Pear gc sidecar (#137)

* gc sidecar as stream, add usage

* fix win

* remove unused code

* use stream, remove GC class

* remove unused prop

* GC as stream, use os.kill

* use text-decoder

* fix win

* gc to lib/gc

* rebase and update lib errors

* remove text-decoder

* cmd to resource, errors

* add await

* inline close

cmd/gc.js

@@ -0,0 +1,33 @@
+'use strict'
+const { print, outputter, InputError } = require('./iface')
+const parse = require('../lib/parse')
+
+const output = outputter('gc', {
+  kill: ({ pid }) => `Killed sidecar with pid: ${pid}`,
+  complete: ({ killed }) => { return killed.length > 0 ? `Total killed sidecars: ${killed.length}` : 'No running sidecars' },
+  error: ({ code, message, stack }) => `GC Error (code: ${code || 'none'}) ${message} ${stack}`
+})
+
+module.exports = (ipc) => async function gc (args) {
+  try {
+    const flags = parse.args(args, {
+      boolean: ['json']
+    })
+    const { _, json } = flags
+    const [resource] = _
+    if (!resource) throw new InputError('A <cmd> must be specified.')
+    if (resource !== 'sidecar') throw new InputError(`Resource '${resource}' is not valid`)
+    const stream = ipc.gc({ pid: Bare.pid, resource }, ipc)
+    await output(json, stream)
+  } catch (err) {
+    if (err instanceof InputError || err.code === 'ERR_INVALID_FLAG') {
+      print(err.message, false)
+      ipc.userData.usage.output('gc')
+    } else {
+      print('An error occured', false)
+    }
+    Bare.exit(1)
+  } finally {
+    await ipc.close()
+  }
+}

cmd/index.js

@@ -8,6 +8,7 @@ const dump = require('./dump')
 const shift = require('./shift')
 const sidecar = require('./sidecar')
 const run = require('./run')
+const gc = require('./gc')
 const parse = require('../lib/parse')
 const { CHECKOUT } = require('../lib/constants')
 
@@ -74,6 +75,7 @@ module.exports = async (ipc) => {
   cmd.add('build', build)
   cmd.add('shift', shift(ipc))
   cmd.add('sidecar', (args) => sidecar(ipc)(args))
+  cmd.add('gc', (args) => gc(ipc)(args))
 
   await cmd.run(argv)
 

cmd/usage.js

@@ -178,6 +178,16 @@ module.exports = ({ fork, length, key }) => {
     --json        Single JSON object
   `
 
+  const gc = ansi.bold(cmd + ' gc')
+  const gcArgs = ansi.bold('<resource>')
+  const gcBrief = 'Garbage Collection. Remove unused resources.'
+  const gcExplain = `${gc} ${gcArgs}
+
+    ${gcBrief}
+
+    --json     Newline delimited JSON output
+  `
+
   const help = ansi.bold(cmd + ' help')
   const helpArgs = ansi.bold('[cmd]')
   const helpBrief = `${ansi.bold('Legend:')} [arg] = optional, <arg> = required, | = or \n    Run ${ansi.bold('pear help')} to output full help for all commands`
@@ -220,6 +230,7 @@ module.exports = ({ fork, length, key }) => {
     seed: seedExplain,
     shift: shiftExplain,
     sidecar: sidecarExplain,
+    gc: gcExplain,
     help: helpExplain,
     output,
     outputVersions,
@@ -235,6 +246,7 @@ module.exports = ({ fork, length, key }) => {
     ${shift} ${ansi.sep} ${dedot(shiftBrief)}
     ${sidecar} ${ansi.sep} ${dedot(sidecarBrief)}
     ${versions} ${ansi.sep} ${dedot(versionsBrief)}
+    ${gc} ${ansi.sep} ${dedot(gcBrief)}
 
     ${helpExplain}
 ${footer}`,
@@ -249,6 +261,7 @@ ${footer}`,
     ${shiftExplain}
     ${sidecarExplain}
     ${versionsExplain}
+    ${gcExplain}
     ${helpExplain}
 ${footer}`
   }

lib/errors.js

@@ -79,6 +79,10 @@ function ERR_UNABLE_TO_FETCH_MANIFEST (msg) {
   return new PearError(msg, 'ERR_CONNECTION', ERR_UNABLE_TO_FETCH_MANIFEST)
 }
 
+function ERR_UNKNOWN_GC_RESOURCE (msg) {
+  return new PearError(msg, 'ERR_UNKNOWN_GC_RESOURCE', ERR_UNKNOWN_GC_RESOURCE)
+}
+
 function ERR_ASSERTION (msg) {
   return new PearError(msg, 'ERR_ASSERTION', ERR_ASSERTION)
 }
@@ -99,5 +103,6 @@ module.exports = {
   ERR_INVALID_APPLICATION_STORAGE,
   ERR_PACKAGE_JSON_NOT_FOUND,
   ERR_UNABLE_TO_FETCH_MANIFEST,
+  ERR_UNKNOWN_GC_RESOURCE,
   ERR_ASSERTION
 }

lib/gc.js

@@ -0,0 +1,68 @@
+'use strict'
+const { isBare, isWindows } = require('which-runtime')
+const os = isBare ? require('bare-os') : require('os')
+const { spawn } = isBare ? require('bare-subprocess') : require('child_process')
+const { Readable } = require('streamx')
+
+module.exports = class GarbageCollector extends Readable {
+  constructor (client, engine) {
+    super()
+    this.client = client
+    this.engine = engine
+  }
+
+  _destroy (cb) {
+    cb(null)
+  }
+
+  sidecar ({ pid }) {
+    const name = 'pear-runtime'
+    const flag = '--sidecar'
+
+    const [sh, args] = isWindows
+      ? ['cmd.exe', ['/c', `wmic process where (name like '%${name}%') get name,executablepath,processid,commandline /format:csv`]]
+      : ['/bin/sh', ['-c', `ps ax | grep -i -- '${name}' | grep -i -- '${flag}'`]]
+
+    const sp = spawn(sh, args)
+    let output = ''
+    let pidIndex = isWindows ? -1 : 0
+    let isHeader = !!isWindows
+    const killed = []
+
+    sp.stdout.on('data', (data) => {
+      output += data.toString()
+      const lines = output.split(isWindows ? '\r\r\n' : '\n')
+      output = lines.pop()
+      for (const line of lines) {
+        if (!line.trim()) continue
+        const columns = line.split(isWindows ? ',' : ' ').filter(col => col)
+        if (isHeader && isWindows) {
+          const index = columns.findIndex(col => /processid/i.test(col.trim()))
+          pidIndex = index !== -1 ? index : 4
+          isHeader = false
+        } else {
+          const id = parseInt(columns[pidIndex])
+          if (!isNaN(id) && ![Bare.pid, sp.pid, pid].includes(id)) {
+            os.kill(id)
+            this.push({ tag: 'kill', data: { pid: id } })
+            killed.push(id)
+          }
+        }
+      }
+    })
+
+    sp.on('exit', (code, signal) => {
+      if (code !== 0 || signal) {
+        this.#error(new Error(`Process exited with code: ${code}, signal: ${signal}`))
+      }
+      this.push({ tag: 'complete', data: { killed } })
+      this.push({ tag: 'final', data: { success: true } })
+      this.push(null)
+    })
+  }
+
+  #error (err) {
+    const { stack, code, message } = err
+    this.push({ tag: 'error', data: { stack, code, message, success: false } })
+  }
+}

lib/sidecar.js

@@ -31,6 +31,7 @@ const Replicator = require('./replicator')
 const parse = require('./parse')
 const Context = require('../ctx/sidecar')
 const registerUrlHandler = require('./url-handler')
+const GarbageCollector = require('./gc')
 
 const {
   PLATFORM_DIR, PLATFORM_LOCK, GC, SOCKET_PATH, CHECKOUT, APPLINGS_PATH, BOOT,
@@ -44,7 +45,8 @@ const {
   ERR_PLATFORM_ERROR,
   ERR_TRACER_FAILED,
   ERR_SHIFT_STORAGE_ERROR,
-  ERR_PERMISSION_REQUIRED
+  ERR_PERMISSION_REQUIRED,
+  ERR_UNKNOWN_GC_RESOURCE
 } = require('./errors')
 
 // ensure that we are registered as a link handler
@@ -1149,6 +1151,13 @@ class Engine extends ReadyResource {
 
   closeClients () { return this.sidecar.closeClients() }
 
+  gc ({ pid, resource }, client) {
+    if (resource !== 'sidecar') throw ERR_UNKNOWN_GC_RESOURCE()
+    const gc = new GarbageCollector(client, this)
+    gc.sidecar({ pid })
+    return gc
+  }
+
   async * shift (params, client) {
     const session = new Session(client)
     try {