Override GOPATH to use Renovate cache

[rarkins]

Describe the proposed change(s).

Currently Containerbase defaults to /go for GOPATH, this means that installed Go modules accumulate there. Instead, we should be aiming for all managers to use cacheDir.

[rarkins]

Hmm:

renovate/lib/modules/manager/gomod/artifacts.ts

Line 202 in b6d2c4b

GOPATH: await ensureCacheDir('go'),

[rarkins]

This GOPATH override doesn't seem to take effect.

A new renovate/renovate container:

ubuntu@8ca7c127dcb9:/usr/src/app$ du -sh /go/*
4.0K    /go/bin
4.0K    /go/pkg
4.0K    /go/src
ubuntu@8ca7c127dc

After running on a repo where Go PRs are created:

ubuntu@344ee60b6846:/usr/src/app$ du -sh /go/*
4.0K    /go/bin
498M    /go/pkg
4.0K    /go/src

[jamietanna]

Interesting that we wire it in already - up until now I've been explicitly setting GOPATH in my container setup to override it to the cacheDir - it looks like we should be wiring that variable in correctly 🤔

[viceice]

https://github.com/containerbase/base/blob/60ada9adb2ff7b6cc5ffe97f007b8a31c6c22070/src/usr/local/containerbase/tools/v2/golang.sh#L9

this is overriding the renovate env, it will be fixed in containerbase v11