Enable GCI linter

[jakule]

Sort all imports in a deterministic way.
GCI linter generates deterministic Go imports when run with the --run flag.
Introduced make fix-imports to make the process easier.

TODO:

• Update e ref when e PR is merged

[codingllama]

As said before, I'm happy with any deterministic formatting that machines can do and enforce for us.

Please run make fix-imports on teleport.e/ and update the reference here, otherwise it'll break.

[codingllama]

TODO:

[ ] Update e ref when e PR is merged

Update it now?

[mdwn]

I'm in, looks like a great idea!

[r0mant]

Couple of general notes:

• I would consider backporting this to at least all active release branches, otherwise backports will be a pain.
• Does this change local workflows in any way? I.e. do we need to install any extra Go tools that would auto-sort these imports or do we need to run make fix-imports each time before opening a PR?

[jakule]

Couple of general notes:

• I would consider backporting this to at least all active release branches, otherwise backports will be a pain.
  I'll do.
• Does this change local workflows in any way? I.e. do we need to install any extra Go tools that would auto-sort these imports or do we need to run make fix-imports each time before opening a PR?

@r0mant
Because we all properly sort imports the workflow won't change for anyone. According to @espadolini gopls should works fine. The result generated by gci should be very similar to what goimports -w does.

[codingllama]

Couple of general notes:

• I would consider backporting this to at least all active release branches, otherwise backports will be a pain.
  I'll do.
• Does this change local workflows in any way? I.e. do we need to install any extra Go tools that would auto-sort these imports or do we need to run make fix-imports each time before opening a PR?

@r0mant Because we all properly sort imports the workflow won't change for anyone. According to @espadolini gopls should works fine. The result generated by gci should be very similar to what goimports -w does.

gopls keeps existing import blocks by default, so it's not much noise. Without any extra configuration you'll likely have to move an import here and there. VSCode/gopls setup should be something like this (caveat, I don't use this):

"gopls": {
    "formatting.local": "github.com/gravitational/teleport",
    "formatting.gofumpt": true, // optional
},

[espadolini]

It gets a little weird with block comments between imports, but single-line comments after the import are fine and as long as the file is already correct with only 3 blocks of imports (standard, nonlocal, local), gopls with those settings should keep it correct according to gci.

[codingllama]

If you want to play around with, or just reformat select files, the equivalent invocation to the config is something like this:

gci write -s 'standard,default,prefix(github.com/gravitational/teleport),blank,dot' --skip-generated **/*.go

(Install to GOPATH using go install github.com/daixiang0/gci@latest.)

[github-actions]

@jakule See the table below for backport results.

Branch	Result
branch/v10	Failed
branch/v11	Failed
branch/v9	Failed