Blog

  • Firefox

    Firefox profile

  • Firefox profile

    Here is shortcut i use for my firefox profile

    boby@hon-pc-01:~$ cat  ~/.local/share/applications/firefox-vpn.desktop 
[Desktop Entry]
Version=1.0
Name=Firefox VPN
Comment=Browse the World Wide Web
GenericName=Web Browser
Keywords=Internet;WWW;Browser;Web;Explorer
Exec=firefox -P vpn -private-window --class=Firefox-VPN %u
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=go-home
Categories=GNOME;GTK;Network;WebBrowser;
MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;x-scheme-handler/chrome;video/webm;application/x-xpinstall;
StartupNotify=true
Actions=new-window;new-private-window;

[Desktop Action new-window]
Name=Open a New Window
Exec=firefox -P vpn -new-window

[Desktop Action new-private-window]
Name=Open a New Private Window
Exec=firefox -P vpn -private-window
boby@hon-pc-01:~$

    firefox

  • Encrypt

  • Encrypting a file using OpenSSL

    To encrypt a file, run

    openssl enc -aes-256-cbc -in FILE -out FILE.enc

    To decrypt, use

    openssl enc -d -aes-256-cbc -in FILE.enc -out FILE

    You can use -k option to provide password in commend line itself so it won’t prompt for password.

    Here is a script i use to take backup

    boby@hon-pc-01:~$ cat ~/bin/backup-my-files 
#!/bin/bash

cd $HOME/work/
rm -f myfiles.tar.gz myfiles.tar.gz.openssl
tar --exclude='MY_FILES/.git' -zcvf myfiles.tar.gz MY_FILES
openssl enc -aes-256-cbc -in /home/boby/work/myfiles.tar.gz -out myfiles.tar.gz.openssl

echo "Backup available in folder $HOME/work"
echo "You can decrypt file using"
echo ""
echo "openssl enc -d -aes-256-cbc -in myfiles.tar.gz.openssl -out myfiles.tar.gz"

boby@hon-pc-01:~$

    openssl

    Encrypt

  • MySQL Unknown collation: utf8mb4_unicode_520_ci

    When i restore a MySQL database backup taken on MairaDB 10 on MySQL 5.5, i get error

    root@48b55e4d9b35:/home/boby# mysql -u root -pflashwebhost wp < wp.sql
ERROR 1273 (HY000) at line 356: Unknown collation: 'utf8mb4_unicode_520_ci'
root@48b55e4d9b35:/home/boby#

    To fix this, i changed all instance of utf8mb4_unicode_520_ci in the SQL backup file with utf8mb4_unicode_ci with sed.

    sed -i 's/utf8mb4_unicode_520_ci/utf8mb4_unicode_ci/g'  wp.sql

    mysql

  • Apache SSL

    Here is a non-SSL Apache virtual host.

    <VirtualHost *:80>
    ServerName serverok.in
    ServerAdmin admin@serverok.in
    DocumentRoot /home/serverok.in/html
    CustomLog ${APACHE_LOG_DIR}/serverok.in.log combined
    <Directory "/home/serverok.in/html">
        Options All
        AllowOverride All
        Require all granted
        Order allow,deny
        allow from all
    </Directory>
</VirtualHost>

    To convert it to SSL VirtualHost, first change the port to 443

    Find

    <VirtualHost *:80>

    Replace with

    <VirtualHost *:443>

    Add the above Directory entry

    SSLEngine on
SSLCertificateFile /etc/ssl/DOMAIN.crt
SSLCertificateKeyFile /etc/ssl/DOMAIN.key

    The resulting VirtualHost will look like

    <VirtualHost *:443>
    ServerName serverok.in
    ServerAdmin admin@serverok.in
    DocumentRoot /home/serverok.in/html
    CustomLog ${APACHE_LOG_DIR}/serverok.in.log combined
    SSLEngine on
    SSLProtocol all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1
    SSLCertificateFile /etc/ssl/serverok.in.crt
    SSLCertificateKeyFile /etc/ssl/serverok.in.key
    <Directory "/home/serverok.in/html">
        Options All
        AllowOverride All
        Require all granted
        Order allow,deny
        allow from all
    </Directory>
</VirtualHost>

    For added security, you can use the following config

    SSLEngine on
SSLProtocol             all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1
SSLCipherSuite          ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:!TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384:!TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256:!DSS

    Enable mod_ssl

    If you get the following error

    Invalid command 'SSLEngine', perhaps misspelled or defined by a module not included in the server configuration

    You need to enable mod_ssl, to do this, run

    On Debian/Apache, run

    sudo a2enmod ssl

    Restart Apache

    sudo service apache2 restart

    Force SSL

    You can add the following code to Apache virtualhost for the website

    Redirect 301 / https://domain.ltd/

    ssl

    apache

  • ping

    Ping to Cloud Providers

    http://www.gcping.com
    https://www.cloudping.info
    https://azurespeedtest.azurewebsites.net

    ping: unknown host localhost

    Speedtest China

    https://perfops.net/ping-from-china – Ping from china.

    https://www.chinafy.com/tools/global-speed-test

    http://tool.chinaz.com/speedtest/https://serverok.in/

  • time

    Timestamp in Bash Script

    TIME_STAMP="$(date +%Y%m%d-%H%M%S)"

    for timestamp like 2020-01-23 15:12:45, use

    TIME_STAMP="$(date "+%Y-%m-%d %H:%M:%S")"

    For file name

    date +"%Y-%m-%d-%H-%M-%S"

    Time stamp in PHP

    $now = date("Y-m-d-h:i:s");

    Taking backup

    mysqldump -u root -p'mv9wCAcDE3CnBV' serverok_wp > ~/serverok_wp-`date +"%Y-%m-%d-%H-%M-%S"`.sql

    Alaram/stopwatch

    Time Tracking

  • ntpdate

    ntpdate allows you to update server time with ntp servers.

    To install, run

    apt install ntpdate

    To update server time, run

    ntpdate ntp.ubuntu.com

    Example

    root@ip-172-26-2-47:~# ntpdate ntp.ubuntu.com
 3 Mar 20:32:54 ntpdate[17295]: adjust time server 91.189.91.157 offset -0.000047 sec
root@ip-172-26-2-47:~#

    Auto Update Server time with cronjob

    Method 1

    echo "ntpdate time-a.nist.gov" > /etc/cron.daily/ntpdate
chmod 755 /etc/cron.daily/ntpdate

    Method 2

    Set following cronjob

    30	22	*	*	*	/usr/sbin/ntpdate -b -s 1.pool.ntp.org

    time

  • locale-gen

    To generate 

    locale-gen en_US.UTF-8

    If you get error setlocale: LC_ALL: cannot change locale

    echo "LC_ALL=en_US.UTF-8" >> /etc/environment
echo "LANG=en_US.UTF-8" > /etc/locale.conf
echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen
locale-gen en_US.UTF-8

    bash: locale-gen: command not found
    bash: warning: setlocale: LC_ALL: cannot change locale
    language

  • docker search

    docker search command allows you to search for images in docker hub.

    Example

    root@ok:~# docker search nginx
NAME                                                   DESCRIPTION                                     STARS               OFFICIAL            AUTOMATED
nginx                                                  Official build of Nginx.                        8043                [OK]                
jwilder/nginx-proxy                                    Automated Nginx reverse proxy for docker con…   1284                                    [OK]
richarvey/nginx-php-fpm                                Container running Nginx + PHP-FPM capable of…   526                                     [OK]
jrcs/letsencrypt-nginx-proxy-companion                 LetsEncrypt container to use with nginx as p…   320                                     [OK]
kong                                                   Open-source Microservice & API Management la…   160                 [OK]                
webdevops/php-nginx                                    Nginx with PHP-FPM                              97                                      [OK]
kitematic/hello-world-nginx                            A light-weight nginx container that demonstr…   95                                      
bitnami/nginx                                          Bitnami nginx Docker Image                      44                                      [OK]
linuxserver/nginx                                      An Nginx container, brought to you by LinuxS…   33                                      
1and1internet/ubuntu-16-nginx-php-phpmyadmin-mysql-5   ubuntu-16-nginx-php-phpmyadmin-mysql-5          26                                      [OK]
tobi312/rpi-nginx                                      NGINX on Raspberry Pi / armhf                   18                                      [OK]
wodby/drupal-nginx                                     Nginx for Drupal container image                9                                       [OK]
webdevops/nginx                                        Nginx container                                 8                                       [OK]
blacklabelops/nginx                                    Dockerized Nginx Reverse Proxy Server.          8                                       [OK]
nginxdemos/nginx-ingress                               NGINX Ingress Controller for Kubernetes         8                                       
centos/nginx-18-centos7                                Platform for running nginx 1.8 or building n…   6                                       
nginxdemos/hello                                       NGINX webserver that serves a simple page co…   4                                       [OK]
1science/nginx                                         Nginx Docker images that include Consul Temp…   4                                       [OK]
behance/docker-nginx                                   Provides base OS, patches and stable nginx f…   2                                       [OK]
pebbletech/nginx-proxy                                 nginx-proxy sets up a container running ngin…   2                                       [OK]
toccoag/openshift-nginx                                Nginx reverse proxy for Nice running on same…   1                                       [OK]
travix/nginx                                           NGinx reverse proxy                             1                                       [OK]
mailu/nginx                                            Mailu nginx frontend                            0                                       [OK]
goodguide/nginx-application-proxy                      No-configuration Nginx reverse proxy for a R…   0                                       [OK]
ppc64le/nginx                                          Official build of Nginx.                        0                                       
root@ok:~#

    To see results with 4 or more stars, use

    docker search --filter stars=4

    docker