Skip to main content

Put mymove outside of standard GOPATH

NOTE: This ADR updates and supersedes ADR0003 Go Path and Project Layout.

MilMove adopted using the go module system as introduction in go1.12 in PR 1932. This gave us the option of continuing to host our repository inside of $GOPATH or outside of $GOPATH and per ADR0003 Go Path and Project Layout the decision was to stay in $GOPATH and set the environment variable GO111MODULE=on as a way of forcing go module behavior.

This choice had implications for other tools that the project uses like pre-commit hooks that use golang libraries. As seen in PR 2236 the interaction made it impossible to develop the project and thus people set GO111MODULE=auto and were asked to move their repository outside of $GOPATH. This also brings the local development inline with our CI/CD pipeline choices as modified in PR 2172.

Considered Alternatives​

  • Maintain direction of ADR0003 and keep repository checkout inside $GOPATH with GO111MODULE=on
  • Move repository outside of $GOPATH with GO111MODULE=auto

Decision Outcome​

  • Move repository outside of $GOPATH and explicitly set GO111MODULE=auto.
  • Falls inline with best practices for golang going forward while allowing compatibility with dependencies not ready for go modules
  • Forces everyone to move their directories or be unable to develop.

Pros and Cons of the Alternatives​

Maintain direction of ADR0003 and keep repository checkout inside $GOPATH with GO111MODULE=on​

Inside of GOPATH it is necessary to set GO111MODULE=on to force go module support. One example where this causes issues is that pre-commit is not installing its hooks into the $GOPATH but instead into ~/.cache/pre-commit. The effect is that golang modules installed by pre-commit think that they are inside of $GOPATH when they are not and that causes bad interaction issues with the tool itself.

  • + No changes needed to repository location
  • - Installation of pre-commit hooks that use golang will fail if GO111MODULE=on is set in the environment
  • - Golang dependencies need to be ready to use go modules or installation doesn't work
  • - Not in line with CI/CD setup which does not uses auto mode

Move repository outside of $GOPATH with GO111MODULE=auto​

Outside of the GOPATH it is not necessary to set GO111MODULE=auto as it is the default. However, being explicit is better than implicit and .envrc will override whatever developers set globally in their environments.

  • + Installation of pre-commit hooks that use golang will not fail
  • + Installation of dependencies that do not support go modules will not fail
  • + Prepared for future roll out of go1.13 and future changes
  • + In line with CI/CD setup which does not uses auto mode
  • - Must change repository location outside of $GOPATH

Resources​