feat: implement proxy support

[rozenmd]

Closes #988

[changeset-bot]

🦋 Changeset detected

Latest commit: 4826964

The changes in this PR will be included in the next version bump.

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wrangler	Patch

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[github-actions]

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[petebacondarwin]

Nice simple fix! Approving with a request and a question.

Could you add a bit of explanation to the changeset of how this fixes the problem? Something like, configures the undici library to send all requests via a proxy selected from the first non-empty environment variable from "https_proxy", "HTTPS_PROXY", "http_proxy" and "HTTP_PROXY".

I wonder if we could add a test for this? Since we mock out fetch in our unit tests, I don't think it is possible there...

[rozenmd]

Thanks @petebacondarwin, I've updated the changeset.

Also yeah, not entirely sure how we'd test this, still trying to work that out.

[threepointone]

It's fine if we don't write this test I think. If we had to, we'd make another fixture app under /examples and set it up there, but it would be slow and not much return for the effort.

But yay excited to unblock people behind corporate proxies!

Did you have a look at proxy.ts? I think we may have to do stuff there too. It's fine if it's in a follow up PR.

[petebacondarwin]

Good spot @threepointone - I think we do need to fix up to work with a proxy:

    const remote = connect(`https://${previewToken.host}`);

It might be worth creating a manual one-off test setup with a proxy (blocking direct access to CF - if that is not ridiculously hard to do??); and then run through all the Wrangler commands to check we haven't missed anything.

[threepointone]

Huh that's weird, I thought we were already at 5. Damn, nice catch.

[rozenmd]

Closing this PR as I keep finding problems while testing, and I don't want to accidentally merge it.

[rozenmd]

Waiting until nodejs/undici#1451 gets released before we can land this PR.

[rozenmd]

Confirming that undici v5.3.0 (https://github.com/nodejs/undici/releases/tag/v5.3.0) fixes the issues I was seeing.

Running export HTTPS_PROXY='http://localhost:8080' && wrangler dev and export HTTPS_PROXY='http://localhost:8080' && wrangler publish both now work behind a proxy as expected.