Instead of releasing big bang release of features, companies are now trying to see if small features can be delivered in short and regular intervals. This enables many advantages like getting quick feedback from customers and better quality of software and higher customer satisfaction. For achieving this, there is a need for increasing the deployment frequency, reduce the failure rate of releases, reduced time gap between fixes.
Some of the popular DevOps tools:
Git - for version control system tool
Jenkins - continuous integration tool
Chef, Ansible - configuration management and deployment tools
Docker - Containerization tool
Selenium - continuous testing tool
Nagios - Continuous Monitoring tool
Developers develop the code and this source code can be managed by Version Control System tools like Git. Developers check-in this code into the Git repository and any changes made in the code is committed to this repository. Jenkins pulls this code from the Git repository using the Git plugin and build it using tools like Ant. Configuration management tools like Chef / puppet deploys & provisions testing environment and then Jenkins releases this code on the test environment on which testing is done using tools like selenium. Once the code is tested, Jenkins send it for deployment on the production server. Post deployment it is continuously monitored by tools like Nagios
Docker containers provides testing environment to test the build features.
Version control is a system that records changes to a file or set of files over time so that you can recall specific versions later. Version control systems consist of a central shared repository where team members can commit changes to a file or set of file. Git has a major advantage it has over other VCS tools like SVN is that it is a distributed version control system. Distributed VCS tools do not necessarily rely on a central server to store all the versions of a project’s files. Instead, every developer “clones” a copy of a repository and has the full history of the project on their own hard drive.Git is a Distributed Version Control system (DVCS). It can track changes to a file and allows you to revert back to any particular change. There is a central cloud repository as well where developers can commit changes and share it with other team members.
Continuous Integration (CI) is a development practice that requires developers to integrate code into a shared repository several times a day. Each check-in is then verified by an automated build, allowing teams to detect problems early.
Developers check out code into their local work spaces. Once done with code changes, they commit the changes to the Version Control Repository. CI server monitors the repository and checks out changes as and when they occur. CI server then pulls these changes and builds the system and also runs unit and integration tests. CI server will inform the team of the successful build. In case of build or tests failures, the CI server will alert the team for fixing.
Success factors for Continuous Integration would include maintaining a shared code repository, automated build, making build self-testing, everyone commits to the baseline, every commit to the baseline should be built, test in a production like environment, all team members can see the results of the latest build, automated deployment.
Usage of Jenkins for CI: move a job from one installation of Jenkins to another by simply copying the corresponding job directory. Make a copy of an existing job by making a clone of a job directory by a different name. Continuous Testing is the process of executing automated tests as part of the software delivery pipeline to obtain immediate feedback on the business risks associated with in the latest build. In this way, each build is tested continuously, allowing Development teams to get fast feedback so that they can prevent those problems from progressing to the next stage of Software delivery life-cycle. Automation testing is a process of automating the manual process to test the application/system under test. Automation testing involves use of separate testing tools which lets you create test scripts which can be executed repeatedly and doesn’t require any manual intervention.
Selenium supports two types of testing 1. Regression Testing: re-testing a code around an area where a defect was fixed. 2. Functional Testing: refers to the testing of software features individually.
Infrastructure as Code IAC is a type of IT infrastructure that operations teams can use to automatically manage and provision through code, rather than using a manual process.
Puppet is a Configuration Management tool which is used to automate administration tasks.
Puppet has a Master-Slave architecture in which the Slave has to first send a Certificate signing request to Master and Master has to sign that Certificate in order to establish a secure connection between Puppet Master and Puppet Slave. Puppet Slave sends request to Puppet Master and Puppet Master then pushes configuration on Slave
Chef is an automation platform that transforms infrastructure into code. Chef is a tool for which you write scripts that are used to automate processes.Chef Server is the central store of your infrastructure’s configuration data. Chef Server stores the data necessary to configure your nodes and provides search. Chef Node is any host that is configured using Chef-client. Chef-client runs on your nodes, contacting the Chef Server for the information necessary to configure the node. Since a Node is a machine that runs the Chef-client software, nodes are sometimes referred to as “clients”. A Chef Workstation is the host you use to modify your cookbooks and other configuration data.
Containerization: containers are used to provide consistent computing environment from a developer’s laptop to a test environment, from a staging environment into production.
Container consists of an entire runtime environment, an application, plus all its dependencies, libraries and other binaries, and configuration files needed to run it, bundled into one package. Containerizing the application platform and its dependencies removes the differences in OS distributions and underlying infrastructure.
Docker image are used to create containers. Images are created with the build command, and they’ll produce a container when started with run. Images are stored in a Docker registry because they can become quite large, images are designed to be composed of layers of other images, allowing a minimal amount of data to be sent when transferring images over the network. Docker containers include the application and all of its dependencies but share the kernel with other containers, running as isolated processes in user space on the host operating system. Docker containers are not tied to any specific infrastructure: they run on any computer, on any infrastructure, and in any cloud. Docker containers can be created by either creating a Docker image and then running it or you can use Docker images that are present on the Dockerhub. Docker containers are basically runtime instances of Docker images.
Docker hub is a cloud-based registry service which allows you to link to code repositories, build your images and test them, stores manually pushed images, and links to Docker cloud so you can deploy images to your hosts. It provides a centralized resource for container image discovery, distribution and change management, user and team collaboration, and workflow automation throughout the development pipeline.
Docker Swarn is native clustering for Docker which turns a pool of Docker hosts into a single, virtual Docker host. Docker Swarm serves the standard Docker API, any tool that already communicates with a Docker daemon can use Swarm to transparently scale to multiple hosts.
No comments:
Post a Comment