Initial commit mit MkDocs-Dokumentation

backend/src/services/processRunner.js

@@ -0,0 +1,99 @@
+const { spawn } = require('child_process');
+const logger = require('./logger').child('PROCESS');
+const { errorToMeta } = require('../utils/errorMeta');
+
+function streamLines(stream, onLine) {
+  let buffer = '';
+  stream.on('data', (chunk) => {
+    buffer += chunk.toString();
+    const parts = buffer.split(/\r\n|\n|\r/);
+    buffer = parts.pop() ?? '';
+
+    for (const line of parts) {
+      if (line.length > 0) {
+        onLine(line);
+      }
+    }
+  });
+
+  stream.on('end', () => {
+    if (buffer.length > 0) {
+      onLine(buffer);
+    }
+  });
+}
+
+function spawnTrackedProcess({
+  cmd,
+  args,
+  cwd,
+  onStdoutLine,
+  onStderrLine,
+  onStart,
+  context = {}
+}) {
+  logger.info('spawn:start', { cmd, args, cwd, context });
+
+  const child = spawn(cmd, args, {
+    cwd,
+    env: process.env,
+    stdio: ['ignore', 'pipe', 'pipe']
+  });
+
+  if (onStart) {
+    onStart(child);
+  }
+
+  if (child.stdout && onStdoutLine) {
+    streamLines(child.stdout, onStdoutLine);
+  }
+
+  if (child.stderr && onStderrLine) {
+    streamLines(child.stderr, onStderrLine);
+  }
+
+  const promise = new Promise((resolve, reject) => {
+    child.on('error', (error) => {
+      logger.error('spawn:error', { cmd, args, context, error: errorToMeta(error) });
+      reject(error);
+    });
+
+    child.on('close', (code, signal) => {
+      logger.info('spawn:close', { cmd, args, code, signal, context });
+      if (code === 0) {
+        resolve({ code, signal });
+      } else {
+        const error = new Error(`Prozess ${cmd} beendet mit Code ${code ?? 'null'} (Signal ${signal ?? 'none'}).`);
+        error.code = code;
+        error.signal = signal;
+        reject(error);
+      }
+    });
+  });
+
+  const cancel = () => {
+    if (child.killed) {
+      return;
+    }
+
+    logger.warn('spawn:cancel:requested', { cmd, args, context, pid: child.pid });
+    child.kill('SIGINT');
+
+    setTimeout(() => {
+      if (!child.killed) {
+        logger.warn('spawn:cancel:force-kill', { cmd, args, context, pid: child.pid });
+        child.kill('SIGKILL');
+      }
+    }, 3000);
+  };
+
+  return {
+    child,
+    promise,
+    cancel
+  };
+}
+
+module.exports = {
+  spawnTrackedProcess
+};