[![Proxy.Py](https://raw.githubusercontent.com/abhinavsingh/proxy.py/develop/ProxyPy.png)](https://github.com/abhinavsingh/proxy.py) [![License](https://img.shields.io/github/license/abhinavsingh/proxy.py.svg)](https://opensource.org/licenses/BSD-3-Clause) [![PyPi Downloads](https://img.shields.io/pypi/dm/proxy.py.svg?color=green)](https://pypi.org/project/proxy.py/) [![Docker Pulls](https://img.shields.io/docker/pulls/abhinavsingh/proxy.py?color=green)](https://hub.docker.com/r/abhinavsingh/proxy.py) [![Build Status](https://travis-ci.org/abhinavsingh/proxy.py.svg?branch=develop)](https://travis-ci.org/abhinavsingh/proxy.py/) [![No Dependencies](https://img.shields.io/static/v1?label=dependencies&message=none&color=green)](https://github.com/abhinavsingh/proxy.py) [![Coverage](https://coveralls.io/repos/github/abhinavsingh/proxy.py/badge.svg?branch=develop)](https://coveralls.io/github/abhinavsingh/proxy.py?branch=develop) [![Tested With MacOS](https://img.shields.io/static/v1?label=tested%20with&message=mac%20OS%20%F0%9F%92%BB&color=brightgreen)](https://developer.apple.com/library/archive/documentation/IDEs/Conceptual/iOS_Simulator_Guide/Introduction/Introduction.html) [![Tested With Ubuntu](https://img.shields.io/static/v1?label=tested%20with&message=Ubuntu%20%F0%9F%96%A5&color=brightgreen)](https://developer.apple.com/library/archive/documentation/IDEs/Conceptual/iOS_Simulator_Guide/Introduction/Introduction.html) [![Tested With Windows](https://img.shields.io/static/v1?label=tested%20with&message=Windows%20%F0%9F%92%BB&color=brightgreen)](https://developer.apple.com/library/archive/documentation/IDEs/Conceptual/iOS_Simulator_Guide/Introduction/Introduction.html) [![Tested With Android](https://img.shields.io/static/v1?label=tested%20with&message=Android%20%F0%9F%93%B1&color=brightgreen)](https://www.android.com/) [![Tested With Android Emulator](https://img.shields.io/static/v1?label=tested%20with&message=Android%20Emulator%20%F0%9F%93%B1&color=brightgreen)](https://developer.android.com/studio/run/emulator-networking.html#proxy) [![Tested With iOS](https://img.shields.io/static/v1?label=tested%20with&message=iOS%20%F0%9F%93%B1&color=brightgreen)](https://developer.apple.com/library/archive/documentation/IDEs/Conceptual/iOS_Simulator_Guide/Introduction/Introduction.html) [![Tested With iOS Simulator](https://img.shields.io/static/v1?label=tested%20with&message=iOS%20Simulator%20%F0%9F%93%B1&color=brightgreen)](https://developer.apple.com/library/archive/documentation/IDEs/Conceptual/iOS_Simulator_Guide/Introduction/Introduction.html) [![Maintenance](https://img.shields.io/static/v1?label=maintained%3F&message=yes&color=green)](https://gitHub.com/abhinavsingh/proxy.py/graphs/commit-activity) [![Ask Me Anything](https://img.shields.io/static/v1?label=need%20help%3F&message=ask&color=green)](https://twitter.com/imoracle) [![Contributions Welcome](https://img.shields.io/static/v1?label=contributions&message=welcome%20%F0%9F%91%8D&color=green)](https://github.com/abhinavsingh/proxy.py/issues) [![Gitter](https://badges.gitter.im/proxy-py/community.svg)](https://gitter.im/proxy-py/community) [![Python 3.6](https://img.shields.io/badge/python-3.6-blue.svg)](https://www.python.org/downloads/release/python-360/) [![Python 3.7](https://img.shields.io/badge/python-3.7-blue.svg)](https://www.python.org/downloads/release/python-370/) [![Checked with mypy](https://img.shields.io/static/v1?label=mypy&message=checked&color=blue)](http://mypy-lang.org/) [![Become a Backer](https://opencollective.com/proxypy/tiers/backer.svg?avatarHeight=36)](https://opencollective.com/proxypy) Table of Contents ================= * [Features](#features) * [Install](#install) * [Stable version](#stable-version) * [Development version](#development-version) * [Start proxy.py](#start-proxypy) * [Command Line](#command-line) * [Docker Image](#docker-image) * [Plugin Examples](#plugin-examples) * [ProposedRestApiPlugin](#proposedrestapiplugin) * [RedirectToCustomServerPlugin](#redirecttocustomserverplugin) * [FilterByUpstreamHostPlugin](#filterbyupstreamhostplugin) * [CacheResponsesPlugin](#cacheresponsesplugin) * [ManInTheMiddlePlugin](#maninthemiddleplugin) * [Plugin Ordering](#plugin-ordering) * [End-to-End Encryption](#end-to-end-encryption) * [TLS Interception](#tls-interception) * [import proxy.py](#import-proxypy) * [Plugin Developer and Contributor Guide](#plugin-developer-and-contributor-guide) * [Everything is a plugin](#everything-is-a-plugin) * [Internal Architecture](#internal-architecture) * [Internal Documentation](#internal-documentation) * [Sending a Pull Request](#sending-a-pull-request) * [Frequently Asked Questions](#frequently-asked-questions) * [Unable to connect with proxy.py from remote host](#unable-to-connect-with-proxypy-from-remote-host) * [Basic auth not working with a browser](#basic-auth-not-working-with-a-browser) * [Docker image not working on MacOS](#docker-image-not-working-on-macos) * [Flags](#flags) Features ======== - Lightweight - Distributed as a single file module `~50KB` - Uses only `~5-20MB` RAM - No external dependency other than standard Python library - Programmable - Optionally enable builtin Web Server - Customize proxy and http routing via [plugins](https://github.com/abhinavsingh/proxy.py/blob/develop/plugin_examples.py) - Enable plugin using command line option e.g. `--plugins plugin_examples.CacheResponsesPlugin` - Plugin API is currently in development state, expect breaking changes. - Secure - Enable end-to-end encryption between clients and `proxy.py` using TLS - See [End-to-End Encryption](#end-to-end-encryption) - Man-In-The-Middle - Can decrypt TLS traffic between clients and upstream servers - See [TLS Encryption](#tls-interception) - Supported proxy protocols - `http` - `https` - `http2` - `websockets` - Optimized for large file uploads and downloads - IPv4 and IPv6 support - Basic authentication support - Can serve a [PAC (Proxy Auto-configuration)](https://en.wikipedia.org/wiki/Proxy_auto-config) file - See `--pac-file` and `--pac-file-url-path` flags Install ======= ## Stable version $ pip install --upgrade proxy.py ## Development version $ pip install git+https://github.com/abhinavsingh/proxy.py.git@develop For `Docker` usage see [Docker Image](#docker-image). Start proxy.py ============== ## Command line Simply type `proxy.py` on command line to start it with default configuration. ``` $ proxy.py ...[redacted]... - Loaded plugin ...[redacted]... - Starting 8 workers ...[redacted]... - Started server on ::1:8899 ``` Things to notice from above logs: - `Loaded plugin` - `proxy.py` will load `HttpProxyPlugin` by default. It adds `http(s)` proxy server capabilities to `proxy.py` - `Started N workers` - Use `--num-workers` flag to customize number of `Worker` processes. By default, `proxy.py` will start as many workers as there are CPU cores on the machine. - `Started server on ::1:8899` - By default, `proxy.py` listens on IPv6 `::1`, which is equivalent of IPv4 `127.0.0.1`. If you want to access `proxy.py` externally, use `--hostname ::` or `--hostname 0.0.0.0` or bind to any other interface available on your machine. - `Port 8899` - Use `--port` flag to customize default TCP port. All the logs above are `INFO` level logs, default `--log-level` for `proxy.py`. Lets start `proxy.py` with `DEBUG` level logging: ``` $ proxy.py --log-level d ...[redacted]... - Open file descriptor soft limit set to 1024 ...[redacted]... - Loaded plugin ...[redacted]... - Started 8 workers ...[redacted]... - Started server on ::1:8899 ``` As we can see, before starting up: - `proxy.py` also tried to set open file limit `ulimit` on the system. - Default value for `--open-file-limit` used is `1024`. - `--open-file-limit` flag is a no-op on `Windows` operating systems. See [flags](#flags) for full list of available configuration options. ## Docker image $ docker run -it -p 8899:8899 --rm abhinavsingh/proxy.py:v1.0.0 By default `docker` binary is started with IPv4 networking flags: --hostname 0.0.0.0 --port 8899 To override input flags, start docker image as follows. For example, to check `proxy.py --version`: $ docker run -it \ -p 8899:8899 \ --rm abhinavsingh/proxy.py:v1.0.0 \ --version [![WARNING](https://img.shields.io/static/v1?label=MacOS&message=warning&color=red)](https://github.com/moby/vpnkit/issues/469) `docker` image is currently broken on `macOS` due to incompatibility with [vpnkit](https://github.com/moby/vpnkit/issues/469). Plugin Examples =============== See [plugin_examples.py](https://github.com/abhinavsingh/proxy.py/blob/develop/plugin_examples.py) for full code. All the examples below also works with `https` traffic but require additional flags and certificate generation. See [TLS Interception](#tls-interception). ## ProposedRestApiPlugin Mock responses for your server REST API. Use to test and develop client side applications without need of an actual upstream REST API server. Start `proxy.py` as: ``` $ proxy.py \ --plugins plugin_examples.ProposedRestApiPlugin ``` Verify mock API response using `curl -x localhost:8899 http://api.example.com/v1/users/` ``` {"count": 2, "next": null, "previous": null, "results": [{"email": "you@example.com", "groups": [], "url": "api.example.com/v1/users/1/", "username": "admin"}, {"email": "someone@example.com", "groups": [], "url": "api.example.com/v1/users/2/", "username": "admin"}]} ``` Verify the same by inspecting `proxy.py` logs: ``` 2019-09-27 12:44:02,212 - INFO - pid:7077 - access_log:1210 - ::1:64792 - GET None:None/v1/users/ - None None - 0 byte ``` Access log shows `None:None` as server `ip:port`. `None` simply means that the server connection was never made, since response was returned by our plugin. Now modify `ProposedRestApiPlugin` to returns REST API mock responses as expected by your clients. ## RedirectToCustomServerPlugin Redirects all incoming `http` requests to custom web server. By default, it redirects client requests to inbuilt web server, also running on `8899` port. Start `proxy.py` and enable inbuilt web server: ``` $ proxy.py \ --enable-web-server \ --plugins plugin_examples.RedirectToCustomServerPlugin ``` Verify using `curl -v -x localhost:8899 http://google.com` ``` ... [redacted] ... < HTTP/1.1 404 NOT FOUND < Server: proxy.py v1.0.0 < Connection: Close < * Closing connection 0 ``` Above `404` response was returned from `proxy.py` web server. Verify the same by inspecting the logs for `proxy.py`. Along with the proxy request log, you must also see a http web server request log. ``` 2019-09-24 19:09:33,602 - INFO - pid:49996 - access_log:1241 - ::1:49525 - GET / 2019-09-24 19:09:33,603 - INFO - pid:49995 - access_log:1157 - ::1:49524 - GET localhost:8899/ - 404 NOT FOUND - 70 bytes ``` ## FilterByUpstreamHostPlugin Drops traffic by inspecting upstream host. By default, plugin drops traffic for `google.com` and `www.google.com`. Start `proxy.py` as: ``` $ proxy.py \ --plugins plugin_examples.FilterByUpstreamHostPlugin ``` Verify using `curl -v -x localhost:8899 http://google.com`: ``` ... [redacted] ... < HTTP/1.1 418 I'm a tea pot < Proxy-agent: proxy.py v1.0.0 * no chunk, no close, no size. Assume close to signal end < * Closing connection 0 ``` Above `418 I'm a tea pot` is sent by our plugin. Verify the same by inspecting logs for `proxy.py`: ``` 2019-09-24 19:21:37,893 - ERROR - pid:50074 - handle_readables:1347 - ProtocolException type raised Traceback (most recent call last): ... [redacted] ... 2019-09-24 19:21:37,897 - INFO - pid:50074 - access_log:1157 - ::1:49911 - GET None:None/ - None None - 0 bytes ``` ## CacheResponsesPlugin Caches Upstream Server Responses. Start `proxy.py` as: ``` $ proxy.py \ --plugins plugin_examples.CacheResponsesPlugin ``` Verify using `curl -v -x localhost:8899 http://httpbin.org/get`: ``` ... [redacted] ... < HTTP/1.1 200 OK < Access-Control-Allow-Credentials: true < Access-Control-Allow-Origin: * < Content-Type: application/json < Date: Wed, 25 Sep 2019 02:24:25 GMT < Referrer-Policy: no-referrer-when-downgrade < Server: nginx < X-Content-Type-Options: nosniff < X-Frame-Options: DENY < X-XSS-Protection: 1; mode=block < Content-Length: 202 < Connection: keep-alive < { "args": {}, "headers": { "Accept": "*/*", "Host": "httpbin.org", "User-Agent": "curl/7.54.0" }, "origin": "1.2.3.4, 5.6.7.8", "url": "https://httpbin.org/get" } * Connection #0 to host localhost left intact ``` Get path to the cache file from `proxy.py` logs: ``` ... [redacted] ... - GET httpbin.org:80/get - 200 OK - 556 bytes ... [redacted] ... - Cached response at /var/folders/k9/x93q0_xn1ls9zy76m2mf2k_00000gn/T/httpbin.org-1569378301.407512.txt ``` Verify contents of the cache file `cat /path/to/your/cache/httpbin.org.txt` ``` HTTP/1.1 200 OK Access-Control-Allow-Credentials: true Access-Control-Allow-Origin: * Content-Type: application/json Date: Wed, 25 Sep 2019 02:24:25 GMT Referrer-Policy: no-referrer-when-downgrade Server: nginx X-Content-Type-Options: nosniff X-Frame-Options: DENY X-XSS-Protection: 1; mode=block Content-Length: 202 Connection: keep-alive { "args": {}, "headers": { "Accept": "*/*", "Host": "httpbin.org", "User-Agent": "curl/7.54.0" }, "origin": "1.2.3.4, 5.6.7.8", "url": "https://httpbin.org/get" } ``` ## ManInTheMiddlePlugin Modifies upstream server responses. Start `proxy.py` as: ``` $ proxy.py \ --plugins plugin_examples.ManInTheMiddlePlugin ``` Verify using `curl -v -x localhost:8899 http://google.com`: ``` ... [redacted] ... < HTTP/1.1 200 OK < Content-Length: 28 < * Connection #0 to host localhost left intact Hello from man in the middle ``` Response body `Hello from man in the middle` is sent by our plugin. ## Plugin Ordering When using multiple plugins, depending upon plugin functionality, it might be worth considering the order in which plugins are passed on the command line. Plugins are called in the same order as they are passed. Example, say we are using both `FilterByUpstreamHostPlugin` and `RedirectToCustomServerPlugin`. Idea is to drop all incoming `http` requests for `google.com` and `www.google.com` and redirect other `http` requests to our inbuilt web server. Hence, in this scenario it is important to use `FilterByUpstreamHostPlugin` before `RedirectToCustomServerPlugin`. If we enable `RedirectToCustomServerPlugin` before `FilterByUpstreamHostPlugin`, `google` requests will also get redirected to inbuilt web server, instead of being dropped. End-to-End Encryption ===================== By default, `proxy.py` uses `http` protocol for communication with clients e.g. `curl`, `browser`. For enabling end-to-end encrypting using `tls` / `https` first generate certificates: ``` make https-certificates ``` Start `proxy.py` as: ``` $ proxy.py \ --cert-file https-cert.pem \ --key-file https-key.pem ``` Verify using `curl -x https://localhost:8899 --proxy-cacert https-cert.pem https://httpbin.org/get`: ``` { "args": {}, "headers": { "Accept": "*/*", "Host": "httpbin.org", "User-Agent": "curl/7.54.0" }, "origin": "1.2.3.4, 5.6.7.8", "url": "https://httpbin.org/get" } ``` TLS Interception ================= By default, `proxy.py` doesn't decrypt `https` traffic between client and server. To enable TLS interception first generate CA certificates: ``` make ca-certificates ``` Lets also enable `CacheResponsePlugin` so that we can verify decrypted response from the server. Start `proxy.py` as: ``` $ proxy.py \ --plugins plugin_examples.CacheResponsesPlugin \ --ca-key-file ca-key.pem \ --ca-cert-file ca-cert.pem \ --ca-signing-key-file ca-signing-key.pem ``` Verify using `curl -v -x localhost:8899 --cacert ca-cert.pem https://httpbin.org/get` ``` * issuer: C=US; ST=CA; L=SanFrancisco; O=proxy.py; OU=CA; CN=Proxy PY CA; emailAddress=proxyca@mailserver.com * SSL certificate verify ok. > GET /get HTTP/1.1 ... [redacted] ... < Connection: keep-alive < { "args": {}, "headers": { "Accept": "*/*", "Host": "httpbin.org", "User-Agent": "curl/7.54.0" }, "origin": "1.2.3.4, 5.6.7.8", "url": "https://httpbin.org/get" } ``` The `issuer` line confirms that response was intercepted. Also verify the contents of cached response file. Get path to the cache file from `proxy.py` logs. `$ cat /path/to/your/tmp/directory/httpbin.org-1569452863.924174.txt` ``` HTTP/1.1 200 OK Access-Control-Allow-Credentials: true Access-Control-Allow-Origin: * Content-Type: application/json Date: Wed, 25 Sep 2019 23:07:05 GMT Referrer-Policy: no-referrer-when-downgrade Server: nginx X-Content-Type-Options: nosniff X-Frame-Options: DENY X-XSS-Protection: 1; mode=block Content-Length: 202 Connection: keep-alive { "args": {}, "headers": { "Accept": "*/*", "Host": "httpbin.org", "User-Agent": "curl/7.54.0" }, "origin": "1.2.3.4, 5.6.7.8", "url": "https://httpbin.org/get" } ``` Viola!!! If you remove CA flags, encrypted data will be found in the cached file instead of plain text. Now use CA flags other [plugin examples](#plugin-examples) to make them work for `https` traffic. import proxy.py =============== You can directly import `proxy.py` into your `Python` code. Example: ``` $ python >>> import proxy >>> >>> # Generate HTTP GET request >>> proxy.build_http_request(b'GET', b'/') b'GET / HTTP/1.1\r\n\r\n' >>> >>> # Generate HTTP GET request with headers >>> proxy.build_http_request(b'GET', b'/', headers={b'Connection': b'close'}) b'GET / HTTP/1.1\r\nConnection: close\r\n\r\n' >>> >>> # Generate HTTP POST request with headers and body >>> import json >>> proxy.build_http_request(b'POST', b'/form', headers={b'Content-type': b'application/json'}, body=proxy.bytes_(json.dumps({'email': 'hello@world.com'}))) b'POST /form HTTP/1.1\r\nContent-type: application/json\r\n\r\n{"email": "hello@world.com"}' ``` To start `proxy.py` server from imported `proxy.py` module, simply do: ``` import sys import proxy if __name__ == '__main__': proxy.main(sys.argv[1:]) ``` Plugin Developer and Contributor Guide ====================================== ## Everything is a plugin As you might have guessed by now, in `proxy.py` everything is a plugin. - We enabled proxy server plugins using `--plugins` flag. All the [plugin examples](#plugin-examples) were implementing `HttpProxyBasePlugin`. See documentation of [HttpProxyBasePlugin](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L894-L938) for available lifecycle hooks. Use `HttpProxyBasePlugin` to modify behavior of http(s) proxy protocol between client and upstream server. Example, [FilterByUpstreamHostPlugin](#filterbyupstreamhostplugin). - We also enabled inbuilt web server using `--enable-web-server`. Inbuilt web server implements `ProtocolHandlerPlugin` plugin. See documentation of [ProtocolHandlerPlugin](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L793-L850) for available lifecycle hooks. Use `ProtocolHandlerPlugin` to add new features for http(s) clients. Example, [HttpWebServerPlugin](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L1185-L1260). - There also is a `--disable-http-proxy` flag. It disables inbuilt proxy server. Use this flag with `--enable-web-server` flag to run `proxy.py` as a programmable http(s) server. [HttpProxyPlugin](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L941-L1182) also implements `ProtocolHandlerPlugin`. ## Internal Architecture - [ProtocolHandler](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L1263-L1440) thread is started with the accepted [TcpClientConnection](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L230-L237). `ProtocolHandler` is responsible for parsing incoming client request and invoking `ProtocolHandlerPlugin` lifecycle hooks. - `HttpProxyPlugin` which implements `ProtocolHandlerPlugin` also has its own plugin mechanism. Its responsibility is to establish connection between client and upstream [TcpServerConnection](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L204-L227) and invoke `HttpProxyBasePlugin` lifecycle hooks. - `ProtocolHandler` threads are started by [Worker](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L424-L472) processes. - `--num-workers` `Worker` processes are started by [AcceptorPool](https://github.com/abhinavsingh/proxy.py/blob/b03629fa0df1595eb4995427bc601063be7fdca9/proxy.py#L368-L421) on start-up. - `AcceptorPool` listens on server socket and pass the handler to `Worker` processes. Workers are responsible for accepting new client connections and starting `ProtocolHandler` thread. ## Sending a Pull Request Install dependencies for local development testing: `$ pip install -r requirements-testing.txt` Every pull request goes through set of tests which must pass: - `mypy`: Run `make lint` locally for compliance check. Fix all warnings and errors before sending out a PR. - `coverage`: Run `make coverage` locally for coverage report. Its ideal to add tests for any critical change. Depending upon the change, it's ok if test coverage falls by `<0.5%`. - `formatting`: Run `make autopep8` locally to format the code in-place. `autopep8` is run with `--aggresive` flag. Sometimes it _may_ result in weird formatting. But let's stick to one consistent formatting tool. I am open to flag changes for `autopep8`. ## Internal Documentation Browse through internal class hierarchy and documentation using `pydoc3`. Example: ``` $ pydoc3 proxy Help on module proxy: NAME proxy DESCRIPTION proxy.py ~~~~~~~~ Lightweight, Programmable, TLS interceptor Proxy for HTTP(S), HTTP2, WebSockets protocols in a single Python file. :copyright: (c) 2013-present by Abhinav Singh and contributors. :license: BSD, see LICENSE for more details. CLASSES abc.ABC(builtins.object) HttpProxyBasePlugin HttpWebServerRoutePlugin HttpWebServerPacFilePlugin ProtocolHandlerPlugin HttpProxyPlugin HttpWebServerPlugin TcpConnection TcpClientConnection TcpServerConnection builtins.Exception(builtins.BaseException) ProtocolException HttpRequestRejected ProxyAuthenticationFailed ProxyConnectionFailed TcpConnectionUninitializedException builtins.object AcceptorPool ChunkParser HttpParser ProtocolConfig Websocket WebsocketFrame builtins.tuple(builtins.object) ChunkParserStates HttpParserStates HttpParserTypes HttpProtocolTypes TcpConnectionTypes multiprocessing.context.Process(multiprocessing.process.BaseProcess) Worker threading.Thread(builtins.object) ProtocolHandler ... [ truncated ] ... ``` Frequently Asked Questions ========================== ## Unable to connect with proxy.py from remote host Make sure `proxy.py` is listening on correct network interface. Try following flags: - For IPv6 `--hostname ::` - For IPv4 `--hostname 0.0.0.0` ## Basic auth not working with a browser Most likely it's a browser integration issue with system keychain. - First verify that basic auth is working using `curl` `curl -v -x username:password@localhost:8899 https://httpbin.org/get` - See [this thread](https://github.com/abhinavsingh/proxy.py/issues/89#issuecomment-534845710) for further details. ## Docker image not working on macOS It's a compatibility issue with `vpnkit`. See [moby/vpnkit exhausts docker resources](https://github.com/abhinavsingh/proxy.py/issues/43) and [Connection refused: The proxy could not connect](https://github.com/moby/vpnkit/issues/469) for some background. Flags ===== ``` $ proxy.py -h usage: proxy.py [-h] [--backlog BACKLOG] [--basic-auth BASIC_AUTH] [--ca-key-file CA_KEY_FILE] [--ca-cert-dir CA_CERT_DIR] [--ca-cert-file CA_CERT_FILE] [--ca-signing-key-file CA_SIGNING_KEY_FILE] [--cert-file CERT_FILE] [--client-recvbuf-size CLIENT_RECVBUF_SIZE] [--disable-headers DISABLE_HEADERS] [--disable-http-proxy] [--enable-web-server] [--hostname HOSTNAME] [--key-file KEY_FILE] [--log-level LOG_LEVEL] [--log-file LOG_FILE] [--log-format LOG_FORMAT] [--num-workers NUM_WORKERS] [--open-file-limit OPEN_FILE_LIMIT] [--pac-file PAC_FILE] [--pac-file-url-path PAC_FILE_URL_PATH] [--pid-file PID_FILE] [--plugins PLUGINS] [--port PORT] [--server-recvbuf-size SERVER_RECVBUF_SIZE] [--version] proxy.py v1.0.0 optional arguments: -h, --help show this help message and exit --backlog BACKLOG Default: 100. Maximum number of pending connections to proxy server --basic-auth BASIC_AUTH Default: No authentication. Specify colon separated user:password to enable basic authentication. --ca-key-file CA_KEY_FILE Default: None. CA key to use for signing dynamically generated HTTPS certificates. If used, must also pass --ca-cert-file and --ca-signing-key-file --ca-cert-dir CA_CERT_DIR Default: ~/.proxy.py. Directory to store dynamically generated certificates. Also see --ca-key-file, --ca- cert-file and --ca-signing-key-file --ca-cert-file CA_CERT_FILE Default: None. Signing certificate to use for signing dynamically generated HTTPS certificates. If used, must also pass --ca-key-file and --ca-signing-key-file --ca-signing-key-file CA_SIGNING_KEY_FILE Default: None. CA signing key to use for dynamic generation of HTTPS certificates. If used, must also pass --ca-key-file and --ca-cert-file --cert-file CERT_FILE Default: None. Server certificate to enable end-to-end TLS encryption with clients. If used, must also pass --key-file. --client-recvbuf-size CLIENT_RECVBUF_SIZE Default: 1 MB. Maximum amount of data received from the client in a single recv() operation. Bump this value for faster uploads at the expense of increased RAM. --disable-headers DISABLE_HEADERS Default: None. Comma separated list of headers to remove before dispatching client request to upstream server. --disable-http-proxy Default: False. Whether to disable proxy.HttpProxyPlugin. --enable-web-server Default: False. Whether to enable proxy.HttpWebServerPlugin. --hostname HOSTNAME Default: ::1. Server IP address. --key-file KEY_FILE Default: None. Server key file to enable end-to-end TLS encryption with clients. If used, must also pass --cert-file. --log-level LOG_LEVEL Valid options: DEBUG, INFO (default), WARNING, ERROR, CRITICAL. Both upper and lowercase values are allowed. You may also simply use the leading character e.g. --log-level d --log-file LOG_FILE Default: sys.stdout. Log file destination. --log-format LOG_FORMAT Log format for Python logger. --num-workers NUM_WORKERS Defaults to number of CPU cores. --open-file-limit OPEN_FILE_LIMIT Default: 1024. Maximum number of files (TCP connections) that proxy.py can open concurrently. --pac-file PAC_FILE A file (Proxy Auto Configuration) or string to serve when the server receives a direct file request. Using this option enables proxy.HttpWebServerPlugin. --pac-file-url-path PAC_FILE_URL_PATH Default: /. Web server path to serve the PAC file. --pid-file PID_FILE Default: None. Save parent process ID to a file. --plugins PLUGINS Comma separated plugins --port PORT Default: 8899. Server port. --server-recvbuf-size SERVER_RECVBUF_SIZE Default: 1 MB. Maximum amount of data received from the server in a single recv() operation. Bump this value for faster downloads at the expense of increased RAM. --version, -v Prints proxy.py version. Proxy.py not working? Report at: https://github.com/abhinavsingh/proxy.py/issues/new ```