replaces tree-kill with custom implementation; fixes some security au…

…dit things

.gitignore

@@ -1,4 +1,5 @@
 node_modules
 dist
 *.tgz
-logs
+logs
+.DS_Store

example/nested-process.js

@@ -0,0 +1,4 @@
+var cp = require('child_process');
+
+var child = cp.exec("node -e 'while (true);'");
+console.log(`Running child with pid ${child.pid}`);

mux.config.ts

@@ -18,6 +18,13 @@ const config: MuxConfig = {
         exec: `${dcBin} down`
       }
     },
+    {
+      name: 'nested-process',
+      run: {
+        dir: './example',
+        exec: 'node nested-process.js',
+      }
+    },
     {
       name: 'random number printer',
       install: {

package.json

@@ -15,13 +15,15 @@
   "dependencies": {
     "chalk": "^4.1.0",
     "node-pty": "^0.10.1",
+    "ps-tree": "^1.2.0",
     "tail": "^2.2.6",
     "terminal-kit": "^3.0.0",
     "tree-kill": "^1.2.2",
     "ts-node": "^10.9.1",
     "typescript": "^4.8.4"
   },
   "devDependencies": {
+    "@types/ps-tree": "^1.1.6",
     "@types/tail": "^2.2.1",
     "@types/terminal-kit": "^2.5.0"
   },

src/helpers.ts

@@ -0,0 +1,22 @@
+import psTree from "ps-tree"
+
+/**
+ * Sends the specified signal to the provided pid and all of its descendents.
+ *
+ * Custom implementation of 'tree-kill'. It had some issues with detecting and
+ * stopping grandchildren. It uses `pgrep -P PID` under the hood which does not
+ * return the full tree of pids.
+ */
+export const treeKill = (pid: number, signal: string = 'SIGTERM'): Promise<number[]> => {
+  return new Promise((resolve, reject) => {
+    psTree(pid, (err, children) => {
+      if (err) {
+        reject(err);
+      } else {
+        const childPids = children.map(child => Number(child.PID))
+        childPids.forEach(childPid => process.kill(childPid, signal))
+        resolve(childPids);
+      }
+    });
+  })
+}

src/process.ts

@@ -1,9 +1,9 @@
 import path from "path";
 import fs from 'fs';
 import { Tail } from "tail";
-import treeKill from "tree-kill";
 import { MuxCommand, MuxProcessConfig, MuxLogger, MuxConfig } from "./config";
 import { IPty, spawn } from 'node-pty';
+import { treeKill } from "./helpers";
 
 export class MuxProcess {
   public name: string;
@@ -38,7 +38,8 @@ export class MuxProcess {
         //
         // So instead, use `treeKill` to send a SIGTERM to all child processes
         // at once to ensure a clean exit.
-        treeKill(child.pid, 'SIGTERM');
+        const pids = await treeKill(child.pid, 'SIGTERM');
+        this.logger.debug(`${this.name}: sent SIGTERM to ${pids.join(', ')}`);
       }
     }