Add `shell-proxy` plugin (#8692)

plugins/shell-proxy/README.md

+# Shell Proxy oh-my-zsh plugin
+
+This a pure user-space program, shell-proxy setter, written Python3 and Bash.
+
+100% only no side-effects, only effect **environment variables** and **aliases**
+
+## Key feature
+
+- Support Ubuntu, Archlinux, etc (Linux)
+- Support macOS
+- Support git via based-`$GIT_SSH`
+- Support ssh, sftp, scp, slogin and ssh-copy-id via based-`alias`
+- Built-in Auto-complete
+
+## Usage
+
+Method 1:
+
+`$DEFAULT_PROXY` is the proxy URL you will set
+
+Method 2:
+
+Write a program to `$HOME/.config/proxy` in the file.
+
+Example program:
+
+```bash
+#!/bin/bash
+# The file path: $HOME/.config/proxy
+if [[ "$OSTYPE" == "darwin"* ]]; then
+  echo "http://127.0.0.1:6152" # Surge Mac
+else
+  echo "http://127.0.0.1:8123" # polipo
+fi
+```
+
+Method 3:
+
+The working path of **Method 2** can be changed via `$CONFIG_PROXY`
+
+## Reference
+
+- `$GIT_SSH`: <https://www.git-scm.com/docs/git#Documentation/git.txt-codeGITSSHcode>
+- OpenSSH manual: <https://man.openbsd.org/ssh>
+
+## Maintainer
+
+- <https://github.com/septs>
+
+## The oh-my-zsh plugin (shell-proxy)
+
+Public Domain

plugins/shell-proxy/proxy.py

+#!/usr/bin/env python3
+import os
+import sys
+from subprocess import check_output, list2cmdline
+
+cwd = os.path.dirname(__file__)
+ssh_agent = os.path.join(cwd, "ssh-agent.py")
+user_proxy = os.environ.get("CONFIG_PROXY", os.path.expandvars("$HOME/.config/proxy"))
+
+
+def get_http_proxy():
+    if "DEFAULT_PROXY" in os.environ:
+        return os.environ["DEFAULT_PROXY"]
+    if os.path.isfile(user_proxy):
+        return check_output(user_proxy).decode("utf-8").strip()
+    raise Exception("Not found, Proxy configuration")
+
+
+def make_proxies(url: str):
+    proxies = {"%s_PROXY" % _: url for _ in ("HTTP", "HTTPS", "FTP", "RSYNC", "ALL")}
+    proxies.update({name.lower(): value for (name, value) in proxies.items()})
+    proxies["GIT_SSH"] = ssh_agent
+    return proxies
+
+
+def merge(mapping: dict):
+    return ("%s=%s" % _ for _ in mapping.items())
+
+
+class CommandSet:
+    proxies = make_proxies(get_http_proxy())
+    aliases = {
+        _: "env NAME=%s %s" % (_, ssh_agent)
+        for _ in ("ssh", "sftp", "scp", "slogin", "ssh-copy-id")
+    }
+
+    def enable(self):
+        cmdline("export", *merge(self.proxies))
+        cmdline("alias", *merge(self.aliases))
+
+    def disable(self):
+        cmdline("unset", *self.proxies.keys())
+        cmdline("unalias", *self.aliases.keys())
+
+    def status(self):
+        proxies = (
+            "%11s = %s" % (name, os.environ[name])
+            for name in self.proxies.keys()
+            if name in os.environ
+        )
+        for _ in proxies:
+            cmdline("echo", _)
+
+    def usage(self):
+        cmdline("echo", "usage: proxy {enable,disable,status}")
+        self.status()
+
+
+def cmdline(*items):
+    print(list2cmdline(items))
+
+
+def main():
+    command = CommandSet()
+    if len(sys.argv) == 1:
+        command.usage()
+        sys.exit(-1)
+    getattr(command, sys.argv[1], command.usage)()
+
+
+if __name__ == "__main__":
+    main()

plugins/shell-proxy/shell-proxy.plugin.zsh

+#!/usr/bin/bash
+# shellcheck disable=SC1090
+
+__PROXY__="${0:A:h}/proxy.py"
+
+proxy() {
+	source <("$__PROXY__" "$1")
+}
+
+_proxy() {
+	local -r commands=('enable' 'disable' 'status')
+	compset -P '*,'
+	compadd -S '' "${commands[@]}"
+}
+
+compdef '_proxy' 'proxy'

plugins/shell-proxy/ssh-agent.py

+#!/usr/bin/env python3
+import os
+import subprocess
+import sys
+
+ssh_proxy = os.path.join(os.path.dirname(__file__), "ssh-proxy.py")
+
+argv = [
+    os.environ.get("NAME", "ssh"),
+    "-o",
+    "ProxyCommand={} %h %p".format(ssh_proxy),
+    "-o",
+    "Compression=yes",
+]
+
+subprocess.call(argv + sys.argv[1:], env=os.environ)

plugins/shell-proxy/ssh-proxy.py

+#!/usr/bin/env python3
+import os
+import subprocess
+import sys
+import urllib.parse
+
+proxy = next(os.environ[_] for _ in ("HTTP_PROXY", "HTTPS_PROXY") if _ in os.environ)
+argv = [
+    "nc",
+    "-X",
+    "connect",
+    "-x",
+    urllib.parse.urlparse(proxy).netloc,  # proxy-host:proxy-port
+    sys.argv[1],  # host
+    sys.argv[2],  # port
+]
+
+subprocess.call(argv)