Protocol not supported error on plugin redirecting to HTTPS target

[victoranaylton]

Hello All,

I have a plugin that overrides the target URL for one set in the plugin configuration.

On this plugin, i'm changing the req.targetHostname and req.targetPath and, if the target protocol is https, i'm also changing the req.targetSecure to true and the req.targetPort to 443

req.targetHostname = targetPathHostname // new target hostname
req.targetPath = targetPath // new target path

if (targetPathProtocol === 'https') {
  req.targetSecure = true
  req.targetPort = 443
} 

With this, when the request is executed, i'm getting the following error:

curl -i http://localhost:8000/health
HTTP/1.1 500 Internal Server Error
Date: Wed, 24 May 2017 12:57:14 GMT
Connection: keep-alive
Content-Length: 67

{"message":"Protocol \"https:\" not supported. Expected \"http:\""}

Just to be sure, i've configured my edgemicro instance to work with ssl but the error was the same:

curl -i https://localhost:8000/health
HTTP/1.1 500 Internal Server Error
Date: Wed, 24 May 2017 12:57:14 GMT
Connection: keep-alive
Content-Length: 67

{"message":"Protocol \"https:\" not supported. Expected \"http:\""}

Is it possible to do this? Change the target URL and also change from HTTP to HTTPS?

I'm using the following versions:

current nodejs version is v6.10.0
current edgemicro version is 2.4.5-beta

[mdobson]

While it is possible to do this. It's not recommended. Here is one of two ways to make this work.

Set the target for your proxy to be an https proxy in edge. This will correctly configure everything internally.

You can also attempt to replace the agent used to make requests. You simply create an instance of https.Agent and assign it as the proxy agent. Brief code snippet below to document how to possibly do this.

var https = require('https');

//...elided 
onrequest: function(req, res, next) {
  var agent = new https.Agent({
    keepAlive: true
  })

  res.proxy.agent = agent;
//...elided
}

[victoranaylton]

Just to add more information
Found this debugging the execution:

In the plugins-middleware.js

const proxy = sourceResponse.proxy; // get the proxy from sourceResponse

...  

var httpLibrary = http;
if (sourceRequest.targetSecure || proxy.secureHttpProxy) {
  httpLibrary = https; 
}
// As the plugin sets the targetSecure to "true", the httpLibrary will be "https"

var targetRequestOptions = {
  hostname: sourceRequest.targetHostname,
  port: parseInt(sourceRequest.targetPort),
  path: sourceRequest.targetPath,
  method: sourceRequest.method,
  headers: target_headers, 
  agent: proxy.agent // this agent has a "protocol" property with "http" as value
};

...

const targetRequest = httpLibrary.request(targetRequestOptions,
  (targetResponse) => cb(null, targetResponse)); // execute the request passing the targetRequestOptions above

the execution will land in the following code in the _http_client.js file

 var protocol = options.protocol || defaultAgent.protocol; // protocol will be "https"
 var expectedProtocol = defaultAgent.protocol;
 if (self.agent && self.agent.protocol) // self.agent is the same targetRequestOptions.agent
    expectedProtocol = self.agent.protocol; // expectedProtocol will be set to "http"

  if (options.path && / /.test(options.path)) {
    throw new TypeError('Request path contains unescaped characters');
  } else if (protocol !== expectedProtocol) { //this will be true:  Error!!
    throw new Error('Protocol "' + protocol + '" not supported. ' +
                    'Expected "' + expectedProtocol + '"');
  }

[victoranaylton]

@mdobson Thanks for the answer!
I'll try as you suggested.

[victoranaylton]

@mdobson It worked as you said, sorry about the delay and thank you again!

[mdobson]

Great. One small change. You'll want to create an https.Agent outside of the onrequest function, or you'll get some performance issues down the line.

var https = require('https');
var agent = new https.Agent({
  keepAlive: true
})
//...elided 
onrequest: function(req, res, next) {
  res.proxy.agent = agent;
//...elided
}

[victoranaylton]

Great! thanks for the tip!

[asnowfix]

@mdobson is this issue addressed by https://github.com/apigee-internal/microgateway/releases/tag/v2.4.6-beta or should we still use that tiop?

[mdobson]

Still need to use the above.