java21-template/init_and_start.sh

#!/bin/bash

# Java Service Template - Initialization and Startup Script
# This script initializes the database, 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}"
}

# Configuration
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 initialization..."

# Function to check if PostgreSQL is running
check_postgres() {
    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
}

# 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, skipping creation."
        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 establish Flyway baseline
establish_flyway_baseline() {
    echo_color $YELLOW "Establishing Flyway baseline..."
    
    # Check if flyway schema history table exists
    if PGPASSWORD="$DB_PASS" psql -h "$DB_HOST" -p "$DB_PORT" -d "$DB_NAME" -U "$DB_USER" -tAc "SELECT EXISTS (SELECT FROM information_schema.tables WHERE table_schema = 'public' AND table_name = 'flyway_schema_history');" | grep -q 't'; then
        echo_color $GREEN "Flyway schema history table already exists, skipping baseline."
        return 0
    fi
    
    # Run the application with Flyway baseline enabled
    echo_color $YELLOW "Running application to establish Flyway baseline..."
    
    # Temporarily set baseline on migrate to true
    JAVA_OPTS="-Dspring.flyway.baseline-on-migrate=true -Dspring.flyway.baseline-version=0 -Dspring.profiles.active=dev"
    JAVA_OPTS="$JAVA_OPTS -DDB_HOST=$DB_HOST -DDB_PORT=$DB_PORT -DDB_NAME=$DB_NAME -DDB_USER=$DB_USER -DDB_PASS=$DB_PASS"
    
    # Run the application briefly to establish baseline
    timeout 30s java $JAVA_OPTS -jar $APP_JAR || true
    
    echo_color $GREEN "Flyway baseline established."
}

# Function to run migrations
run_migrations() {
    echo_color $YELLOW "Running database migrations..."
    
    # Run the application to apply migrations
    JAVA_OPTS="-Dspring.profiles.active=dev"
    JAVA_OPTS="$JAVA_OPTS -DDB_HOST=$DB_HOST -DDB_PORT=$DB_PORT -DDB_NAME=$DB_NAME -DDB_USER=$DB_USER -DDB_PASS=$DB_PASS"
    
    # Run the application briefly to apply migrations
    timeout 30s java $JAVA_OPTS -jar $APP_JAR || true
    
    echo_color $GREEN "Database migrations applied."
}

# 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 start the application
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 in the background
    JAVA_OPTS="-Dspring.profiles.active=dev"
    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"
    java $JAVA_OPTS -jar $APP_JAR &
    
    APP_PID=$!
    echo $APP_PID > app.pid
    echo_color $GREEN "Application started with PID: $APP_PID"
    echo_color $GREEN "Application is available at: http://localhost:8080"
    echo_color $GREEN "Actuator endpoints available at: http://localhost:8080/actuator"
    
    # Wait for the application to finish
    wait $APP_PID
}

# Main execution
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..."
    create_database
    
    echo_color $YELLOW "Step 4: Establishing Flyway baseline..."
    establish_flyway_baseline
    
    echo_color $YELLOW "Step 5: Running migrations..."
    run_migrations
    
    echo_color $YELLOW "Step 6: Starting application..."
    start_application
}

# Parse command line arguments
case "${1:-full}" in
    "init-only")
        echo_color $YELLOW "Initializing database and establishing Flyway baseline only..."
        check_postgres
        create_database
        establish_flyway_baseline
        run_migrations
        echo_color $GREEN "Database initialization completed!"
        ;;
    "start-only")
        echo_color $YELLOW "Starting application only..."
        if [ ! -f "$APP_JAR" ]; then
            echo_color $RED "Application JAR not found. Please build first or run 'full'."
            exit 1
        fi
        start_application
        ;;
    "build-only")
        echo_color $YELLOW "Building application only..."
        build_application
        ;;
    "full"|"")
        main
        ;;
    *)
        echo_color $RED "Usage: $0 [full|init-only|start-only|build-only]"
        echo_color $YELLOW "  full (default): Initialize database and start application"
        echo_color $YELLOW "  init-only: Initialize database and establish Flyway baseline only"
        echo_color $YELLOW "  start-only: Start application only (requires built JAR)"
        echo_color $YELLOW "  build-only: Build application only"
        exit 1
        ;;
esac