java21-template/start_app.sh

#!/bin/bash

# Java Service Template - Quick Start Script
# Initializes database 'java_template', establishes Flyway baseline, and starts the application

set -e  # Exit immediately if a command exits with a non-zero status

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

echo_color() {
    local color=$1
    local message=$2
    echo -e "${color}${message}${NC}"
}

# Check if another instance is already running
if pgrep -f "java.*tmpl-api.*SNAPSHOT.jar" > /dev/null; then
    echo_color $RED "Another instance of the application is already running!"
    echo_color $YELLOW "Please stop the existing process before starting a new one."
    exit 1
fi

# Configuration - Use environment variables with defaults
PORT="${PORT:-48080}"
DB_NAME="${DB_NAME:-java_template}"
DB_USER="${DB_USER:-postgres}"
DB_PASS="${DB_PASS:-postgres}"
DB_HOST="${DB_HOST:-localhost}"
DB_PORT="${DB_PORT:-5432}"

APP_JAR="tmpl-api/target/tmpl-api-0.1.0-SNAPSHOT.jar"

echo_color $YELLOW "Starting Java Service Template setup..."
echo_color $YELLOW "Using port: $PORT"

# Function to check if PostgreSQL is running
check_postgres() {
    echo_color $YELLOW "Checking PostgreSQL connectivity..."

    if ! command -v psql &> /dev/null; then
        echo_color $RED "psql command not found. Please install PostgreSQL client."
        exit 1
    fi

    if ! pg_isready -h "$DB_HOST" -p "$DB_PORT" 2>/dev/null; then
        echo_color $RED "PostgreSQL server is not running at $DB_HOST:$DB_PORT"
        echo_color $YELLOW "Please start PostgreSQL server before running this script."
        exit 1
    fi

    echo_color $GREEN "✓ PostgreSQL is accessible"
}

# Function to create database
create_database() {
    echo_color $YELLOW "Creating database: $DB_NAME"

    # Check if database already exists
    if PGPASSWORD="$DB_PASS" psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -lqt | cut -d \| -f 1 | grep -qw "$DB_NAME"; then
        echo_color $GREEN "✓ Database $DB_NAME already exists"
        return 0
    fi

    # Create database
    PGPASSWORD="$DB_PASS" createdb -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -O "$DB_USER" "$DB_NAME"
    echo_color $GREEN "✓ Database $DB_NAME created successfully"
}

# Function to build the application
build_application() {
    echo_color $YELLOW "Building the application..."

    if [ ! -f "pom.xml" ]; then
        echo_color $RED "✗ Pom.xml not found in current directory!"
        exit 1
    fi

    mvn clean package -DskipTests

    if [ ! -f "$APP_JAR" ]; then
        echo_color $RED "✗ Application JAR not found at $APP_JAR after build!"
        exit 1
    fi

    echo_color $GREEN "✓ Application built successfully"
}

# Function to establish Flyway baseline and run migrations
setup_flyway() {
    echo_color $YELLOW "Setting up Flyway migrations..."

    # Run the application once to let Flyway handle the database setup
    # This will create the flyway_schema_history table and apply migrations
    JAVA_OPTS="-Dspring.profiles.active=dev,redis -Dspring.main.allow-bean-definition-overriding=true"
    JAVA_OPTS="$JAVA_OPTS -DDB_HOST=$DB_HOST -DDB_PORT=$DB_PORT -DDB_NAME=$DB_NAME -DDB_USER=$DB_USER -DDB_PASS=$DB_PASS"

    echo_color $YELLOW "Running application to initialize database with Flyway..."

    # Run the application briefly to let Flyway do its job
    # Use a random port to avoid conflicts and ensure quick startup/shutdown
    timeout 30s java $JAVA_OPTS -Dserver.port=0 -Dmanagement.server.port=0 -jar $APP_JAR || true
    # The || true ensures the script continues even if timeout kills the process

    echo_color $GREEN "✓ Flyway setup completed (baseline and migrations applied)"
}

# Function to start the application properly
start_application() {
    echo_color $YELLOW "Starting the application..."

    # Set environment variables for the application
    export DB_HOST=$DB_HOST
    export DB_PORT=$DB_PORT
    export DB_NAME=$DB_NAME
    export DB_USER=$DB_USER
    export DB_PASS=$DB_PASS

    # Start the application with the specified port
    JAVA_OPTS="-Dserver.port=$PORT -Dmanagement.server.port=$PORT"
    JAVA_OPTS="$JAVA_OPTS -Dspring.profiles.active=dev,redis -Dspring.main.allow-bean-definition-overriding=true"
    JAVA_OPTS="$JAVA_OPTS -DDB_HOST=$DB_HOST -DDB_PORT=$DB_PORT -DDB_NAME=$DB_NAME -DDB_USER=$DB_USER -DDB_PASS=$DB_PASS"

    echo_color $GREEN "✓ Starting application with command: java $JAVA_OPTS -jar $APP_JAR"
    echo_color $GREEN "✓ Application will be available at: http://localhost:$PORT"
    echo_color $GREEN "✓ Health endpoint: http://localhost:$PORT/actuator/health"

    java $JAVA_OPTS -jar $APP_JAR
}

# Main execution sequence
main() {
    echo_color $YELLOW "=== Step 1: Checking prerequisites ==="
    check_postgres

    echo_color $YELLOW "=== Step 2: Building application ==="
    build_application

    echo_color $YELLOW "=== Step 3: Creating database '$DB_NAME' ==="
    create_database

    echo_color $YELLOW "=== Step 4: Setting up Flyway (baseline and migrations) ==="
    setup_flyway

    echo_color $YELLOW "=== Step 5: Starting application ==="
    start_application
}

# Run the main function
main