Allows API URL override via environment variable to support GitHub Enterprise

[retiman]

Fixes #23.

[retiman]

I bumped the version to 1.4.0 to avoid potentially breaking existing users.

[peter-evans]

There is a much simpler way to support GHE in actions. I've done the following in my own actions.

const githubUrl = process.env['GITHUB_SERVER_URL'] || 'https://github.com'

This is also how it's done in the official actions like checkout:
https://github.com/actions/checkout/blob/main/src/url-helper.ts#L22-L29

[retiman]

Thanks for the advice Peter. I can't get this to work on my end, though. I see your action is mainly working with the actions toolkit (actions/core in the case you linked); however, this action is leveraging octokit directly. The octokit/auth-app.js library delegates to octokit/endpoint.js, which hard codes api.github.com as the default baseUrl:

https://github.com/octokit/endpoint.js/blob/master/src/defaults.ts#L12

I don't see any place where auth-app.js, request.js, or endpoint.js are reading GITHUB_SERVER_URL or GITHUB_URL to override this value. Do you have any examples where github-app-token is generating a token with the appropriate environment variables set?

[peter-evans]

For overriding api.github.com to support GHE you can do this:

    const options: OctokitOptions = {}
    if (token) {
      options.auth = `${token}`
    }
    options.baseUrl = process.env['GITHUB_API_URL'] || 'https://api.github.com'
    this.octokit = new Octokit(options)

See: https://github.com/peter-evans/create-pull-request/blob/main/src/github-helper.ts#L27

[retiman]

Sure. That simplifies things.

[peter-evans]

Nice. LGTM but I'm not the maintainer 😄

[retiman]

Nice. LGTM but I'm not the maintainer 😄

Thanks for the help though :)

[peter-evans]

After looking at getOctokit in the github package I'm not sure if this change is necessary. The toolkit already includes this env var lookup for the base URL here: https://github.com/actions/toolkit/blob/f0b00fd201c7ddf14e1572a10d5fb4577c4bd6a2/packages/github/src/internal/utils.ts#L23-L25

@retiman Are you sure this action doesn't work on GHE already?

[retiman]

After looking at getOctokit in the github package I'm not sure if this change is necessary. The toolkit already includes this env var lookup for the base URL here: https://github.com/actions/toolkit/blob/f0b00fd201c7ddf14e1572a10d5fb4577c4bd6a2/packages/github/src/internal/utils.ts#L23-L25

@retiman Are you sure this action doesn't work on GHE already?

Yea, I verified it doesn't work if GITHUB_API_URL is present (verified last night based on your suggestion). If that variable is leveraged by octokit things would "just work".

The link you sent me is for the actions toolkit, where that makes more sense. The toolkit code is meant to be run in build agents and the GITHUB_API_URL is expected to be present. Octokit is a general use library, and its consumers are not necessarily running in a GHA runner so there's no guarantee that the var would be present.

[peter-evans]

@retiman Let me try and break down the route this action takes to build it's Octokit instance and you'll see that GITHUB_API_URL is already being handled.

getOctokit is called from the @actions/github package of the actions toolkit:
https://github.com/tibdex/github-app-token/blob/main/src/fetch-installation-token.ts#L17

A new GitHub is created from .utils:
https://github.com/actions/toolkit/blob/f0b00fd201c7ddf14e1572a10d5fb4577c4bd6a2/packages/github/src/github.ts#L19

GitHub is a new Octokit instance with defaults set:
https://github.com/actions/toolkit/blob/f0b00fd201c7ddf14e1572a10d5fb4577c4bd6a2/packages/github/src/utils.ts#L20-L23

defaults includes baseUrl, which requires a call to Utils.getApiBaseUrl():
https://github.com/actions/toolkit/blob/f0b00fd201c7ddf14e1572a10d5fb4577c4bd6a2/packages/github/src/utils.ts#L12-L18

getApiBaseUrl() handles GITHUB_API_URL with a fallback:
https://github.com/actions/toolkit/blob/f0b00fd201c7ddf14e1572a10d5fb4577c4bd6a2/packages/github/src/internal/utils.ts#L23-L25

You can see the code exists in the dist minified release of the action:

So the Octokit instance used by this action should already have the correct base URL set if GITHUB_API_URL is available in the environment that it's running in.

[retiman]

@peter-evans I don't deny this is happening at the actions toolkit level; all the links you gave are code paths into actions/toolkit.

However, when using a non-modified version of this action in GHE, I'm hitting the 404 error on line 15 in fetch-installation-token.ts, before it even gets to getOctokit:

https://github.com/tibdex/github-app-token/blob/main/src/fetch-installation-token.ts#L15

The createAppAuth function in octokit/auth-app.js calls octokit/request.js:

https://github.com/octokit/auth-app.js/blob/master/src/index.ts#L49
https://github.com/octokit/request.js/blob/master/src/index.ts#L7
https://github.com/octokit/request.js/blob/master/src/with-defaults.ts#L15

You'll see in octokit/endpoint.js (which is referenced from with-defaults.ts), the URL is hard coded:

https://github.com/octokit/endpoint.js/blob/master/src/index.ts#L4
https://github.com/octokit/endpoint.js/blob/master/src/defaults.ts

Stepping back a bit, do you believe that the env var should be checked in octokit?

EDIT: grammar

[peter-evans]

Ah, sorry. 🙏 I was getting confused because I didn't read the code properly and assumed this was about the octokit instance in use, but it's about the createAppAuth call. So in that case your change is necessary. LGTM!

(No I don't think GITHUB_API_URL should be checked in Octokit. As you rightly said, it's a general purpose lib.)

[peter-evans]

[retiman]

Ah, sorry. 🙏 I was getting confused because I didn't read the code properly and assumed this was about the octokit instance in use, but it's about the createAppAuth call. So in that case your change is necessary. LGTM!

(No I don't think GITHUB_API_URL should be checked in Octokit. As you rightly said, it's a general purpose lib.)

No worries, thanks for following up.

[tibdex]

Thanks, let's see how this works.

[retiman]

Thanks, let's see how this works.

Just tested against GHE; works great.