feat: add 'cors-proxy' CLI that can launch proxy in the background (#3)

Author: billiegoose

README.md

@@ -13,13 +13,38 @@ Namely, it blocks requests that don't look like valid git requests.
 npm install @isomorphic-git/cors-proxy
 ```
 
+## CLI usage
+
+Start proxy on default port 9999:
+
+```sh
+cors-proxy start
+```
+
+Start proxy on a custom port:
+
+```sh
+cors-proxy start -p 9889
+```
+
+Start proxy in daemon mode. It will write the PID of the daemon process to `$PWD/cors-proxy.pid`:
+
+```sh
+cors-proxy start -d
+```
+
+Kill the process with the PID specified in `$PWD/cors-proxy.pid`:
+
+```sh
+cors-proxy stop
+```
+
 ## Configuration
 
 Environment variables:
-- `PORT` the port to listen to
+- `PORT` the port to listen to (if run with `npm start`)
 - `ALLOW_ORIGIN` the value for the 'Access-Control-Allow-Origin' CORS header
 
-
 ## License
 
 This work is released under [The MIT License](https://opensource.org/licenses/MIT)

bin.js

@@ -0,0 +1,60 @@
+#!/usr/bin/env node
+const fs = require('fs')
+const path = require('path')
+const {spawn} = require('child_process')
+const kill = require('tree-kill')
+const minimisted = require('minimisted')
+
+async function main({_: [cmd], p, d}) {
+  switch (cmd) {
+    case 'start': {
+      if (d) require('daemonize-process')()
+      const cmd = path.join(
+        process.cwd(),
+        'node_modules',
+        '.bin',
+        process.platform === 'win32' ? 'micro.cmd' : 'micro'
+      )
+      const args = [
+        `--listen=tcp://0.0.0.0:${p || 9999}`
+      ]
+      let server = spawn(
+        cmd, args,
+        {
+          stdio: 'inherit',
+          windowsHide: true
+        }
+      )
+      fs.writeFileSync(
+        path.join(process.cwd(), 'cors-proxy.pid'),
+        String(process.pid),
+        'utf8'
+      )
+      process.on('exit', server.kill)
+      return
+    }
+    case 'stop': {
+      let pid
+      try {
+        pid = fs.readFileSync(
+          path.join(process.cwd(), 'cors-proxy.pid'),
+          'utf8'
+        );
+      } catch (err) {
+        console.log('No cors-proxy.pid file')
+        return
+      }
+      pid = parseInt(pid)
+      console.log('killing', pid)
+      kill(pid, (err) => {
+        if (err) {
+          console.log(err)
+        } else {
+          fs.unlinkSync(path.join(process.cwd(), 'cors-proxy.pid'))
+        }
+      })
+    }
+  }
+}
+
+minimisted(main)