Few things are more confusing than vague tech-related jargon. When it comes to DevOps, the phrases Continuous Integration, Continuous Delivery, and Continuous Deployment might well take the cake. It might well be easy to get these similar ideas confused with one another, given some of the basic definitions for each floating around…
- Continuous Integration basically just means that the developer’s working copies are synchronized with a shared mainline several times a day.
- Continuous Delivery is described as the logical evolution of continuous integration: Always be able to put a product into production.
- Continuous Deployment is described as the logical next step after continuous delivery: Automatically deploy the product into production whenever it passes QA.
Nebulous descriptions like that make it easy to think the degree of separation between these concepts is inconsequential. Those subtle distinctions make knowing the differences worthwhile, however. In this post, we’re going to cover the meanings of these terms in greater detail, along with what makes each unique and how their variances matter.
When practicing Continuous Integration, developers will frequently merge their changes back into the main branch of a shared cache. Instead of building separate features in isolation and incorporating those individual changes into software at the end of a development cycle, multiple developers will integrate their code to the mainline several times throughout their day (under ideal circumstances).
Using a build server specifically designed for automated testing, the changes are put through their paces to catch potential conflicts early on, avoiding the so-called “integration hell” that might occur when attempting to integrate changes mere days before a product is due to release.
Circumventing a situation where software might work on an individual developer’s machine but fails when combined with the code from other developers who are working on different parts of the same project is a boon in and of itself. The benefits, however, go beyond that.
Using a strategy of Continuous Integration can also boost the productivity of individual developers. As they produce code, it is integrated and tested with other developer’s code. By gaining immediate feedback on code and integration errors, they can respond to problems quickly, making necessary corrections before they become larger issues and keeping them in a near-continuous state of progress.
These potential benefits, however, are only a net positive when combined with a degree of automation, however. Simply integrating code does not guarantee a superior product. Those changes must be tested to ensure proper functionality. When organizations use manual methods to ascertain if new code is introducing bugs, tampering with operations, and, in general, is up to standards, Continuous Integration can put a strain on time and resources.
By making use of automation and test suites, the process becomes much more feasible. Instead of manually running the required tests, developers can upload code, then automated processes will handle creating a new software build and testing it for integration errors. Should any problems arise, the dev team will be alerted, allowing them to move swiftly to correct complications before proceeding.
In the end, the idea is to make integration a simple, routine process rather than a nightmare that occurs near the end of a development cycle. The team has the ability to correct programming defects early on, and the overall costs of integration are, as a result, reduced.