Continuous delivery is an extension of continuous integration since it automatically deploys all code changes to the testing and production environment after the build stage.
This means that you have an automated release process on top of automated testing, and you can deploy your application any time by clicking a button.
In theory, you can decide to release daily, weekly, fortnightly, or whatever suits your business requirements with continuous delivery. However, suppose you truly want to get the benefits of continuous delivery. In that case, you should deploy to production as early as possible to make sure that you release small batches that are easy to troubleshoot in case of a problem.
Generally, continuous delivery is an approach to software engineering based on producing software in short cycles. By developing in short cycles, teams can reliably release their software at any time.
Development teams can build, test, and release software faster and more frequently with a continuous delivery process. As a result, they can reduce the cost, time, and risk of delivering each change. Therefore, a repeatable deployment process is important for continuous delivery.
In continuous delivery, which can be looked at as an extension of continuous integration, “developers frequently hand off new code to the quality assurance (QA) and operations teams for testing,” as described by TechTarget.
Continuous delivery is the second part of continuous integration / continuous delivery, or CI/CD, a practice that enables application development teams to release incremental code changes to production quickly and regularly.
Continuous delivery process benefits
- Low-risk releases – The primary goal of continuous delivery is to make software deployments painless, low-risk events that can run at any time, on-demand. Applying patterns such as blue-green deployments is relatively straightforward to achieve zero-downtime deployments that are undetectable to users.
- Faster time to market – It’s not uncommon for the integration and test/fix phase of the traditional phased software delivery lifecycle to consume weeks or even months. When teams work together to automate the build and deployment, environment provisioning, and regression testing processes, developers can incorporate integration and regression testing into their daily work and completely remove these phases. We also avoid the large amounts of re-work that plague the phased approach.
- Higher quality – When developers have automated tools that discover regressions within minutes, teams are freed to focus on user research and higher-level testing activities such as exploratory testing, usability testing, and performance and security testing. Building a deployment pipeline can perform these activities continuously throughout the delivery process, ensuring quality is built into products and services from the beginning.
- Lower costs – Any successful software product or service will evolve significantly for its lifetime. By investing in build, test, deployment, and environment automation, we substantially reduce the cost of making and delivering incremental changes to software by eliminating many of the fixed costs associated with the release process.