feat: robust automatic DB migration for Docker deployments

Backup before migration (pg_dump/SQLite copy), DB connection wait with
retries, idempotent prisma migrate deploy, old backup cleanup (keep 5),
and server refuses to start if migration fails.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/docker-entrypoint.sh

@@ -1,8 +1,149 @@
 #!/bin/sh
+# ============================================================
+# Memento Note — Docker Entrypoint
+# Automatic DB migration with backup, retry, and cleanup.
+# Safe for production: no data loss on image updates.
+# ============================================================
+
 set -e
 
-echo "Running Prisma migrations..."
-node ./node_modules/prisma/build/index.js migrate deploy
+BACKUP_DIR="/app/data/backups"
+MAX_BACKUPS=5
+DB_WAIT_RETRIES=30
+DB_WAIT_INTERVAL=2
+MIGRATE_TIMEOUT=120
+
+# --- Logging ---
+log()  { echo "[$(date '+%Y-%m-%d %H:%M:%S')] [entrypoint] $*"; }
+warn() { echo "[$(date '+%Y-%m-%d %H:%M:%S')] [entrypoint] WARNING: $*" >&2; }
+err()  { echo "[$(date '+%Y-%m-%d %H:%M:%S')] [entrypoint] ERROR: $*" >&2; }
+
+# --- Detect database type ---
+DB_TYPE="unknown"
+case "$DATABASE_URL" in
+  postgres://*|postgresql://*) DB_TYPE="postgres" ;;
+  file:*)                       DB_TYPE="sqlite" ;;
+esac
+log "Database type: $DB_TYPE"
+
+# --- Wait for database to be reachable ---
+wait_for_db() {
+  if [ "$DB_TYPE" = "sqlite" ]; then
+    log "SQLite — no connection check needed."
+    return 0
+  fi
+
+  log "Waiting for database connection..."
+  i=0
+  while [ "$i" -lt "$DB_WAIT_RETRIES" ]; do
+    if node -e "
+      const m = process.env.DATABASE_URL.match(/@([^:\/]+):(\d+)/);
+      if (!m) process.exit(1);
+      const net = require('net');
+      const s = net.createConnection(parseInt(m[2]), m[1], () => { s.end(); process.exit(0); });
+      s.setTimeout(3000, () => { s.destroy(); process.exit(1); });
+      s.on('error', () => process.exit(1));
+    " 2>/dev/null; then
+      log "Database is reachable."
+      return 0
+    fi
+    i=$((i + 1))
+    log "  Attempt $i/$DB_WAIT_RETRIES — retrying in ${DB_WAIT_INTERVAL}s..."
+    sleep "$DB_WAIT_INTERVAL"
+  done
+
+  err "Database unreachable after $((DB_WAIT_RETRIES * DB_WAIT_INTERVAL)) seconds. Aborting."
+  exit 1
+}
+
+# --- Create backup before migration ---
+create_backup() {
+  mkdir -p "$BACKUP_DIR"
+  ts=$(date '+%Y%m%d_%H%M%S')
+
+  case "$DB_TYPE" in
+    postgres)
+      backup_file="$BACKUP_DIR/pre_migrate_${ts}.sql.gz"
+      log "Creating PostgreSQL backup: $backup_file"
+      if command -v pg_dump >/dev/null 2>&1; then
+        if pg_dump --no-owner --no-privileges --format=plain "$DATABASE_URL" 2>/dev/null | gzip > "$backup_file" 2>/dev/null; then
+          size=$(du -h "$backup_file" | cut -f1)
+          log "Backup created successfully ($size)"
+        else
+          warn "pg_dump failed. Continuing without backup."
+          rm -f "$backup_file"
+        fi
+      else
+        warn "pg_dump not available. Skipping PostgreSQL backup."
+        warn "Install postgresql-client in the Docker image for automatic backups."
+      fi
+      ;;
+    sqlite)
+      db_path="${DATABASE_URL#file:}"
+      # Handle relative paths
+      case "$db_path" in
+        /*) ;;
+        *)  db_path="/app/$db_path" ;;
+      esac
+      backup_file="$BACKUP_DIR/pre_migrate_${ts}.sqlite"
+      if [ -f "$db_path" ]; then
+        log "Creating SQLite backup: $backup_file"
+        cp "$db_path" "$backup_file"
+        size=$(du -h "$backup_file" | cut -f1)
+        log "Backup created successfully ($size)"
+      else
+        warn "SQLite file not found at $db_path — skipping backup (first run)."
+      fi
+      ;;
+    *)
+      warn "Unknown database type '$DB_TYPE'. Skipping backup."
+      ;;
+  esac
+}
+
+# --- Clean up old backups (keep last N) ---
+cleanup_old_backups() {
+  count=$(ls -1 "$BACKUP_DIR"/pre_migrate_* 2>/dev/null | wc -l)
+  if [ "$count" -gt "$MAX_BACKUPS" ]; then
+    to_remove=$((count - MAX_BACKUPS))
+    log "Cleaning up $to_remove old backup(s), keeping last $MAX_BACKUPS..."
+    ls -1t "$BACKUP_DIR"/pre_migrate_* 2>/dev/null | tail -n "$to_remove" | xargs rm -f
+  fi
+}
+
+# --- Run Prisma migrations ---
+run_migrations() {
+  log "Running Prisma migrations..."
+  if timeout "$MIGRATE_TIMEOUT" node ./node_modules/prisma/build/index.js migrate deploy 2>&1; then
+    log "Migrations applied successfully."
+    return 0
+  else
+    exit_code=$?
+    err "Migration failed (exit code $exit_code)."
+    return "$exit_code"
+  fi
+}
+
+# ============================================================
+# Main flow
+# ============================================================
+
+# Step 1: Wait for database
+wait_for_db
+
+# Step 2: Backup
+create_backup
+
+# Step 3: Cleanup old backups
+cleanup_old_backups
+
+# Step 4: Migrate
+if ! run_migrations; then
+  err "Migration failed — server will NOT start to prevent data corruption."
+  err "A backup was saved in $BACKUP_DIR (if backup was successful)."
+  err "To restore: gunzip the .sql.gz file, then: psql DATABASE_URL < backup.sql"
+  exit 1
+fi
 
 # Background scheduler: call /api/cron/agents every 5 minutes
 (
@@ -22,5 +163,6 @@ node ./node_modules/prisma/build/index.js migrate deploy
   done
 ) &
 
-echo "Starting server..."
+# Step 5: Start server
+log "Starting server..."
 exec node server.js