Making “Push on Green” a Reality is an insider look at how Google handles continuous deployment. Very few teams and companies need to deal with such level of complexity, but the overall principals still probably apply.
Updating production software is a process that may require dozens, if not hundreds, of steps. These include creating and testing new code, building new binaries and packages, associating the packages with a versioned release, updating the jobs in production datacenters, possibly modifying database schemata, and testing and verifying the results. There are boxes to check and approvals to seek, and the more automated the process, the easier it becomes. When releases can be made faster, it is possible to release more often, and, organizationally, one becomes less afraid to “release early, release often”. And that’s what we describe in this article—making rollouts as easy and as automated as possible. When a “green” condition is detected, we can more quickly perform a new rollout. Humans are still needed somewhere in the loop, but we strive to reduce the purely mechanical toil they need to perform.