I have been following this official documentation on how to get parallel builds running in AWS CodeBuild using a batch matrix. Right now my buildspec.yml is structured like this:
## buildspec.yml
version: 0.2
batch:
fast-fail: false
build-matrix:
dynamic:
env:
variables:
INSTANCES:
- A
WORKERS:
- 1
- 2
phases:
install:
commands:
- npm ci
build:
commands:
- npx cypress run <params>
In this example we run two parallel workers, though IRL we run 11.
This works well for one use case, where we check out the code and run the Cypress tests against the pre-defined URL of one of our test environments. However, we have another use-case where we need to build the application within the CodeBuild container, start a server on localhost, and then run the Cypress tests against that.
One option, of course, is just to build the app 11 times. However, since CodeBuild pricing is by the machine minute, I'd rather build once instead of 11 times. I also don't like the idea of technically testing 11 different builds (albeit all built off the same commit).
What I'm looking for is behavior similar to Docker's multi-stage build functionality, where you can build the app once in one environment, and then copy that artifact to 11 separate envs, where the parallel tests will then run. Is functionality like this going to be possible within CodeBuild itself, or will I have to do something like have two CodeBuild builds and upload the artifact to S3? Any and all ideas welcome.