entrypoint.sh

#!/bin/sh
set -e

# Production entrypoint script
# Handles initialization, secrets, and graceful startup

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

log() {
    printf "%s[%s] INFO:%s %s\n" "$GREEN" "$(date +'%Y-%m-%d %H:%M:%S')" "$NC" "$1"
}

warn() {
    printf "%s[%s] WARN:%s %s\n" "$YELLOW" "$(date +'%Y-%m-%d %H:%M:%S')" "$NC" "$1"
}

error() {
    printf "%s[%s] ERROR:%s %s\n" "$RED" "$(date +'%Y-%m-%d %H:%M:%S')" "$NC" "$1"
}

# Function to handle graceful shutdown
graceful_shutdown() {
    log "Received shutdown signal, performing graceful shutdown..."
    if [ -n "$SERVER_PID" ]; then
        kill -TERM "$SERVER_PID" 2>/dev/null || true
        wait "$SERVER_PID" 2>/dev/null || true
    fi
    log "Graceful shutdown completed"
    exit 0
}

# Set up signal handlers
trap graceful_shutdown TERM INT

# Validate required environment variables
validate_env() {
    required_vars="PORT"
    missing_vars=""

    for var in $required_vars; do
        eval "value=\$$var"
        if [ -z "$value" ]; then
            missing_vars="$missing_vars $var"
        fi
    done

    if [ -n "$missing_vars" ]; then
        error "Missing required environment variables:$missing_vars"
        exit 1
    fi
}

# Initialize Google Cloud credentials if provided
init_gcp_credentials() {
    if [ -n "$GOOGLE_CREDENTIALS" ]; then
        log "Setting up Google Cloud credentials..."
        printf "%s" "$GOOGLE_CREDENTIALS" > /tmp/service-account-key.json
        export GOOGLE_APPLICATION_CREDENTIALS="/tmp/service-account-key.json"

        if command -v jq >/dev/null 2>&1; then
            echo "$GOOGLE_CREDENTIALS" | jq empty 2>/dev/null || warn "Google credentials may not be valid JSON"
        else
            warn "jq not installed, cannot validate JSON"
        fi
    elif [ -n "$GOOGLE_APPLICATION_CREDENTIALS" ] && [ -f "$GOOGLE_APPLICATION_CREDENTIALS" ]; then
        log "Using existing Google Cloud credentials file: $GOOGLE_APPLICATION_CREDENTIALS"
    else
        warn "No Google Cloud credentials provided"
    fi
}

# Health check function
health_check() {
    max_attempts=30
    attempt=1

    log "Waiting for application to be ready..."

    while [ "$attempt" -le "$max_attempts" ]; do
        if curl -sf "http://localhost:${PORT}/health" >/dev/null 2>&1; then
            log "Application is ready and healthy"
            return 0
        fi

        log "Health check attempt $attempt/$max_attempts failed, retrying in 2s..."
        sleep 2
        attempt=$((attempt + 1))
    done

    error "Application failed to become healthy after $max_attempts attempts"
    return 1
}

# Pre-flight checks
preflight_checks() {
    log "Running pre-flight checks..."

    required_bins="server"
    for bin in $required_bins; do
        if ! command -v "$bin" >/dev/null 2>&1; then
            error "Required binary not found: $bin"
            exit 1
        fi
    done

    openmvg_bins="openMVG_main_SfMInit_ImageListing openMVG_main_ComputeFeatures"
    for bin in $openmvg_bins; do
        if ! command -v "$bin" >/dev/null 2>&1; then
            warn "OpenMVG binary not found: $bin"
        fi
    done

    log "Pre-flight checks completed successfully"
}

# Main execution
main() {
    log "Starting application with PID: $$"
    log "Running as user: $(whoami)"
    log "Working directory: $(pwd)"
    log "Environment: ${GIN_MODE:-development}"

    # Run initialization steps
    validate_env
    init_gcp_credentials
    preflight_checks

    case "${1:-server}" in
        "server")
            log "Starting Go server on port $PORT..."
            /usr/local/bin/server &
            SERVER_PID=$!

            sleep 5

            if command -v curl >/dev/null 2>&1; then
                health_check &
            fi

            wait "$SERVER_PID"
            ;;
        "health")
            curl -f "http://localhost:${PORT}/health"
            ;;
        *)
            log "Executing command: $*"
            exec "$@"
            ;;
    esac
}

main "$@"