refactor: backup schreibt Dump zuerst lokal, dann scp

Statt direkter pipe dump→gzip→ssh wird der Dump jetzt in
BACKUP_LOCAL_DIR (default /tmp/logbuch-backup) geschrieben
und danach per scp übertragen. So ist der Dump jederzeit
im Container einsehbar; SSH bleibt optional.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/backup.ts

@@ -1,19 +1,15 @@
 import { spawn } from 'child_process';
+import { createWriteStream, mkdirSync } from 'fs';
+import { join } from 'path';
 
 export function triggerBackup(): void {
   setImmediate(() => runBackup().catch((e) => console.error('[backup] Fehler:', e)));
 }
 
 async function runBackup(): Promise<void> {
-  const sshUrl = process.env.BACKUP_SSH_URL;
-  if (!sshUrl) return;
+  const sshUrl = process.env.BACKUP_SSH_URL || '';
+  const localDir = process.env.BACKUP_LOCAL_DIR || '/tmp/logbuch-backup';
 
-  const match = sshUrl.match(/^([^:]+):(.+)$/);
-  if (!match) {
-    console.error('[backup] BACKUP_SSH_URL muss das Format user@host:/pfad haben');
-    return;
-  }
-  const [, sshHost, remotePath] = match;
   const rawKeyPath = process.env.BACKUP_SSH_KEY_PATH || '';
   const keyPath = rawKeyPath.startsWith('~')
     ? rawKeyPath.replace('~', process.env.HOME || '/root')
@@ -27,16 +23,12 @@ async function runBackup(): Promise<void> {
   const dbUser = process.env.DB_USER || '';
   const dbPass = process.env.DB_PASS || '';
   const dbName = process.env.DB_NAME || 'sternwarte';
-
-  const sshOpts = [
-    ...(keyPath ? ['-i', keyPath] : []),
-    '-o', 'StrictHostKeyChecking=no',
-    '-o', 'BatchMode=yes',
-    '-o', 'ConnectTimeout=15',
-  ];
-
   const dumpBin = process.env.BACKUP_DUMP_CMD || 'mariadb-dump';
 
+  mkdirSync(localDir, { recursive: true });
+  const localPath = join(localDir, filename);
+
+  // Schritt 1: Dump lokal schreiben
   await new Promise<void>((resolve, reject) => {
     const dump = spawn(dumpBin, [
       `-h${dbHost}`, `-P${dbPort}`, `-u${dbUser}`,
@@ -44,34 +36,57 @@ async function runBackup(): Promise<void> {
       `--ignore-table=${dbName}.beos`,
       dbName,
     ], { env: { ...process.env, MYSQL_PWD: dbPass } });
+
     const gzip = spawn('gzip');
-    const ssh = spawn('ssh', [...sshOpts, sshHost, `cat > ${remotePath}/${filename}`]);
+    const file = createWriteStream(localPath);
 
     dump.stdout.pipe(gzip.stdin);
-    gzip.stdout.pipe(ssh.stdin);
+    gzip.stdout.pipe(file);
 
     let dumpErr = '';
-    let sshErr = '';
     dump.stderr.on('data', (d: Buffer) => { dumpErr += d.toString(); });
-    ssh.stderr.on('data', (d: Buffer) => { sshErr += d.toString(); });
-
     dump.on('error', reject);
     gzip.on('error', reject);
-    ssh.on('error', reject);
+    file.on('error', reject);
+    file.on('close', () => {
+      if (dumpErr.trim()) console.log('[backup] dump stderr:', dumpErr.trim());
+      resolve();
+    });
+  });
 
-    dump.on('close', (code) => { if (code !== 0) gzip.stdin.end(); });
-    gzip.on('close', () => ssh.stdin.end());
+  console.log(`[backup] Dump geschrieben: ${localPath}`);
 
-    ssh.on('close', (code) => {
+  // Schritt 2: Per SCP auf externen Server übertragen (optional)
+  if (sshUrl) {
+    const match = sshUrl.match(/^([^:]+):(.+)$/);
+    if (!match) {
+      console.error('[backup] BACKUP_SSH_URL muss das Format user@host:/pfad haben');
+    } else {
+      const [, sshHost, remotePath] = match;
+      const sshOpts = [
+        ...(keyPath ? ['-i', keyPath] : []),
+        '-o', 'StrictHostKeyChecking=no',
+        '-o', 'BatchMode=yes',
+        '-o', 'ConnectTimeout=15',
+      ];
+
+      await new Promise<void>((resolve, reject) => {
+        const scp = spawn('scp', [...sshOpts, localPath, `${sshHost}:${remotePath}/${filename}`]);
+        let scpErr = '';
+        scp.stderr.on('data', (d: Buffer) => { scpErr += d.toString(); });
+        scp.on('error', reject);
+        scp.on('close', (code) => {
           if (code === 0) {
             resolve();
           } else {
-        reject(new Error(`ssh exit ${code}${sshErr ? ': ' + sshErr.trim() : ''}${dumpErr ? ' | dump: ' + dumpErr.trim() : ''}`));
+            reject(new Error(`scp exit ${code}${scpErr ? ': ' + scpErr.trim() : ''}`));
           }
         });
       });
 
-  // Backups älter als 30 Tage löschen
+      console.log(`[backup] ${filename} → ${sshHost}:${remotePath}`);
+
+      // Backups älter als 30 Tage auf Remote löschen
       await new Promise<void>((resolve) => {
         const ssh = spawn('ssh', [
           ...sshOpts, sshHost,
@@ -83,6 +98,6 @@ async function runBackup(): Promise<void> {
           resolve();
         });
       });
-
-  console.log(`[backup] ${filename} → ${sshHost}:${remotePath}`);
+    }
+  }
 }