Odd behaviour when connecting to an https backend

[craigedmunds]

I'm attempting to create a proxy to an https API that sits behind Cloudflare:

http.createServer(yakbak('https://--domain--', {
dirname: __dirname + '/tapes'
})).listen(3000);

When I do this, and curl the proxy:

curl -i localhost:3000/status

I get an error from cloudflare "The request's Host header does not match the request's TLS SNI Host header."

I've got a code change for the proxy to fix this; updating the headers collection prior to mod.request rather than using preq.setHeader('Host', uri.host), and this fixes it, but wasn't able to reproduce it with a test.