Optimize by allowing latest versions installed to be used

[x448]

Currently, using setup-go can take roughly 10 seconds.

Having setup-go update a symlink to point to a preinstalled Go should take less than 1 second. The current way of installing Go can continue to be used for versions not preinstalled.

The ubuntu-latest image lists Go 1.11, 1.12, 1.13, 1.14 in their release notes.

[x448]

If adding multiple preinstalled Go versions to ubuntu-latest or windows-latest, etc. isn't approved, maybe ubuntu-latest-go or windows-latest-go has a better shot at getting approved?

This would be useful for any language that releases often (like Rust, having ubuntu-latest-rust).

[bryanmacfarlane]

We don't even need to do the symlink approach. image generation just needs to have more versions pre-installed in the cache layout. If that's done, it will be instant for the version hits (common ones on the image) and only take the 10 second hit if it's a miss.

Also, if you want to use the preinstalled go, then just don't use setup-go action and that one will be in your path. Be aware - that one slides on you as new versions come out.

[bryanmacfarlane]

If adding multiple preinstalled Go versions to ubuntu-latest or windows-latest, etc. isn't approved

Do you have an issue number?

[x448]

If adding multiple preinstalled Go versions to ubuntu-latest or windows-latest, etc. isn't approved

Do you have an issue number?

Nope, this is the only issue I opened with GitHub. I didn't know if better approaches were available to setup-go behind the scenes.

[tjanez]

Also, if you want to use the preinstalled go, then just don't use setup-go action and that one will be in your path. Be aware - that one slides on you as new versions come out.

I think that's the main reason why one would want to use the setup-go action rather than just use whatever Go version is in the PATH, namely to prevent breaking CI when a new version, e.g. Go 1.14, is released.

But as @x448 said, the performance penalty, especially for quick workflows, of 10s vs. 1s without setup-go is a quite big.

[tjanez]

Ouch, I just discovered that, e.g. Ubuntu 18.04 image, defaults to Go 1.12 (while also having Go 1.11 and Go 1.13 pre-installed) despite Go 1.13 being out since Sep 3, 2019.

Furthermore, all minor revisions of installed Go versions are out-dated:

• Go 1.11 (installed version: 1.11.12, latest version: 1.11.13)
• Go 1.12 (installed version: 1.12.7, latest version: 1.12.17)
• Go 1.13 (installed version: 1.13, latest version: 1.13.8)

All never minor releases of the respective Go versions contain fixes for security vulnerabilities, so this is also a security issue.

So, currently, using setup-go is basically a necessity.

[x448]

@bryanmacfarlane on March 16, actions/virtual-environments released ubuntu image with latest version of each of the last 4 big releases of Go (1.11.x to 1.14.x).

It would be great if actions/setup-go can leverage this to eliminate the 10 second lag.

Ubuntu 1804 (20200316 update) released by actions/virtual-environments lists:

• Go 1.11 (go version go1.11.13 linux/amd64)
• Go 1.12 (go version go1.12.17 linux/amd64)
• Go 1.13 (go version go1.13.8 linux/amd64)
• Go 1.14 (go version go1.14 linux/amd64)

BTW, the release notes for Windows Server 2019 image (released on March 19) only mentions
Go 1.14.

[bryanmacfarlane]

The correct fix to cut out the 10s is for image gen to populate the cache with n - x latest versions.

[ydnar]

A related issue: if you don’t specify go-version, can it just default to the latest version?

Currently, it silently short-circuits and doesn’t add $GOBIN to $PATH, which seems…wrong.