Add Vercel deployment workflows (docs)

[gantoreno]

Fixes GRO-956

• Adds CI workflows for Vercel:
  • Setting up & tearing down preview environments
  • Deploying to production

[linear]

GRO-956

[github-actions]

The deployments were removed when this pull request closed. Reopening it deploys again at the same address.

[bpander]

Overall looking really good. Found only a couple blocking issues.

[bpander]

Unfortunately this causes quite a few 404s. Some links are defined in the docs source files as relative, e.g. in [metabase]/docs/README.md there's [cloud vs self-hosting](./cloud/cloud-vs-self-hosting.md).

In production, because /docs/latest/ has a trailing slash, the href resolves to /docs/latest/cloud/cloud-vs-self-hosting which is correct.

But without the trailing slash, it resolves to /docs/cloud/cloud-vs-self-hosting which 404s.

I think there are quite a few relative links. Do we actually need to force it one way or the other?

[gantoreno]

Good catch. I believe there's opportunity for consistency & unification here. I changed these settings but I believe I missed updating the Astro build format to avoid trailing slashes

My inclination would be to remove trailing slashes given that there's only 4 out of 489 URLs listed on the sitemap which end with a trailing slash, the majority seems to not have it, so maybe that's a tradeoff worth taking for consistency purposes

[gantoreno]

EDIT: I'll hold that thought, the fix wasn't quite as small as I wanted. Went with the simples which is just keeping the existing behavior in prod

[bpander]

I'm pretty sure this will leak into production since docs doesn't have a custom domain. I think you can just use pre instead though since we're just targeting PR envs, e.g.

pre: `${PROJECT_NAME}-pr-`

[gantoreno]

Oof, you're right. The underlying proxy from the production marketing deployment will still hit the .vercel.app domain

One thing I remembered we can do is request header deletion in the marketing project's vercel.ts, something like:

{
  src: "^/docs(?:/.*)?$",
  has: [{ type: "host", value: "metabase.com" }],
  transforms: [
    {
      type: "response.headers",
      op: "delete",
      target: { key: "x-robots-tag" },
    },
  ],
  continue: true,
}

Essentially handing control over to marketing, which owns the domain, "unless this app is being accessed via its intended host & path, it won't index".

The pre rule works too, I guess it's a bit too paranoid but it'll still leaves metabase-docs.vercel.app open to being indexed

[bpander]

Ah yeah I like that option more since it's simple and reasonable and it'd handle metabase-docs.vercel.app too. Good thinking.

[gantoreno]

Addressed in the marketing PR: fix: purposefully index docs if accessed via the metabase.com domain

[bpander]

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