´Error: listen EADDRINUSE` when proxying https

[dbuezas]

My code looks like this:

fs = require 'fs'
path = require 'path'
findFreePort = require 'find-free-port'
filternet = require('filternet')
pem = require('pem')
PROXY_PORT = null
findFreePort 8090, (err, freePort) ->
  PROXY_PORT = freePort
  pem.createCertificate {days:1, selfSigned:true}, (err, keys)->
    return console.error err if err?
    key = path.resolve 'cert.key'
    crt = path.resolve 'cert.crt'
    fs.writeFileSync key, keys.serviceKey
    fs.writeFileSync crt, keys.certificate

    sslCerts = {
      '*': [key, crt]
    }
    myProxy = filternet.createProxyServer
      port: PROXY_PORT
      transSslPort: 8129
      sslCerts: sslCerts

    myProxy.on 'interceptResponseHeaders', (request_info, response_status_code, response_headers, callback) ->
      response_headers['Content-Security-Policy'] = ''
      callback response_status_code, response_headers

and I get the following exception:

Error: listen EADDRINUSE
  at errnoException (net.js:905:11)
  at Server._listen2 (net.js:1024:19)
  at listen (net.js:1065:10)
  at Server.listen (net.js:1133:5)
  at Object.module.exports.createProxyServer (/Users/davidbuezas/shopco/awesome-phantom-node/node_modules/filternet/lib/proxy.js:306:21) Error: listen EADDRINUSE
  at errnoException (net.js:905:11)
  at Server._listen2 (net.js:1024:19)
  at listen (net.js:1065:10)
  at Server.listen (net.js:1133:5)
  at Object.module.exports.createProxyServer (/Users/davidbuezas/shopco/awesome-phantom-node/node_modules/filternet/lib/proxy.js:306:21)

What am I doing wrong?

[dbuezas]

[PARTIALLY SOLVED]
by setting sslSockDir: somePath and deleting it before the second start.
But the proxy still doesn't work, the request gets rejected.