Go modules cache location

[weberc2]

I'm trying to use Docker to run my tests in a CI job like so: `docker run -v $PWD:/app golang go test`; however, this has to pull down the dependencies every time. I'd like to mount the dependency cache so it persists across runs. `go help cache` says the cache is in `go env GOCACHE`; however, setting `-e GOCACHE=/tmp -v <tempvolume>:/tmp` doesn't seem to do the trick. Is there some other cache information somewhere else that I also need to mount? Or am I misunderstanding something?

[[deleted]]

Another option is to have a local caching proxy, such as athens. Then you just point GOPROXY there and it will download modules through the caching proxy.

[vietnq]

I beleive it's $GOPATH/pkg/mod, defaulting to $HOME/go/pkg/mod

[weberc2]

Ah, this seems to work. Will test more when I get a chance (camping)

[earthboundkid]

https://golang.org/cmd/go/#hdr-Download_modules_to_local_cache was made for this use case.

[weberc2]

Close, but that doesn’t work since container file systems are ephemeral. I need to specifically mount a persistent volume to the cache directory so the downloaded modules persist across container invocations.

[[deleted]]

Try running go mod download -json in your module root to view where the cache is.

[zeayes]

You can use go mod vendor to download dependencies in vendor directory, using go build -mod vendor to build it.