Support fetching Deno from GitHub releases or a custom url

[sebdanielsson]

On corporate networks it would be greatly appreciated if setup-deno could fetch the binaries from GitHub Releases (github.com) or if we could point to a custom url.

[tcely]

Having just looked over install.ts it currently does use github.com.

setup-deno/src/install.ts

Lines 23 to 36 in 390061a

	switch (version.kind) {
	case "canary":
	url = `https://dl.deno.land/canary/${version.version}/${zip}`;
	break;
	case "rc":
	url = `https://dl.deno.land/release/v${version.version}/${zip}`;
	break;
	case "stable":
	case "lts":
	url =
	`https://github.com/denoland/deno/releases/download/v${version.version}/${zip}`;
	break;
	}

[sebdanielsson]

Looks like it's resolving versions from Denoland stil:

https://github.com/denoland/setup-deno/blob/main/dist/main.mjs

[tcely]

If you mean the text files containing which is the latest version, then those are indeed being fetched from dl.deno.land, or deno.com for a list of versions.

Is this issue about avoiding accessing those sites at all?

[sebdanielsson]

Yes. In a locked down environment where we can basically only access internal stuff and GitHub.

[tcely]

Alright. I don't know of an easy replacement for the versions list, but letting people who can only access GitHub install the latest stable version is an easy adjustment.

[sebdanielsson]

Retreiving latest, stable and LTS versions from GitHub would cover all of our potential use-cases👍

[tcely]

I looked into how the latest LTS file is generated. It doesn't appear to be stored anywhere at GitHub. As long as you can learn which version it is, the latest stable should be able to retrieve that version from GitHub for you, using deno upgrade.

We will need to verify that nothing else is required during that process.

It looks like a version provided on the command line has no additional requirements, and there is a way to use a custom URL to retrieve the text files.

DENO_DONT_USE_INTERNAL_BASE_UPGRADE_URL

https://github.com/denoland/deno/blob/f01347e771191b0aa486e9a057c981d933c3f861/cli/tools/upgrade.rs#L851-L911