Creating Objects Create resource: $ kubectl apply -f ./<file_name>.yaml Create from multiple files: $ kubectl apply -f ./<file_name_1>.yaml -f ./<file_name_2>.yaml Create all files in directory: $ kubectl apply -f ./<directory_name> Create from url: $ kubectl apply -f https://<url> Create pod: $ kubectl run <pod_name> –image <image_name> Create pod, then expose it as service: $ kubectl […]
DevOps
How to write Bubble sort in Bash
Bubble sort is a simple algorithm that basically bubbles up the elements of the array. This means that it traverses the array multiple times and swaps the adjacent elements if they are in the wrong order, as in the following diagram: Bubble sort Bash Script Here is a simple bash script for bubble sort algorithm. […]
Strings and Variables in Python
Strings A string is simply a series of characters. Anything inside quotes is considered a string in Python,and you can use single or double quotes around your strings like this: This is a string.” ‘This is also a string.’ Changing Case in a String with Methods One of the simplest tasks you can do with […]
10 Sed (Stream Editor) Command Examples
Sed is a stream editor in a UNIX-like operating system that is used for filtering and transforming text. Sed is derived originally from the basic line editor ‘ed’, an editor you will find on every Unix system but one that is rarely used because of its difficult user interface. How sed Works? As sed is […]
Puppet Server’s Resources Cheat Sheet with Examples
Puppet is an open-source configuration management tool from Puppet Labs. Puppet Resources are the building blocks that puppet uses to model system configurations. The most common Puppet’s Resources are Listed below. file resource Manages local files. Example of file resource is mentioned below: file { ‘/etc/sudoers’: ensure => file, group => ‘root’, owner => ‘root’, […]
Backtick (`) symbol in Linux Shell Scripting
One of the most useful features of shell scripts is the lowly back quote character, usually called the backtick (`) in the Linux world. Be careful—this is not the normal single quotation mark character you are used to using for strings. Because it is not used very often outside of shell scripts, you may not […]
How to Start, Stop and Restart Zimbra Service
The Zimbra server contains Postfix, MySQL, OpenLDAP, ClamAV, and Spam-Assassin, Calendar, and various other features. Zimbra provides a paid option as well as an open source version. The first command in Zimbra mail server which we need to care about zimbra server service status. All services should be running on server. If any of service […]
How to Find and Delete Empty Directories and Files in Linux
1. Find empty directories in the current directory using find -empty: $ find . -type d -empty 2. Use the following command to remove all empty directories under the current directory: $ find . -type d -empty -exec rmdir {} \; 3. Find empty files in the current directory using find -empty: $ find . […]
How to change the audit log path in the MySQL Docker
1. Here we use 5.7.29 Docker image as an example. $ docker load -i mysql-enterprise-server-5.7.29.tar 2. You can bind OS mounts to Docker directory, assume you want to keep the audit logs under /bak/logs directory on the host. $ docker run –name=mysql1 \ –mount type=bind,src=/bak/my.cnf,dst=/etc/my.cnf \ –mount type=bind,src=/bak/data,dst=/var/lib/mysql \ –mount type=bind,src=/bak/logs,dst=/var/lib/logs \ -d mysql/enterprise-server:5.7 3. […]
“Error: Could Not Find A Ready Tiller Pod” – helm error
The Problem Getting “Error: could not find a ready tiller pod” error when trying various helm commands. > helm version Client: &version.Version{SemVer:”v2.14.3″, GitCommit:”0e7f3b6637f7af8fcfddb3d2941fcc7cbebb0085″, GitTreeState:”clean”} Error: could not find a ready tiller pod The Solution This error is caused due to wrong configuration or version mismatch. Follow the procedure to install helm and tiller using the […]