Add systemd compatibility and verbose logging to Seafile MySQL backup hook

Enhance the Seafile MySQL dump hook with better debugging capabilities
and systemd service compatibility:
- Redirect all output to syslog for systemd journal integration
- Add Docker socket accessibility check before attempting dumps
- Add detailed logging at each step for troubleshooting
- Improve error handling with explicit exit codes
- Add context information (USER, PWD, HOME) for systemd debugging

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

hooks/seafile-docker-mysql-backup.sh

@@ -8,7 +8,12 @@ DATE=$(date +%Y%m%d-%H%M)
 SEAFILE_CONTAINER="seafile"     # Nom de votre conteneur Seafile
 MYSQL_CONTAINER="seafile-mysql" # Ou le nom de votre conteneur MySQL
 
+# Log pour debug systemd
+exec 1> >(logger -t seafile-backup -p user.info)
+exec 2> >(logger -t seafile-backup -p user.error)
+
 echo "[$(date)] Démarrage dump MySQL Seafile..."
+echo "Contexte: USER=$USER, PWD=$PWD, HOME=$HOME"
 
 # Créer le répertoire de backup
 mkdir -p "$BACKUP_DIR"
@@ -33,7 +38,16 @@ fi
 echo "✓ Utilisateur MySQL: $MYSQL_USER"
 echo "✓ Mot de passe MySQL défini"
 
+# Vérifier l'accès à Docker
+echo "Test accès Docker..."
+if ! docker info >/dev/null 2>&1; then
+  echo "❌ Impossible d'accéder à Docker (socket /var/run/docker.sock)"
+  exit 1
+fi
+echo "✓ Docker accessible"
+
 # Vérifier que le conteneur existe et tourne
+echo "Recherche du conteneur $MYSQL_CONTAINER..."
 if ! docker ps --format '{{.Names}}' | grep -q "^${MYSQL_CONTAINER}$"; then
   echo "❌ Conteneur $MYSQL_CONTAINER non trouvé ou arrêté"
   echo "Conteneurs disponibles:"
@@ -43,16 +57,27 @@ fi
 echo "✓ Conteneur $MYSQL_CONTAINER trouvé"
 
 # Dump unique avec toutes les bases
-echo "→ Dump des bases Seafile..."
-if timeout 300 docker exec "$MYSQL_CONTAINER" mysqldump \
+DUMP_FILE="$BACKUP_DIR/seafile-all-$DATE.sql"
+echo "→ Lancement du dump MySQL vers: $DUMP_FILE"
+echo "→ Commande: docker exec $MYSQL_CONTAINER mysqldump -u $MYSQL_USER ..."
+
+# Utiliser une approche sans redirection 2>&1 qui peut bloquer
+set +e  # Désactiver temporairement set -e pour capturer le code de sortie
+timeout 300 docker exec "$MYSQL_CONTAINER" mysqldump \
   -u "$MYSQL_USER" -p"${SEAFILE_DB_PASSWORD}" \
   --single-transaction --quick --databases \
-  ccnet_db seafile_db seahub_db > "$BACKUP_DIR/seafile-all-$DATE.sql" 2>&1; then
+  ccnet_db seafile_db seahub_db > "$DUMP_FILE" 2>&1
+DUMP_EXIT_CODE=$?
+set -e
 
-  SIZE=$(du -h "$BACKUP_DIR/seafile-all-$DATE.sql" | cut -f1)
+echo "→ Code de sortie mysqldump: $DUMP_EXIT_CODE"
+
+if [ $DUMP_EXIT_CODE -eq 0 ] && [ -f "$DUMP_FILE" ] && [ -s "$DUMP_FILE" ]; then
+  SIZE=$(du -h "$DUMP_FILE" | cut -f1)
   echo "✓ Dump créé: seafile-all-$DATE.sql ($SIZE)"
 else
-  echo "❌ Échec du dump (timeout ou erreur mysqldump)"
+  echo "❌ Échec du dump (code sortie: $DUMP_EXIT_CODE)"
+  [ -f "$DUMP_FILE" ] && echo "Taille fichier: $(stat -f %z "$DUMP_FILE" 2>/dev/null || stat -c %s "$DUMP_FILE") bytes"
   exit 1
 fi