Add golang-version datasource

[rarkins]

What would you like Renovate to be able to do?

Support a datasource that returns all available versions of golang.

Did you already have any implementation ideas?

I haven't found a list of releases on golang.org that seems semantic enough to "scrape". e.g. this is an example from the release history:

We could instead use https://github.com/golang/go/tags although there's a risk that tags will appear there before they are actually available for download.

Alternatively, we could use the official golang image tags on Docker Hub even though they probably get built last, as this would be the safest. So we'd query for golang on Docker Hub and then filter for any matching go1.X or go1.X.Y (i.e. no suffix) and then strip the go prefix.

[rarkins]

@viceice I think it would be good to have an explicit golang-version datasource even if it's a wrapper for a Docker Hub lookup - what do you think? This would then allow us to update the version of go within go.mod.

[viceice]

We use the docker tags as source for our golang docker images
https://github.com/renovatebot/docker-go/blob/master/Dockerfile#L1

[olegkrivtsov]

I'd like to take this one.

[olegkrivtsov]

My plan for implementing this is the following:

1. Add a new datasource to lib/datasource/golang-version. Maybe use the ruby-version datasource as a base (it seems that datasource is very similar to what needs to be implemented).
2. Use https://go.dev/dl/ as the URL to scrape. As far as I can see, this HTML page can be parsed/scraped with regexes and golang versions can be extracted.

I've also checked Docker Hub https://hub.docker.com/_/golang?tab=tags, but this page is rather similar to go.dev, so I would try to parse go.dev if you feel OK about that.

[viceice]

Can you check if they also publish some JSON or yaml files? So we don't need those Regex stuff.

[rarkins]

We also want to make sure that we don't propose upgrades to people before the downloads are ready. @viceice This is maybe a chicken and egg problem if we want to use this datasource ourselves for building go images but also if we were to send people PRs which rely on our images being ready already.

[viceice]

yes, currently we use the golang docker images, so we're pretty sure all builds are ready.

here's the source for the release list: https://github.com/golang/website/blob/master/internal/history/release.go

[olegkrivtsov]

Thanks @viceice, so my plan would be to use the URL https://github.com/golang/website/blob/master/internal/history/release.go you provided to extract versions.

I tried to find a json or yaml file with go versions, but no luck.

[renovate-release]

🎉 This issue has been resolved in version 31.64.0 🎉

The release is available on:

• GitHub release
• 31.64.0

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