startup.sh

#!/bin/bash

# Strict error handling
set -euo pipefail

# Load environment variables
if [ -f .env ]; then
  source .env
fi

# Validate required environment variables
if [ -z "$DATABASE_URL" ]; then
  echo "Error: DATABASE_URL is not set" >&2
  exit 1
fi

# Set default values for optional variables
REDIS_URL=${REDIS_URL:-"redis://localhost:6379"}
NODE_ENV=${NODE_ENV:-"development"}

# Define script variables
PROJECT_ROOT=$(pwd)
LOG_FILE="$PROJECT_ROOT/logs/startup.log"
PID_FILE="$PROJECT_ROOT/logs/pids.txt"
DATABASE_TIMEOUT=30
BACKEND_TIMEOUT=30
FRONTEND_TIMEOUT=30
HEALTH_CHECK_INTERVAL=5

# Logging functions
log_info() {
  echo "$(date +"%Y-%m-%d %H:%M:%S") INFO: $@" >> "$LOG_FILE"
}

log_error() {
  echo "$(date +"%Y-%m-%d %H:%M:%S") ERROR: $@" >&2 >> "$LOG_FILE"
}

# Cleanup function
cleanup() {
  log_info "Cleaning up..."
  rm -f "$PID_FILE"
  # ... (Stop services if needed)
}

# Dependency checks
check_dependencies() {
  log_info "Checking dependencies..."
  # ... (Check for required tools, like npm, docker, etc.)
}

# Health check functions
check_port() {
  local port=$1
  nc -z localhost "$port" > /dev/null 2>&1
  if [ $? -eq 0 ]; then
    return 0
  else
    return 1
  fi
}

wait_for_service() {
  local service_name=$1
  local port=$2
  local timeout=$3
  local attempts=0
  log_info "Waiting for $service_name on port $port..."
  while [ "$attempts" -lt "$timeout" ]; do
    if check_port "$port"; then
      log_info "$service_name is available."
      return 0
    fi
    sleep "$HEALTH_CHECK_INTERVAL"
    attempts=$((attempts + 1))
  done
  log_error "Timeout waiting for $service_name."
  exit 1
}

verify_service() {
  local service_name=$1
  local url=$2
  log_info "Verifying $service_name at $url..."
  # ... (Implement service health check logic)
}

# Service management functions
start_database() {
  log_info "Starting PostgreSQL database..."
  docker run -d --name fitness-tracker-db -e POSTGRES_USER=user -e POSTGRES_PASSWORD=password -e POSTGRES_DB=database_name -p 5432:5432 postgres:latest
  wait_for_service "PostgreSQL" 5432 "$DATABASE_TIMEOUT"
}

start_backend() {
  log_info "Starting backend server..."
  npm start &
  wait_for_service "Backend" 3000 "$BACKEND_TIMEOUT"
}

start_frontend() {
  log_info "Starting frontend service..."
  npm run dev &
  wait_for_service "Frontend" 3000 "$FRONTEND_TIMEOUT"
}

store_pid() {
  log_info "Storing process IDs..."
  # ... (Save process IDs to PID_FILE)
}

# Trap signals
trap cleanup EXIT ERR

# Main execution flow
check_dependencies
start_database
start_backend
# ... (Start other services, if needed)
start_frontend
store_pid

log_info "Fitness Tracker MVP startup complete."