Reading Time: 6 mins.
As we all know, the Software Development Life Cycle (SDLC) comprises numerous stages both major and minor that differs from one company to another. The CI/CD pipeline is one such critical practice that helps to streamline the development process with regard to initiating code builds, performing automated tests, deploying the build to a staging and production environment. The benefit is that the automated pipelines help to remove error-prone manual steps, provide standardized development feedback loops and enable fast product iterations.
In this article, let us see the essentials of Continuous Delivery/Deployment, its difference, role and significance and benefits upon implementing it in the SDLC process.
What is Continuous Delivery?
The Continuous Delivery is one of the phases in the entire CI/CD pipeline that preps the build software in such a way that it can be deployed to production at any time. It is to deliver the build, be it features, changes, bug fixes and experimentation in a sustainable way and thereby, making it a deployment-ready software. In Continuous Delivery (CD), the aim is to always keep the code in deployable state for immediate release.
What is Continuous Deployment?
It is the follow-up of Continuous Delivery (CI), focused on validating the code quality using automated testing methods and tools. This ensures that the changes done to the codebase are correct and stable enough to perform deployment to the production environment at any given time. As known, the code mobility from one machine to another and ensuring the working status are a resource-heavy process and at times strenuous too. It is because of this reason, the deployment tools are used to automate the time consuming menial tasks and to pull the developers out of the infrastructure overhead.
Difference between Continuous Delivery and Continuous Deployment
The difference between continuous delivery and deployment lies in the fact that the stakeholders may choose not to release the software into production with continuous delivery. This happens because of various reasons despite the continuous delivery being the integral part of the SDLC process and following up the building and testing phases of the CI equal to continuous deployment.
To understand it better, let us take a glimpse of the steps involved in both the continuous delivery and continuous deployment phases.
- Each and every commit undergoes an automated build and acceptance testing.
- A follow-up of the Continuous Integration phase.
- A code in a deployable state and overall, deployment-ready software.
- It includes Blackbox and Whitebox testing.
- Similar to continuous delivery, automated build and UAT for every commit.
- It is one step further to Continuous Delivery.
- The software is continuously deployed to the production environment.
- Covers up the entire steps and procedures required to deploy the software.
Steps involved in Continuous Deployment
Prior to prepping up the software for the deployment to staging and production environment, a separate stage involving the review of code quality and stability is performed. A manual code review by the fellow team members (called peer review) also executed depending on the requirements.
Though the staging is also about practicing pre-production deployment, it is recommended to perform continuous deployment to the staging environment. This enables the readiness to validate the code at any time and the facility to fix any concerns prior to production deployment.
With the confidence that all the necessary steps are taken care of to deliver only working code, the final deployment to the production environment is executed. At the time of finding any discrepancies over the expected outcome, you can quickly revert to the stable version.
Benefits of Continuous Delivery/Deployment
- Reduced release risks
The aim here is to keep the deployment effortless and with possibly less-risk involved. This allows a faster deployment and zero-downtime by enabling methods like blue–green deployments (see, Case Study of Dixon Retail ) which in turn make the on-demand deployment possible too.
- Faster market releases
Compared to the traditional methods of software development processes, the various stages of the SDLC such as build, deployment, provisioning and testing are integrated into the daily work of developers. This works when it comes to get rid of the re-work that usually consumes a week’s or month’s time to test and fix the unsettled things.
- Quality products
The build pipeline comes to a greater rescue in identifying the little regressions that come in the way of delivering quality products to the end-consumer. Due to this the developers can happily spend their time in much higher-level testing activities such as usability testing, exploratory testing, security testing, performance testing, etc. Further, the automated build pipeline ensures the process is executed throughout the CD process.
- Reduced cost
Integration of build, test, deployment and environment automation into the daily lives of development and operations reduces the cost of making incremental changes to the software and other fixed costs come along with the release process. This is significant as be it any software which focuses on delivering quality services, needs to evolve over the course to match the user demands.
- Better software
By amplifying the feedback loops in the daily routine work of dev and ops leads to a much better quality software. The principles of continuous delivery makes the tasks done in patches, each separately built, tested and validated which in turn leads to receiving instant feedback about the delivered services. This way the business and other stakeholders can easily eliminate the features that offer zero value to the businesses.
Thus, this article walked you through the basic concepts around the terminology Continuous Delivery/Deployment (CD) such as Build Pipeline, the very difference between continuous delivery and continuous deployment, it’s benefits and the steps involved. Need a similar insight for Continuous Integration and about its workflow, go to Continuous Integration (CI) . Further, there are numerous monitoring and logging tools (known as the performance management tools) out in the market for tracking of the CI/CD pipelining such as Nagios, Splunk and so forth that focuses on business, web analytics, application management, security and compliance checks.