fix: Add support for external PostgreSQL and Redis instances

Implements smart detection that allows users to provide external DATABASE_URL
or REDIS_URL. When external services are detected, internal instances are
automatically disabled to save resources. Maintains full backward compatibility
with existing setup

docker-compose.yml

@@ -53,6 +53,24 @@ services:
       # CONFIG_ENCRYPTION_KEY: "your-custom-encryption-key-here"
       # POSTGRES_PASSWORD: "your-custom-postgres-password-here"
 
+      # ========================================================================
+      # OPTIONAL: External PostgreSQL and Redis
+      # ========================================================================
+      # To use external PostgreSQL or Redis instances instead of the internal ones,
+      # uncomment and configure the appropriate URL(s):
+      #
+      # External PostgreSQL example:
+      # DATABASE_URL: "postgresql://username:password@postgres.example.com:5432/readmeabook"
+      #
+      # External Redis example:
+      # REDIS_URL: "redis://redis.example.com:6379"
+      # REDIS_URL: "redis://:password@redis.example.com:6379"  # With password
+      #
+      # Note: When using external services:
+      # - The internal PostgreSQL/Redis will NOT start (smart detection)
+      # - You do NOT need to mount ./pgdata or ./redis volumes
+      # - Ensure your external services are accessible from the container
+
       # ========================================================================
       # OPTIONAL: Rootless Podman Support
       # ========================================================================

docker/unified/entrypoint.sh

@@ -157,8 +157,33 @@ export PLEX_PRODUCT_NAME="${PLEX_PRODUCT_NAME:-ReadMeABook}"
 export LOG_LEVEL="${LOG_LEVEL:-info}"
 
 # ============================================================================
-# INITIALIZE POSTGRESQL
+# DETECT EXTERNAL SERVICES
 # ============================================================================
+# Check if user provided external DATABASE_URL or REDIS_URL
+USE_EXTERNAL_POSTGRES=false
+USE_EXTERNAL_REDIS=false
+
+if [ -n "$DATABASE_URL" ]; then
+    DB_HOST=$(echo "$DATABASE_URL" | sed -n 's|.*@\([^:/]*\).*|\1|p')
+    if [ "$DB_HOST" != "127.0.0.1" ] && [ "$DB_HOST" != "localhost" ]; then
+        USE_EXTERNAL_POSTGRES=true
+        echo "ℹ️  External PostgreSQL detected at $DB_HOST"
+    fi
+fi
+
+if [ -n "$REDIS_URL" ]; then
+    REDIS_HOST=$(echo "$REDIS_URL" | sed -n 's|redis://\([^:@]*@\)\?\([^:/]*\).*|\2|p')
+    if [ "$REDIS_HOST" != "127.0.0.1" ] && [ "$REDIS_HOST" != "localhost" ]; then
+        USE_EXTERNAL_REDIS=true
+        echo "ℹ️  External Redis detected at $REDIS_HOST"
+    fi
+fi
+
+# ============================================================================
+# INITIALIZE POSTGRESQL (only if using internal PostgreSQL)
+# ============================================================================
+if [ "$USE_EXTERNAL_POSTGRES" = "false" ]; then
+    echo "📦 Configuring internal PostgreSQL..."
     PGDATA="/var/lib/postgresql/data"
     PG_WAS_EMPTY=0
 
@@ -208,8 +233,12 @@ else
         chmod 700 "$PGDATA"
         chmod 775 /var/run/postgresql
     fi
+else
+    echo "⏭️  Skipping internal PostgreSQL setup (using external database)"
+fi
 
 # Redis directory - owned by redis user (remapped to PUID:PGID if set)
+if [ "$USE_EXTERNAL_REDIS" = "false" ]; then
     if ! chown -R redis:redis /var/lib/redis 2>/dev/null; then
         echo ""
         echo "❌ ERROR: Failed to set ownership on Redis directory"
@@ -218,6 +247,9 @@ if ! chown -R redis:redis /var/lib/redis 2>/dev/null; then
         exit 1
     fi
     chmod 770 /var/lib/redis
+else
+    echo "⏭️  Skipping internal Redis setup (using external Redis)"
+fi
 
 # App directories - owned by node user (remapped to PUID:PGID if set)
 # These need group write permissions for shared access
@@ -232,6 +264,8 @@ chmod 775 /app/config /app/cache
 
 echo "✅ Directory permissions configured"
 
+if [ "$USE_EXTERNAL_POSTGRES" = "false" ]; then
+    # Only initialize/setup PostgreSQL if using internal instance
     if [ ! -f "$PGDATA/PG_VERSION" ]; then
         PG_WAS_EMPTY=1
         echo "📦 Initializing PostgreSQL database..."
@@ -259,9 +293,9 @@ else
         echo "✅ PostgreSQL data directory already exists"
     fi
 
-# ============================================================================
+    # ========================================================================
     # START POSTGRESQL TEMPORARILY TO CREATE USER/DATABASE
-# ============================================================================
+    # ========================================================================
     echo "🔧 Starting PostgreSQL for setup..."
     su - postgres -c "/usr/lib/postgresql/16/bin/pg_ctl -D $PGDATA -w start -o '-c listen_addresses=127.0.0.1'"
 
@@ -302,13 +336,33 @@ else
         echo "✅ Database user and permissions verified"
     fi
 
+    # Stop PostgreSQL (supervisord will start it via wrapper)
+    echo "🔧 Stopping temporary PostgreSQL instance..."
+    su - postgres -c "/usr/lib/postgresql/16/bin/pg_ctl -D $PGDATA stop -m fast"
+fi
+
 # ============================================================================
 # SET ENVIRONMENT VARIABLES FOR APP
 # ============================================================================
+# Set DATABASE_URL and REDIS_URL based on whether we're using internal or external services
+if [ "$USE_EXTERNAL_POSTGRES" = "false" ]; then
     # URL-encode the password to handle special characters
     ENCODED_PASSWORD=$(urlencode "$POSTGRES_PASSWORD")
     export DATABASE_URL="postgresql://$POSTGRES_USER:$ENCODED_PASSWORD@127.0.0.1:5432/$POSTGRES_DB"
+    echo "✅ Using internal PostgreSQL (127.0.0.1:5432)"
+else
+    # DATABASE_URL already set by user - do not modify
+    echo "✅ Using external DATABASE_URL: ${DATABASE_URL%%@*}@***"
+fi
+
+if [ "$USE_EXTERNAL_REDIS" = "false" ]; then
     export REDIS_URL="redis://127.0.0.1:6379"
+    echo "✅ Using internal Redis (127.0.0.1:6379)"
+else
+    # REDIS_URL already set by user - do not modify
+    echo "✅ Using external REDIS_URL: ${REDIS_URL}"
+fi
+
 export NODE_ENV="production"
 export PORT="3030"
 export HOSTNAME="0.0.0.0"
@@ -335,16 +389,12 @@ EOF
 echo "✅ Environment configured"
 
 # ============================================================================
-# RUN PRISMA MIGRATIONS (while PostgreSQL is still running)
+# RUN PRISMA MIGRATIONS
 # ============================================================================
 echo "🔄 Running Prisma migrations..."
 cd /app
 su - node -c "cd /app && DATABASE_URL='$DATABASE_URL' npx prisma db push --skip-generate --accept-data-loss" || echo "⚠️  Migrations may have failed, continuing..."
 
-# Stop PostgreSQL (supervisord will start it)
-echo "🔧 Stopping temporary PostgreSQL instance..."
-su - postgres -c "/usr/lib/postgresql/16/bin/pg_ctl -D $PGDATA stop -m fast"
-
 # ============================================================================
 # DISPLAY STARTUP INFO
 # ============================================================================
@@ -361,8 +411,16 @@ if [ "$POSTGRES_PASSWORD" = "$(generate_secret)" ]; then
 fi
 echo ""
 echo "📊 Services starting:"
-echo "   - PostgreSQL (internal, user=postgres)"
+if [ "$USE_EXTERNAL_POSTGRES" = "false" ]; then
-echo "   - Redis (internal, UID:GID=${PUID:-102}:${PGID:-102})"
+    echo "   - PostgreSQL (internal, 127.0.0.1:5432)"
+else
+    echo "   - PostgreSQL (external - local instance disabled)"
+fi
+if [ "$USE_EXTERNAL_REDIS" = "false" ]; then
+    echo "   - Redis (internal, 127.0.0.1:6379, UID:GID=${PUID:-102}:${PGID:-102})"
+else
+    echo "   - Redis (external - local instance disabled)"
+fi
 echo "   - Next.js App (port 3030, UID:GID=${PUID:-1000}:${PGID:-1000})"
 if [ "${ROOTLESS_CONTAINER}" = "true" ]; then
     echo ""

docker/unified/postgres-start.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+# PostgreSQL startup wrapper for unified container
+# Smart supervisor: detects external PostgreSQL and sleeps instead of starting local instance
+#
+# Behavior:
+# - If DATABASE_URL points to external host (not 127.0.0.1/localhost), sleep infinity
+# - Otherwise, start local PostgreSQL instance
+
+set -e
+
+# Load environment from /etc/environment (set by entrypoint)
+if [ -f /etc/environment ]; then
+    set -a
+    source /etc/environment
+    set +a
+fi
+
+echo "[PostgreSQL] Checking for external database configuration..."
+
+# Extract host from DATABASE_URL
+# Format: postgresql://user:pass@host:port/db
+if [ -n "$DATABASE_URL" ]; then
+    # Extract the host part (between @ and :port or /)
+    DB_HOST=$(echo "$DATABASE_URL" | sed -n 's|.*@\([^:/]*\).*|\1|p')
+    
+    echo "[PostgreSQL] Detected DATABASE_URL host: $DB_HOST"
+    
+    # Check if host is external (not localhost or 127.0.0.1)
+    if [ "$DB_HOST" != "127.0.0.1" ] && [ "$DB_HOST" != "localhost" ]; then
+        echo "[PostgreSQL] ✅ External PostgreSQL detected at $DB_HOST"
+        echo "[PostgreSQL] Skipping local PostgreSQL startup - sleeping to keep supervisord happy"
+        exec sleep infinity
+    fi
+fi
+
+echo "[PostgreSQL] Starting local PostgreSQL server..."
+
+# Start PostgreSQL as postgres user
+exec /usr/lib/postgresql/16/bin/postgres -D /var/lib/postgresql/data

docker/unified/redis-start.sh

@@ -1,5 +1,11 @@
 #!/bin/bash
 # Redis startup wrapper for unified container
+# Smart supervisor: detects external Redis and sleeps instead of starting local instance
+#
+# Behavior:
+# - If REDIS_URL points to external host (not 127.0.0.1/localhost), sleep infinity
+# - Otherwise, start local Redis instance
+#
 # Uses gosu to ensure correct PUID:PGID for file operations
 #
 # Supports:
@@ -15,11 +21,30 @@ if [ -f /etc/environment ]; then
     set +a
 fi
 
+echo "[Redis] Checking for external Redis configuration..."
+
+# Extract host from REDIS_URL
+# Format: redis://host:port or redis://:password@host:port
+if [ -n "$REDIS_URL" ]; then
+    # Extract the host part (between :// or @, and :port or end)
+    REDIS_HOST=$(echo "$REDIS_URL" | sed -n 's|redis://\([^:@]*@\)\?\([^:/]*\).*|\2|p')
+    
+    echo "[Redis] Detected REDIS_URL host: $REDIS_HOST"
+    
+    # Check if host is external (not localhost or 127.0.0.1)
+    if [ "$REDIS_HOST" != "127.0.0.1" ] && [ "$REDIS_HOST" != "localhost" ]; then
+        echo "[Redis] ✅ External Redis detected at $REDIS_HOST"
+        echo "[Redis] Skipping local Redis startup - sleeping to keep supervisord happy"
+        exec sleep infinity
+    fi
+fi
+
+echo "[Redis] Starting local Redis server..."
+
 # Get PUID/PGID (default to redis user's current IDs if not set)
 PUID=${PUID:-$(id -u redis)}
 PGID=${PGID:-$(id -g redis)}
 
-echo "[Redis] Starting Redis server..."
 echo "[Redis] Process will run as UID:GID = $PUID:$PGID"
 
 # =============================================================================

docker/unified/supervisord.conf

@@ -7,7 +7,7 @@ loglevel=info
 pidfile=/var/run/supervisord.pid
 
 [program:postgresql]
-command=/usr/lib/postgresql/16/bin/postgres -D /var/lib/postgresql/data
+command=/app/postgres-start.sh
 user=postgres
 autostart=true
 autorestart=true

dockerfile.unified

@@ -115,6 +115,11 @@ COPY --chown=root:root docker/unified/redis-start.sh /app/redis-start.sh
 # Convert line endings and make executable
 RUN sed -i 's/\r$//' /app/redis-start.sh && chmod +x /app/redis-start.sh
 
+# Copy postgres startup wrapper
+COPY --chown=root:root docker/unified/postgres-start.sh /app/postgres-start.sh
+# Convert line endings and make executable
+RUN sed -i 's/\r$//' /app/postgres-start.sh && chmod +x /app/postgres-start.sh
+
 # Expose app port
 EXPOSE 3030