DevOps” as a term was first coined in 2009 by Patrick Debois, who became one of its chief proponents. Simply put, DevOps is a combination of software development and operations — and as its name suggests, it’s a melding of these two disciplines in order to emphasize communication, collaboration, and cohesion between the traditionally separate developer and IT operations teams.
A crontab file is a simple text file containing a list of commands meant to be run at specified times. It is edited using the crontab command. The commands in the crontab file (and their run times) are checked by the cron daemon, which executes them in the system background.
Each user (including root) has a crontab file. The cron daemon checks a user’s crontab file regardless of whether the user is actually logged into the system or not.
Here is an explanation of the crontab format.
- Minute when the process will be started [0-60]
- Hour when the process will be started [0-23]
- Day of the month when the process will be started [1-28/29/30/31]
- Month of the year when the process will be started [1-12]
- Weekday when the process will be started [0-6] [0 is Sunday]
Jenkins is an open source Continuous Integration tool that monitors execution of repetitive jobs, such as building a software project or jobs ran by cron. It’s written in Java programming language and designed to test and report on isolated changes in a larger code in real time.
It is Originally started as Hudson in 2004 but due to a dispute in 2011 they forked and continued under the name, Jenkins.
It can be used to build software, deploy software, or websites to various endpoints or to run unit/behaviour-driven software tests.
So the builds on top of Continuous Integration are Continuous Deployment and Delivery where after the successful tests you will be able to run, instantly and automatically release with the latest version of your codebase. We can say Jenkins makes deployment a non-issue and helps you speed up your development.
Basically, we can say that “Jenkins is a Continuous Integration server which is the best practice of running your tests on a non-developer machine.”
As we know that, “TeamViewer” is a popular software used for system’s (PC) remote access and support . TeamViewer software can connect to any PC or server, so you can remote control your partner’s PC from anywhere by Internet as if you were sitting right in front of it. For the remote session to work the partner has to start a small application, which does not require installation or administrative rights.
Drupal is a popular content management system (CMS) used to run some of the largest blogs and websites across the internet. Due to the stability of the base, the adaptability of the platform, and its active community, Drupal remains a popular choice after more than a decade on the scene.
Before we get the Drupal site and install them into our web directory, we need to prepare our system. We need to install Apache, PHP, and MySQL and we need to make some additional changes to each of these for our installation.
Here below I am going describe the steps that how to host a drupal site having Amazon EC2 instance and having Amazon RDS for DB host. Continue reading
A process is a running instance of a launched, executable program. So being a System Engineer it is not easy to monitor Linux server/system performances and keep them up and running, here in this post i will cover mostly used command line to monitoring that might be useful for those who are taking care of Linux servers/systems as Linux Administrator.
Real- time Process Monitoring by ‘ top ‘:
The ‘ top ‘ command line, top program show a dynamic view of system processes and displaying a summary or it is used to dipslay all the running and active real-time processes in ordered list. It display CPU usage, Memory usage, Swap Memory, Cache Size, Buffer Size, Process PID, User, Commands and much more. It also shows high memory and cpu utilization of a running processess. And ‘ top ‘ command continuously refreshes at a configurable interval and provides above summary in a column view. The top command is more useful for system administrator to monitor and take correct action when required. Continue reading
How to access Amazon S3 BY command line
Amazon S3 is stand for Simple storage service that is storage for the Internet. It as a, “simple storage service that offers software developers a highly-scalable, reliable, and low-latency data storage infrastructure at very low costs”.
Amazon S3 provides a simple web service interface which you can use to store and retrieve any amount of data, at any time, from anywhere on the web. Using this web service, developers can easily build applications that make use of Internet storage.
Here below i will describe how to access Amazon S3 cloud storage from the command line in Linux Step by step you can learn and execute.
One of the most popular Amazon S3 command line clients is s3cmd, which is written in python. As a simple AWS S3 command line tool, s3cmd is ideal to use when you want to run scripted cron jobs such as daily backups. Continue reading
Amazon Elastic Block Storage
EBS is a virtualized SAN or storage area network. Elastic Block Store (Amazon EBS) provides persistence block level storage volumes for use with EC2 instances. EBS volumes are highly available and reliable storage volumes that can be attached to any running instance that is in the same Availability Zone.
With Amazon EBS, you pay only for what you use. For more information about Amazon EBS pricing, see the Projecting Costs section of the Amazon Elastic Block Store page.
EBS volumes are built on replicated back end storage, so that the failure of a single component will not cause data loss. The EBS product was introduced to the general public by Amazon in August 2008 Continue reading
TOP AWS DevOps’s Questions
If you’re cloud engineer, specially someone who knows Amazon Web Services (AWS) you’ll want to have a bunch of questions to ask them to share their knowledge. As with any AWS DevOps interview.
what is VPC ?
A virtual private cloud (VPC) is a virtual network dedicated to your AWS account. You can configure or create your VPC as per requirement like select region, create subnets (IP- CIDR), configure route tables, security groups, Internet gateway etc to your AWS account By which you can launch your AWS resources, such as Amazon EC2, RDS instances etc, into your VPC. Continue reading
In a general terms Cloud Computing provides us means of accessing the applications as utilities over the Internet, or we can say that it is for anything that involves delivering hosted services over the internet.
Cloud: The term Cloud it refers to a Network or Internet In other words, we can say that Cloud is something, which is present at remote location. Cloud can provide services over public and private networks, i.e., WAN, LAN or VPN. Applications such as e-mail, web conferencing, etc.
Cloud Computing refers to manipulating, configuring, and accessing the hardware and software resources remotely. It offers online data storage, infrastructure, and application. It allows us to create, configure, and customize the applications within minimum time at low cost.
Hence, the coud Computing is making our business applications mobile and collaborative. Continue reading