Continuous Integration

Continuous Integration (CI) is a software development practice where developers frequently integrate their work with the project's Integration branch and create a build.

Integration is the act of submitting your private work (modified code) to the common work area (the potential software solution). This is technically done by merging your private work (personal branch) with the common work area (Integration branch). Or we can say, pushing your private branch to the remote branch.

CI is necessary to bring out issues encountered during the integration as early as possible. This can be understood from the following diagram, which depicts various issues encountered during a single CI cycle.

A build failure can occur due to either an improper code or a human error while doing a build (assuming that the tasks are done manually). An integration issue can occur if the developers do not rebase their local copy of code frequently with the code on the Integration branch. A testing issue can occur if the code does not pass any of the unit or integration test cases.

In the event of an issue, the developer has to modify the code to fix it:

CI process