build: update yarn to v1.16.0

[devversion]

Currently our version of Yarn is installed through the "angular/ngcontainer"
docker image. This is problematic because in order to be able to update
Yarn, we always need to update the docker image to a version that comes
with the desired Yarn version. Sometimes there is no docker image with the
desired latest Yarn version, and therefore we cannot easily update the Yarn version.

Additionally the latest Yarn versions contain various fixes for debugging timeout
issues (e.g. yarnpkg/yarn@024e9fe) and also have improved logic for restoring existing
node_modules. This is essential to take advantage of the CircleCI caching mechanism.

[jelbourn]

@alexeagle should there just be a newer version of ngcontainer?

[devversion]

@jelbourn And that's part of the problem. It makes us dependent on a docker image that doesn't have a well-defined release process. e.g. no images for latest Bazel version etc.

Additionally IMO the ultimate goal is to only bring in Bazel through one of the official gcr.io docker images (which are automated & maintained) and everything else is hermetically brought in by Bazel (e.g. Yarn / NodeJS etc.)

This right now just gives us flexibility and decouples the Yarn version from the ngcontainer image. We did the same on angular/angular upon request from dev-infra. See: angular/angular@8d11627

[jelbourn]

My concern is that we're adding extra overhead to the CI that should be captured by the container, even at the cost of some convenience

[devversion]

Hmm. I see that point and would personally also prefer not installing it dynamically as Yarn can be provided by a docker image 😄 though we are currently in a weird state where we have different types of tasks:

1. Tasks using Bazel
2. Tasks using Bazel + Yarn
3. Tasks using Yarn

Ideally we'd have one bazel image from gcr.io and one which comes with the appropriate Yarn & NodeJS version, but due to (2) we currently need a docker image that provides both. Also it's planned to remove ngcontainer according to: https://github.com/angular/angular/blob/master/.circleci/config.yml#L754 and https://github.com/angular/angular/tree/master/tools/ngcontainer#ngcontainer.

Another option would be to just use Bazel from Yarn, but it would feel more hermetic if there would be no global NodeJS / Yarn installation at all. Just a plain bazel image to guarantee hermetic behavior.

[alexeagle]

I think you should check in yarn.js in the repo like we did for angular/angular and stop treating it like software that has to be installed on the computer.

[devversion]

That would work too. I don't feel too strong about it. Happy to do whatever you all prefer 😄 I just want to get us to a more recent Yarn version since the current one does not seem to restore the cache properly and big packages like @bazel/bazel or @bazel/buildifier cause flaky CI timeouts (e.g. see here)

[jelbourn]

LGTM, I guess, if we don't have the resources to maintain the docker container

[angular-automatic-lock-bot]

This issue has been automatically locked due to inactivity.
Please file a new issue if you are encountering a similar or related problem.

Read more about our automatic conversation locking policy.

_{This action has been performed automatically by a bot.}