HttpProxy

Simple multi HTTP Proxy using Plug. And support record/play requests.

MY GOAL

• Record/Play proxied requests
  • http_proxy support multi port and multi urls on one execution command mix proxy.
• Support VCR

architecture

           http_proxy
Client  (server  client)  proxied_server
  |            |            |
  | 1.request  |            |
  |  ------>   | 2.request  |
  |            |  ------>   |
  |            |            |
  |            | 3.response |
  | 4.response |  <------   |
  |  <------   |            |
  |            |            |

1. The client sends a request to http_proxy, then the http_proxy works as a proxy server.
2. When the http_proxy receives the request from the client, then the http_proxy sends the request to a proxied server, e.g. http://google.com, as a client.
3. The http_proxy receives responses from the proxied_server, then the http_proxy sets the response into its response to the client.
4. The Client receives responses from the http_proxy.

Quick use as http proxy

requirement

• Elixir over 1.7

set application and deps

• mix.exs
  • :logger is option.
  • :http_proxy is not need if you run http_proxy with HttpProxy.start/0 or HttpProxy.stop/0 manually.

def application do
  [applications: [:logger, :http_proxy]]
end
...
defp deps do
  [
    {:http_proxy, "~> 1.4.0"}
  ]
end

set configuration

• config/config.exs

use Mix.Config
config :http_proxy,
  proxies: [
             %{port: 8080,
               to:   "http://google.com"},
             %{port: 8081,
               to:   "http://yahoo.com"}
            ]

• To manage logger, you should define logger settings like the following.

config :logger, :console,
  level: :info

solve deps and run a server

$ mix deps.get
$ mix clean
$ mix run --no-halt # start proxy server

If you would like to start production mode, you should run with MIX_ENV=prod like the following command.

$ MIX_ENV=prod mix run --no-halt

launch browser

Launch browser and open http://localhost:8080 or http://localhost:8081.
Then, http://localhost:8080 redirect to http://google.com and http://localhost:8081 do to http://yahoo.com.

Development

• Copy pre-commit hook
  • cp hooks/pre-commit ./git/hooks/pre-commit

Configuration

Customize proxy port

• You can customize a proxy port. For example, if you change a waiting port from 8080 to 4000, then you can access to http://google.com via http://localhost:4000.

use Mix.Config
config :http_proxy,
  proxies: [
             %{port: 4000,
               to:   "http://google.com"},
             %{port: 8081,
               to:   "http://yahoo.com"}
            ]

Add proxy

• You can add a waiting ports in configuration file. For example, the following setting allow you to access to http://apple.com via http://localhost:8082 in addition.

use Mix.Config
config :http_proxy,
  proxies: [
             %{port: 8080,
               to:   "http://google.com"},
             %{port: 8081,
               to:   "http://yahoo.com"},
             %{port: 8082,
               to:   "http://apple.com"}
            ]

Play and Record mode

• When :record and :play are false, then the http_proxy works just multi port proxy.
• When :record is true, then the http_proxy works to record request which is proxied.
• When :play is true, then the http_proxy works to play request between this the http_proxy and clients.
  • You should set JSON files under mappings in play_path.
  • config.proxies.to must be available URL to succeed generating http client.
    • https://github.com/KazuCocoa/http_proxy/blob/main/lib/http_proxy/handle.ex#L49

use Mix.Config
config :http_proxy,
  proxies: [                   # MUST
             %{port: 8080,     # proxy all request even play or record
               to:   "http://google.com"},
             %{port: 8081,
               to:   "http://yahoo.com"}
            ]
  timeout: 20_000,             # Option, ms to wait http request.
  record: false,               # Option, true: record requests. false: don't record.
  play: false,                 # Option, true: play stored requests. false: don't play.
  export_path: "test/example", # Option, path to export recorded files.
  play_path: "test/data"       # Option, path to read json files as response to.

Example

Record request as the following

{
  "request": {
    "headers": [],
    "method": "GET",
    "options": {
      "aspect": "query_params"
    },
    "remote": "127.0.0.1",
    "request_body": "",
    "url": "http://localhost:8080/hoge/inu?email=neko&pass=123"
  },
  "response": {
    "body_file": "path/to/body_file.json",
    "cookies": {},
    "headers": {
      "Cache-Control": "public, max-age=2592000",
      "Content-Length": "251",
      "Content-Type": "text/html; charset=UTF-8",
      "Date": "Sat, 21 Nov 2015 00:37:38 GMT",
      "Expires": "Mon, 21 Dec 2015 00:37:38 GMT",
      "Location": "http://www.google.com/hoge/inu?email=neko&pass=123",
      "Server": "sffe",
      "X-Content-Type-Options": "nosniff",
      "X-XSS-Protection": "1; mode=block"
    },
    "status_code": 301
  }
}

Response body will save in “path/to/body_file.json”.

Play request with the following JSON data

• Example is https://github.com/KazuCocoa/http_proxy/tree/master/test/data/mappings
• You can set path or path_pattern as attribute under request.
  • If path, the http_proxy check requests are matched completely.
  • If path_pattern, the http_proxy check requests are matched with Regex.
• You can set body or body_file as attribute under response.
  • If body, the http_proxy send the body string.
  • If body_file, the http_proxy send the body_file binary as response.

path and body case

{
  "request": {
    "path": "/request/path",
    "port": 8080,
    "method": "GET"
  },
  "response": {
    "body": "<html>hello world</html>",
    "cookies": {},
    "headers": {
      "Content-Type": "text/html; charset=UTF-8",
      "Server": "GFE/2.0"
    },
    "status_code": 200
  }
}

path_pattern and body_file case

• Pattern match with Regex.match?(Regex.compile!("\A/request.*neko\z"), request_path)
• File.read/2 via file/to/path.json and respond the binary

{
  "request": {
    "path_pattern": "\A/request.*neko\z",
    "port": 8080,
    "method": "GET"
  },
  "response": {
    "body_file": "file/to/path.json",
    "cookies": {},
    "headers": {
      "Content-Type": "text/html; charset=UTF-8",
      "Server": "GFE/2.0"
    },
    "status_code": 200
  }
}

dependencies

$ mix xref graph
lib/http_proxy.ex
└── lib/http_proxy/supervisor.ex
    ├── lib/http_proxy/agent.ex
    │   ├── lib/http_proxy/play/data.ex
    │   │   ├── lib/http_proxy/agent.ex
    │   │   └── lib/http_proxy/play/response.ex
    │   │       ├── lib/http_proxy/play/data.ex
    │   │       └── lib/http_proxy/utils/file.ex
    │   └── lib/http_proxy/play/paths.ex
    │       ├── lib/http_proxy/agent.ex
    │       └── lib/http_proxy/play/response.ex
    └── lib/http_proxy/handle.ex
        ├── lib/http_proxy/play/body.ex
        ├── lib/http_proxy/play/data.ex
        ├── lib/http_proxy/play/paths.ex
        ├── lib/http_proxy/play/response.ex
        └── lib/http_proxy/record/response.ex
            ├── lib/http_proxy/format.ex
            │   └── lib/http_proxy/data.ex (compile)
            └── lib/http_proxy/utils/file.ex

TODO

• record request
• play request
• refactor
• support Regex request path.
• start/stop http_proxy manually
• use vcr
  • integrate https://github.com/parroty/exvcr

styleguide

http://elixir.community/styleguide

LICENSE

MIT. Please read LICENSE.