Proxy support is broken

[zmwangx]

Describe the bug

Proxy support was introduced in #1215, but it is currently broken.

To Reproduce

Steps to reproduce the behavior:

1. Somehow make api.netlify.com unavailable, e.g. by being on a closed network where a proxy is required. For reproduction purposes, one can force this by modifying /etc/hosts and pointing api.netlify.com to a local container / VM where we spin up a trivial HTTP server that simply stalls on any incoming request.
2. Have a proxy server set up, e.g. mitmproxy or Charles.
3. Run any command through a proxy, e.g. HTTP_PROXY=http://localhost:8888 netlify login.

At this point netlify-cli would simply stall, and if you monitor the proxy server you'll notice that no request is going through it.

Configuration

N/A.

Expected behavior

Any network request originating from netlify-cli should be proxied.

CLI Output

N/A.

Additional context

This happens because getConfig happens before the proxy is even configured (with getAgent)

cli/src/utils/command.js

Lines 46 to 57 in 7a55e98

	const cachedConfig = await this.getConfig({ cwd, state, token, ...apiUrlOpts })
	const { configPath, config, buildDir, repositoryRoot, siteInfo } = cachedConfig
	const normalizedConfig = normalizeConfig(config)
	const { flags } = this.parse(BaseCommand)
	const agent = await getAgent({
	exit: this.exit,
	httpProxy: flags.httpProxy,
	certificateFile: flags.httpProxyCertificateFilename,
	})
	const apiOpts = { ...apiUrlOpts, agent }
	const globalConfig = await getGlobalConfig()

getConfig calls resolveConfig which is @netlify/config.

cli/src/utils/command.js

Line 4 in 7a55e98

const resolveConfig = require('@netlify/config')

Looking at @netlify/config's resolveConfig: https://github.com/netlify/build/blob/6813d73a21a6c4a6b99576c5b7bc60fae5d8bac4/packages/config/src/main.js#L32-L36 we see that there are API requests made at this stage unless offline is true. These requests obviously aren't going through the proxy.

I guess to actually fully support proxies you need to add proxy support to @netlify/config as well.

---

Knowing the cause of the issue, here's a risky workaround btw: just set offline to true in src/utils/command.js:

-    const cachedConfig = await this.getConfig({ cwd, state, token, ...apiUrlOpts })
+    const cachedConfig = await this.getConfig({ cwd, state, token, offline: true, ...apiUrlOpts })

One can hot edit this directly into node_modules/netlify-cli/src/utils/command.js. (Don't complain to me if anything breaks, obviously.)

---

Related: I believe #2016 is exactly this problem.

[erezrokah]

Thanks @zmwangx, I believe this is a duplicate of #2399, but I'm closing #2399 in favor of this one since due to the more detailed description here