the swap space to a second disk instead of the current disk:

If you would like to add the swap space to a second disk, first we need to add extra disk in our system first. In my case new disk mounted as /dev/xvdd (It may change in your case). Then, run the following commands:

# mkswap -f /dev/xvdd
# swapon /dev/xvdd

# vim /etc/fstab

dev/xvdd   swap   swap   defaults  0 0

If at all possible, I'd advise not to use swap on EC2 unless you're 99% certain you won't have to use it (I.E. it's only there for emergency). When we disabled swap on some of our EC2 instances our monthly EBS IO costs probably halved.

You are right, the Ubuntu EC2 EBS images don't come with swap space configured (for 11.04 at least). The "regular" instance-type images do have a swap partition, albeit only 896 MB on the one I tested.

If some process blows up and you don't have swap space, your server could come to a crawling halt for a good while before the OOM killer kicks in, whereas with swap, it merely gets slow. For that reason, I always like to have swap space around, even with enough RAM. Here's your options:

Create an EBS volume (2-4 times the size of your RAM), attach it to your instance (I like calling it /dev/xvdm for "memory"), sudo mkswap /dev/xvdm, add it to fstab, sudo swapon -a, and you're good to go. I have done this before and it works fine, and it is probably a bit faster than using a swap file, but for a server that doesn't normally depend on swap performance, I personally think the minor performance improvement is not worth the added complexity of having to attach a volume. (Update: It's probably not faster than a swap file on instance storage, since EBS has become known for lousy and unpredictable performance.)

Or you might be able to repartition your disk to add a swap partition, though this might require creating a new AMI. I have not been able to do this in a running instance, because I cannot unmount the root file system, and I do not even have access to the disk device (/dev/xvda), only the partition (xvda1).

Or you can create a swap file. This is my preferred solution right now.

# dd if=/dev/zero of=/var/swapfile bs=1M count=2048 &&
# chmod 600 /var/swapfile &&
# mkswap /var/swapfile &&
# echo /var/swapfile none swap defaults 0 0 | tee -a /etc/fstab &&
# swapon -a

Done. :) I know a lot of people feel icky about using files instead of partitions, but it certainly works well enough as emergency swap space.

Reference:

http://tecadmin.net/add-swap-partition-on-ec2-linux-instance/
http://stackoverflow.com/questions/17173972/how-do-you-add-swap-to-an-ec2-instance
http://askubuntu.com/questions/103915/how-do-i-configure-swappiness
http://serverfault.com/questions/218750/why-dont-ec2-ubuntu-images-have-swap
http://danielgriff.in/2014/add-swap-space-to-ec2-to-increase-performance-and-mitigate-failure/

How to extract deb package

How to extract deb package

$ dpkg -x mysql-cluster-community-server_7.6.7-1ubuntu16.04_amd64.deb ~/tmp/out

or

$ ar -xv mysql-cluster-community-server_7.6.7-1ubuntu16.04_amd64.deb

Increase MySQL maximum connection limit

Increase MySQL maximum connection limit

2018-09-22T15:00:42.130042Z 0 [Warning] Changed limits: max_open_files: 1024 (requested 5000)
2018-09-22T15:00:42.130087Z 0 [Warning] Changed limits: max_connections: 214 (requested 500)
2018-09-22T15:00:42.130091Z 0 [Warning] Changed limits: table_open_cache: 400 (requested 2000)

Note: Ubuntu has moved from Upstart to Systemd in version 15.04 and no longer respects the limits in /etc/security/limits.conf for system services. These limits now apply only to user sessions.

# mkdir /etc/systemd/system/mysql.service.d
# vim /etc/systemd/system/mysql.service.d/override.conf

[Service]
LimitNOFILE=infinity
LimitMEMLOCK=infinity

# systemctl daemon-reload
# systemctl restart mysql

Reference:

https://stackoverflow.com/questions/30901041/can-not-increase-max-open-files-for-mysql-max-connections-in-ubuntu-15

Sunday, September 16, 2018

To let other different users login to Amazon's EC2 instance

Solution 1:

On the local machine, get public key for later use:

$ test -f ~/.ssh/id_rsa.pub && cat ~/.ssh/id_rsa.pub || ssh-keygen -t rsa -C "me@example.com" && cat ~/.ssh/id_rsa.pub

On the remote EC2 instance, create a new user and add the new user to sudo group:

# useradd USER_NAME -m -s /bin/bash -c 'admin user' && usermod -aG sudo USER_NAME

# visudo

%sudo ALL=(ALL:ALL) NOPASSWD: ALL
or
USER_NAME ALL=(ALL) NOPASSWD: ALL

# sudo su - USER_NAME

$ mkdir ~/.ssh \
&& chmod 700 ~/.ssh \
&& touch ~/.ssh/authorized_keys \
&& chmod 600 ~/.ssh/authorized_keys \
&& vim ~/.ssh/authorized_keys

On the local machine:

$ ssh -i ~/.ssh/id_rsa -p 22 USER_NAME@1.2.3.4
or
$ mosh --ssh="ssh -i ~/.ssh/id_rsa -p 22" USER_NAME@1.2.3.4

Solution 2:

# vim /etc/ssh/sshd_config

PasswordAuthentication = yes

# systemctl restart sshd.service

Solution 3:

Add a new user:

# useradd testuser -m -c 'test user'

Switch to the new account so that newly created files have the proper ownership:

# sudo su - testuser

$ mkdir ~/.ssh

$ chmod 700 ~/.ssh

Note: this step is very important; without these exact file permissions, you will not be able to log into this account using SSH.

$ touch ~/.ssh/authorized_keys

$ chmod 600 ~/.ssh/authorized_keys

Login to Amazon Web Services console. Then, go to EC2 and create a new key pair: machineName_userName.

It will generate a machineName_userName.pem file for you to download.

Upload machineName_userName.pem to your Linux instance.

Change the permission of the machineName_userName.pem:

# chmod 400 machineName_userName.pem

Retrieving the Public Key for Your Key Pair on Linux:

# ssh-keygen -y

When prompted to enter the file in which the key is, specify the path to your .pem file; for example:

/path_to_key_pair/machineName_userName.pem

The command returns the public key:

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE

Edit the authorized_keys file with your favorite text editor and paste the public key for your key pair into the file:

# sudo su - testuser

$ vim ~/.ssh/authorized_keys

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE

Remove the private key from the server if you do not need it anymore:

# rm /path_to_key_pair/machineName_userName.pem

Reference:

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/managing-users.html
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html#how-to-generate-your-own-key-and-import-it-to-aws

Saturday, September 15, 2018

Building MySQL from Source Code

Building MySQL from Source Code

# apt-get update && apt-get install build-essential cmake bison -y

# cd /usr/local/src \
&& git clone https://github.com/mysql/mysql-server.git --depth 1 \
&& mkdir bld \
&& cd bld \
&& cmake ../mysql-server \
-DDOWNLOAD_BOOST=1 \
-DWITH_BOOST=/usr/local/src/bld \
&& make

Persistent key-value database written in Go

Persistent key-value database written in Go

badger - https://github.com/dgraph-io/badger/

Note: https://blog.dgraph.io/post/badger/

bbolt - https://github.com/etcd-io/bbolt

MySQL backup and replication tools

MySQL backup and replication tools

mydumper

https://github.com/maxbube/mydumper

Percona XtraBackup

https://www.percona.com/software/mysql-database/percona-xtrabackup

Percona MySQL-AutoXtraBackup

https://github.com/Percona-Lab/MySQL-AutoXtraBackup

https://www.percona.com/blog/2017/11/27/perconalab-autoxtrabackup-v1-5-0-release/

mysqlbinlog

# mysqlbinlog --result-file=test.log /var/log/mysql/mysql-bin.000001

Note: You may edit the result file and delete any statements you don't want to execut. Then, do mysql -u root -p < test.log

# mysqlbinlog --result-file=test.log --base64-output=DECODE-ROWS /var/log/mysql/mysql-bin.000001
# mysqlbinlog --result-file=test.log -v /var/log/mysql/mysql-bin.000001
# mysqlbinlog --result-file=test.log -vv /var/log/mysql/mysql-bin.000001

Note: Do more research on global transaction identifier (GTID) vs binary log position

Get binary log from the remote server:

# mysqlbinlog --read-from-remote-server --host=192.168.101.2 -p mysqld-bin.000001

Note: https://www.percona.com/blog/2012/01/18/backing-up-binary-log-files-with-mysqlbinlog/

The output of mysqlbinlog can be used as the input of the mysql client to redo the statements contained in the binary log:

# cd /var/log/mysql
# mysqlbinlog mysql-bin.000001 | mysql -u root -p

canal

https://github.com/alibaba/canal

Pingcap syncer:

https://github.com/pingcap/docs/blob/master/tools/syncer.md

To Embed Static Assets in Go

To Embed Static Assets in Go

Requirements:

Compression
Optional decompression
Loading from the local file system
Reproducible builds
Config file
http.FileSystem Interface

vfsgen - https://github.com/shurcooL/vfsgen
fileb0x - https://github.com/UnnoTed/fileb0x
go-assets - https://github.com/jessevdk/go-assets

Reference:

https://tech.townsourced.com/post/embedding-static-files-in-go/

Saturday, September 8, 2018

Convert string to hexadecimal on command line

Convert string to hexadecimal on command line

$ echo -n "Hello" | od -A n -t x1

48 65 6c 6c 6f

Thursday, September 6, 2018

How to avoid Go gotchas

a gotcha is a valid construct in a system, program or programming language that works as documented but is counter-intuitive and almost invites mistakes because it is both easy to invoke and unexpected or unreasonable in its outcome (source: wikipedia)

How to avoid Go gotchas
https://divan.github.io/posts/avoid_gotchas/

Understand Go pointers in less than 800 words or your money back
https://dave.cheney.net/2017/04/26/understand-go-pointers-in-less-than-800-words-or-your-money-back

There is no pass-by-reference in Go
https://dave.cheney.net/2017/04/29/there-is-no-pass-by-reference-in-go

Pointers in Go
https://dave.cheney.net/2014/03/17/pointers-in-go

Should methods be declared on T or *T
https://dave.cheney.net/2016/03/19/should-methods-be-declared-on-t-or-t

HOW EVERYTHING IN GO IS PASSED BY VALUE ?
https://techgita.com/2018/08/25/how-everything-in-go-is-passed-by-value/

50 Shades of Go: Traps, Gotchas, and Common Mistakes for New Golang Devs
http://devs.cloudimmunity.com/gotchas-and-common-mistakes-in-go-golang/

Go traps
https://go-traps.appspot.com/

Go Data Structures
http://research.swtch.com/godata

Go Data Structures: Interfaces
http://research.swtch.com/interfaces

Go Slices: usage and internals
https://blog.golang.org/go-slices-usage-and-internals

Gopher Puzzlers
http://talks.godoc.org/github.com/davecheney/presentations/gopher-puzzlers.slide

Don't use Go's default HTTP client (in production)
https://medium.com/@nate510/don-t-use-go-s-default-http-client-4804cb19f779

The complete guide to Go net/http timeouts
https://blog.cloudflare.com/the-complete-guide-to-golang-net-http-timeouts/

How to organize the go struct, in order to save memory
https://medium.com/@felipedutratine/how-to-organize-the-go-struct-in-order-to-save-memory-c78afcf59ec2