provision-cloud.sh

#!/bin/bash

# This script provisions the cloud infrastructure for n8n on GCP.

# Exit on error
set -e

# --- Configuration ---

# Project Selection
echo "Fetching your GCP projects..."
PROJECTS=$(gcloud projects list --format="value(projectId)" 2>/dev/null)

if [ -z "$PROJECTS" ]; then
    echo "No projects found or error fetching projects."
    read -p "Enter your GCP Project ID manually: " PROJECT_ID
else
    PROJECT_ARRAY=($PROJECTS)
    if [ ${#PROJECT_ARRAY[@]} -eq 1 ]; then
        PROJECT_ID="${PROJECT_ARRAY[0]}"
        echo "Using project: $PROJECT_ID"
    else
        echo ""
        echo "Available GCP Projects:"
        select PROJECT_ID in "${PROJECT_ARRAY[@]}"; do
            if [ -n "$PROJECT_ID" ]; then
                break
            else
                echo "Invalid selection. Please try again."
            fi
        done
    fi
fi

# Set project first to ensure subsequent commands work
gcloud config set project "$PROJECT_ID" --quiet

# Region Selection
echo ""
echo "Fetching available GCP regions..."
REGIONS=$(gcloud compute regions list --format="value(name)" 2>/dev/null | sort)

if [ -z "$REGIONS" ]; then
    echo "Error fetching regions. Please ensure Compute Engine API is enabled."
    read -p "Enter the GCP Region manually (e.g., us-central1): " REGION
else
    REGION_ARRAY=($REGIONS)
    echo ""
    echo "Select a GCP Region (recommended: regions close to your users):"
    echo "Tip: Europe regions start with 'europe-', US with 'us-', Asia with 'asia-'"
    echo ""
    select REGION in "${REGION_ARRAY[@]}"; do
        if [ -n "$REGION" ]; then
            break
        else
            echo "Invalid selection. Please try again."
        fi
    done
fi

# Zone Selection
echo ""
echo "Fetching available zones in $REGION..."
ZONES=$(gcloud compute zones list --filter="region:$REGION" --format="value(name)" 2>/dev/null | sort)

if [ -z "$ZONES" ]; then
    echo "Error fetching zones for region $REGION."
    read -p "Enter the GCP Zone manually (e.g., $REGION-a): " ZONE
else
    ZONE_ARRAY=($ZONES)
    echo ""
    echo "Select a Zone in $REGION:"
    select ZONE in "${ZONE_ARRAY[@]}"; do
        if [ -n "$ZONE" ]; then
            break
        else
            echo "Invalid selection. Please try again."
        fi
    done
fi

# Machine Type Selection
echo ""
echo "Select a machine type for your n8n instance:"
echo ""
echo "Machine Type          vCPUs  Memory  Est. Cost/Month  Recommended For"
echo "--------------------------------------------------------------------------------"
echo "1) e2-micro            0.25   1 GB    ~$7-9           Testing only (may be slow)"
echo "2) e2-small            0.5    2 GB    ~$14-16         Light usage, few workflows"
echo "3) e2-medium           1      4 GB    ~$24-30         Recommended: Most users"
echo "4) e2-standard-2       2      8 GB    ~$49-60         Heavy usage, many workflows"
echo "5) e2-standard-4       4     16 GB    ~$97-120        Very heavy usage, complex workflows"
echo "6) n2-standard-2       2      8 GB    ~$73-90         Better performance than e2"
echo "7) n2-standard-4       4     16 GB    ~$146-180       High performance needs"
echo ""
echo "Note: Costs vary by region. Prices shown are estimates for US/Europe regions."
echo ""

PS3="Select machine type (1-7) [default=3]: "
MACHINE_TYPES=("e2-micro" "e2-small" "e2-medium" "e2-standard-2" "e2-standard-4" "n2-standard-2" "n2-standard-4")
MACHINE_NAMES=("e2-micro (0.25 vCPU, 1GB)" "e2-small (0.5 vCPU, 2GB)" "e2-medium (1 vCPU, 4GB)" "e2-standard-2 (2 vCPU, 8GB)" "e2-standard-4 (4 vCPU, 16GB)" "n2-standard-2 (2 vCPU, 8GB)" "n2-standard-4 (4 vCPU, 16GB)")

select opt in "${MACHINE_NAMES[@]}"; do
    case $REPLY in
        1) MACHINE_TYPE="${MACHINE_TYPES[0]}"; break;;
        2) MACHINE_TYPE="${MACHINE_TYPES[1]}"; break;;
        3) MACHINE_TYPE="${MACHINE_TYPES[2]}"; break;;
        4) MACHINE_TYPE="${MACHINE_TYPES[3]}"; break;;
        5) MACHINE_TYPE="${MACHINE_TYPES[4]}"; break;;
        6) MACHINE_TYPE="${MACHINE_TYPES[5]}"; break;;
        7) MACHINE_TYPE="${MACHINE_TYPES[6]}"; break;;
        "") MACHINE_TYPE="e2-medium"; echo "Using default: e2-medium"; break;;
        *) echo "Invalid selection. Please try again.";;
    esac
done

# Domain Name
echo ""
read -p "Enter the domain name for n8n (e.g., n8n.example.com): " DOMAIN_NAME

# Validate domain name
if [ -z "$DOMAIN_NAME" ]; then
    echo "Error: Domain name cannot be empty."
    exit 1
fi

# Basic domain name validation
if ! echo "$DOMAIN_NAME" | grep -qE '^[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(\.[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*\.[a-zA-Z]{2,}$'; then
    echo "Error: '$DOMAIN_NAME' does not appear to be a valid domain name."
    echo "Please use a format like: n8n.example.com"
    exit 1
fi

# Display selected configuration
echo ""
echo "========================================="
echo "Deployment Configuration:"
echo "========================================="
echo "Project:       $PROJECT_ID"
echo "Region:        $REGION"
echo "Zone:          $ZONE"
echo "Machine Type:  $MACHINE_TYPE"
echo "Domain:        $DOMAIN_NAME"
echo "========================================="
echo ""
read -p "Continue with this configuration? (y/N): " confirm

if [ "$confirm" != "y" ] && [ "$confirm" != "Y" ]; then
    echo "Deployment cancelled."
    exit 0
fi

INSTANCE_NAME="n8n-instance"
STATIC_IP_NAME="n8n-static-ip"
FIREWALL_RULE_NAME="allow-web-traffic"
NETWORK_TAG="n8n-web"

# --- Helper Functions ---
check_dns_propagation() {
    local domain=$1
    local expected_ip=$2
    local max_attempts=10
    local attempt=1

    echo "Checking DNS propagation for $domain..."

    while [ $attempt -le $max_attempts ]; do
        echo "Attempt $attempt/$max_attempts: Checking if $domain resolves to $expected_ip..."

        # Try to resolve the domain
        resolved_ip=$(dig +short "$domain" @8.8.8.8 | tail -n1)

        if [ -z "$resolved_ip" ]; then
            resolved_ip=$(nslookup "$domain" 8.8.8.8 2>/dev/null | grep -A1 "Name:" | tail -n1 | awk '{print $2}')
        fi

        if [ "$resolved_ip" = "$expected_ip" ]; then
            echo "✓ DNS propagation confirmed! $domain resolves to $expected_ip"
            return 0
        fi

        if [ $attempt -lt $max_attempts ]; then
            echo "DNS not propagated yet (currently resolves to: ${resolved_ip:-'nothing'}). Waiting 10 seconds..."
            sleep 10
        fi

        attempt=$((attempt + 1))
    done

    echo "⚠ Warning: DNS may not be fully propagated yet."
    echo "Current resolution: ${resolved_ip:-'no result'}"
    echo "Expected: $expected_ip"
    read -p "Continue anyway? (y/N): " continue_anyway

    if [ "$continue_anyway" != "y" ] && [ "$continue_anyway" != "Y" ]; then
        echo "Deployment cancelled. Please wait for DNS to propagate and try again."
        exit 1
    fi
}

# --- GCP CLI Checks ---
if ! command -v gcloud &> /dev/null
then
    echo "gcloud CLI not found. Please install it and configure it."
    exit 1
fi

# --- Provisioning ---

echo ""
echo "Configuring gcloud CLI..."
gcloud config set compute/region "$REGION" --quiet
gcloud config set compute/zone "$ZONE" --quiet

# Check if static IP already exists
if gcloud compute addresses describe "$STATIC_IP_NAME" --region="$REGION" &>/dev/null; then
    echo "Static IP '$STATIC_IP_NAME' already exists. Using existing IP..."
    STATIC_IP=$(gcloud compute addresses describe "$STATIC_IP_NAME" --region="$REGION" --format='get(address)')
else
    echo "Reserving a static IP address..."
    gcloud compute addresses create "$STATIC_IP_NAME" --region="$REGION"
    STATIC_IP=$(gcloud compute addresses describe "$STATIC_IP_NAME" --region="$REGION" --format='get(address)')
fi

# Check if firewall rule already exists
if gcloud compute firewall-rules describe "$FIREWALL_RULE_NAME" &>/dev/null; then
    echo "Firewall rule '$FIREWALL_RULE_NAME' already exists. Skipping creation..."
else
    echo "Creating firewall rules..."
    gcloud compute firewall-rules create "$FIREWALL_RULE_NAME" \
        --allow tcp:80,tcp:443,tcp:22 \
        --source-ranges=0.0.0.0/0 \
        --target-tags="$NETWORK_TAG"
fi

# Check if instance already exists
if gcloud compute instances describe "$INSTANCE_NAME" --zone="$ZONE" &>/dev/null; then
    echo "Error: Instance '$INSTANCE_NAME' already exists in zone '$ZONE'."
    echo "Please delete the existing instance or choose a different name."
    exit 1
fi

echo "Creating the Compute Engine instance..."
gcloud compute instances create "$INSTANCE_NAME" \
    --machine-type="$MACHINE_TYPE" \
    --image-family=ubuntu-2204-lts \
    --image-project=ubuntu-os-cloud \
    --address="$STATIC_IP_NAME" \
    --tags="$NETWORK_TAG"

# --- DNS Instructions ---
echo "-----------------------------------------------------"
echo "Action Required:"
echo "Please create a DNS A record for '$DOMAIN_NAME' pointing to the IP address: $STATIC_IP"
echo "-----------------------------------------------------"
read -p "Press [Enter] to continue after updating the DNS record..."

# Check DNS propagation
check_dns_propagation "$DOMAIN_NAME" "$STATIC_IP"

# --- Remote Configuration ---
echo "Waiting for the instance to be ready..."
sleep 30 # Wait for the instance to boot up

echo "Copying setup files to the instance..."
gcloud compute scp --recurse ./templates "$INSTANCE_NAME":~
gcloud compute scp ./setup-instance.sh "$INSTANCE_NAME":~

echo "Executing the setup script on the instance..."
gcloud compute ssh "$INSTANCE_NAME" --command="./setup-instance.sh \"$DOMAIN_NAME\""

echo "-----------------------------------------------------"
echo "Deployment complete!"
echo "You can now access your n8n instance at: https://$DOMAIN_NAME"
echo "-----------------------------------------------------"