Caching files between GitHub Action executions

[hugovk]

Is the artifact unique per branch and PR, as it is with Travis caches?

https://docs.travis-ci.com/user/caching/ says:

• Travis CI fetches the cache for every build, including branches and pull requests.
• If a branch does not have its own cache, Travis CI fetches the cache of the repository’s default branch.
• There is one cache per branch and language version/ compiler version/ JDK version/ Gemfile location/ etc.
• Only modifications made to the cached directories from normal pushes are stored.

[mark-rushakoff]

Based on the terse conversation at https://github.com/actions/download-artifact/issues/3, it looks like download-artifact is not a solution to caching across invocations of workflows.

My use case is a project using Go, where I would like to preserve GOCACHE from one Workflow invocation to another. This particular project is taking about 11 minutes to run `go test -race ./...`. If it could use the build cache from a previous run, I would expect it to take less than a minute, as many of the test results would be cached and most of the compilation results would be cached too.

Not being able to transfer GOCACHE between runs is a significant hindrance to adopting GitHub Actions.

[ethomson · Accepted solution]

We appreciate the feedback, it's clear to us that this is necessary.  We're working on caching packages and artifacts between workflow executions, we'll have it by mid-November.

[miltzi]

That's great to hear! We weren't comfortable moving over from Circle without this.

Looking forward to it.

[daviseford]

Awesome! Thanks :)

[cemo]

We are also waiting this to move completely. <3

[sr229]

Glad you guys are working on this as well, I use GitHub Actions to build some intermediary packages and caching is the only way to do it since artifacts won't really cut it for large objects. It'd take too long to upload.

[croaky]

Looking forward to it! My use case:

On a macOS instance, cache some Node global dependencies `expo-cli`, `react-native`, and ` @sentry/cli`. Possibly also some CocoaPods.

[wouterds]

That's cool man, just got accepted in the beta and really loving it!

When this is live I might get rid of CircleCI all together 😄!

[tuler]

For those who can't wait the official cache solution, implementing one is not that hard.

You need an external storage. I used an S3 bucket for that.

Do a `aws s3 sync <remote> <local>` before the build, then a `aws s3 sync <local> <remote>` after the build.

Build must be smart enough to use the files you download from remote location.

It's working well for me.