migrate to go 1.14 + modules

[skriss]

closes #1886
xref #2127

This PR migrates Velero from dep to go modules for dependency management, and upgrades the go version to 1.13 1.14. Heavily inspired by @ashish-amarnath's work in #2127.

Probably easiest to review commit-by-commit, as I broke it up into small steps.

I believe the only thing that's not using modules yet is the Kubernetes code-generator tool - it's still being cloned into a $GOPATH-based dir and being run from there due to some compatibility issues (I'll update with links to issues).

I've tested all of the main workflows and things seemed to be working properly, but I would definitely appreciate some further testing before getting ready to merge this.

[carlisia]

Hey @skriss I pulled this branch locally to run tests. Got some errors "not finding package" and am thinking there needs to be a go mod command run? I can google but if that's the case, should some documentation be added to the Contribute section?

[skriss]

Hey @skriss I pulled this branch locally to run tests. Got some errors "not finding package" and am thinking there needs to be a go mod command run? I can google but if that's the case, should some documentation be added to the Contribute section?

Hmm, not sure off the top of my head what issue you're running into -- can you provide some more detail (go version, is the code in $GOPATH, what's $GO111MODULE set to, what command did you run, full error output)?

[carlisia]

Nvm, all I had to do was upgrade to 1.13.

[carlisia]

This looks good to me.
Also, ran the tests using this branch and it's all good.

[skriss]

moving out of draft but I still have some followups

[nrb]

Putting this on hold so it can be moved to post-1.3.

[skriss]

rebased, addressed feedback, and updated to go 1.14. let's see if it passes CI..

[ashish-amarnath]

The CI is passing 🎉

[skriss]

I'll do a little bit of retesting on this just to ensure nothing broke with the latest changes, but I think it's good to go.

We'll hold until just after we release 1.3.

[nrb]

During my manual testing of building and running through some sample backups/restores (not with restic), this appears to work as expected. I do have a question inline, though.

[jenting]

❤️

[skriss]

I retested the CI steps as well as the local dev stuff (go build/go test locally) inside and out of $GOPATH, and everything LGTM, so from my perspective this is ready to go. I will file a couple follow-up enhancement issues as well.

[nrb]

Thanks for shepherding this through @skriss and @ashish-amarnath! Hopefully all this work will make moving the plugins over much easier.

[ashish-amarnath]

LGTM! 🚀