Prevent Concurrent Branch Pipelines

[Curtis]

We are migrating an application from Bamboo to Bitbucket Pipelines. This application is unique in that it should only have one build running per branch at a time. This wasn't a problem in Bamboo, as that was the default. But in Bitbucket Pipelines, you push a 2nd commit for the same branch, it will execute another pipeline and build for the same branch.

I know Pipelines allows only one execution going per Deployment environment, but I've not seen any configuration to do this for non-deployments and per branch.

I could limit it to 1 by having a single self-hosted runner, but then only one build would happen at a time for any branch. Two different branches can build concurrently, we just can't have the same branch have a 2nd build triggered.

What is our best option to move forward with using Bitbucket Pipelines to replace Bamboo in this regard?

Thanks.

[Aron Gombas _Midori_]

I don't think that you can implement a "one build per branch" model out of the box using the built-in features.

Maybe, you could invent your own concurrency control:

1.  you maintain a short-living flag "isBuildRunning" per branch somewhere 
2. every build check this flag and only proceeds if it is FALSE
3. if it proceeds, it sets it to TRUE
4. when it completes, it sets to FALSE