Dev: Allow custom headers on rewrites

[RaeesBhatti]

- Summary
DEPENDS ON: https://github.com/netlify/libredirect/pull/61
Fixes: #423

- Test plan

• Have following in your netlify.toml:

[[redirects]]
  from = "/api/*"
  to = "/.netlify/functions/:splat"
  status = 200
  headers = {X-From = "Netlify"}
[build]
  functions = "functions/"

• Have following in /functions/hello-world.js

exports.handler = function(event, context, callback) {
    callback(null, {
        statusCode: 200,
        body: JSON.stringify(event.headers),
    });
}

• Goto http://localhost:8888/api/hello-world in your browser
• Expect to see "x-from": "Netlify" in the response

- Description for the changelog

• Iterate through match.proxyHeaders and set them on request
• Make sure functions and addonsrequests are properly routed after rewriting

- A picture of a cute animal (not mandatory but encouraged)
🙈

[oscartbeaumont]

Is this PR still functioning as I just recreated the demo above and am not seeing the x-from header?

[RaeesBhatti]

@oscartbeaumont This has not been released on NPM yet. Have you tried after linking repo at this branch with npm link? Apologies for the confusion

[oscartbeaumont]

No, sorry I assumed this had been released. I tried linking the master branch (commands below) and could also not get it to work.

npm remove netlify-cli -g
git clone https://github.com/netlify/cli.git
npm link cli/ # This seems to npm install
netlify dev

[RaeesBhatti]

It seems like this also depends on a new release of netlify-redirector which is not open-source. Please wait until that is released, this comment thread will be updated when it is.

[oscartbeaumont]

Ok, thanks for your help. Do you have an estimated timeframe?

[RaeesBhatti]

@oscartbeaumont This change has been published today with the latest version of Netlify CLI.