The second part of the GitHub build uses the latest Docker Compose file:
RELEASE environment variable but not the BUILD_NUMBER variable the main Compose file usesWhen you merge in the latest file it will build images with the tag 21.05, which is the version for this release of the app.
Consumers can use 21.05 to get the current build for this release, or e.g. 21.05-39 to get a specific build:
docker pull courselabs/rng-api:21.05
docker image ls courselabs/rng-api
Those two tags are aliases of the same image now, but with the next release the 21.05 tag will advance and will be an alias of a later build.
Back to the exercises.