Get started with Cloud Map service discovery

The following code example shows how to:

• Create a public DNS namespace with Route 53 hosted zone integration

• Create services discoverable via DNS queries and API calls

• Register service instances with different discovery configurations

• Discover services using both DNS queries and Cloud Map API

• Verify service discovery using dig command and API calls

• Clean up resources in proper order (instances, services, namespace)

Bash

AWS CLI with Bash script

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Sample developer tutorials repository.

#!/bin/bash

# AWS Cloud Map Private Namespace Tutorial Script
# This script demonstrates how to use AWS Cloud Map for service discovery
# with DNS queries and API calls

# Exit on error
set -e

# Configuration
REGION="us-east-2"
NAMESPACE_NAME="cloudmap-tutorial.com"
LOG_FILE="cloudmap-tutorial.log"
CREATOR_REQUEST_ID=$(date +%s)

# Function to log messages
log() {
    local message="$1"
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $message" | tee -a "$LOG_FILE"
}

# Function to check operation status
check_operation() {
    local operation_id="$1"
    local status=""
    
    log "Checking operation status for $operation_id..."
    
    while [[ "$status" != "SUCCESS" ]]; do
        sleep 5
        status=$(aws servicediscovery get-operation \
            --operation-id "$operation_id" \
            --region "$REGION" \
            --query "Operation.Status" \
            --output text)
        
        log "Operation status: $status"
        
        if [[ "$status" == "FAIL" ]]; then
            log "Operation failed. Exiting."
            exit 1
        fi
    done
    
    log "Operation completed successfully."
}

# Function to clean up resources
cleanup() {
    log "Starting cleanup process..."
    
    if [[ -n "$FIRST_INSTANCE_ID" ]]; then
        log "Deregistering first service instance..."
        aws servicediscovery deregister-instance \
            --service-id "$PUBLIC_SERVICE_ID" \
            --instance-id "$FIRST_INSTANCE_ID" \
            --region "$REGION" || log "Failed to deregister first instance"
    fi
    
    if [[ -n "$SECOND_INSTANCE_ID" ]]; then
        log "Deregistering second service instance..."
        aws servicediscovery deregister-instance \
            --service-id "$BACKEND_SERVICE_ID" \
            --instance-id "$SECOND_INSTANCE_ID" \
            --region "$REGION" || log "Failed to deregister second instance"
    fi
    
    if [[ -n "$PUBLIC_SERVICE_ID" ]]; then
        log "Deleting public service..."
        aws servicediscovery delete-service \
            --id "$PUBLIC_SERVICE_ID" \
            --region "$REGION" || log "Failed to delete public service"
    fi
    
    if [[ -n "$BACKEND_SERVICE_ID" ]]; then
        log "Deleting backend service..."
        aws servicediscovery delete-service \
            --id "$BACKEND_SERVICE_ID" \
            --region "$REGION" || log "Failed to delete backend service"
    fi
    
    if [[ -n "$NAMESPACE_ID" ]]; then
        log "Deleting namespace..."
        aws servicediscovery delete-namespace \
            --id "$NAMESPACE_ID" \
            --region "$REGION" || log "Failed to delete namespace"
    fi
    
    log "Cleanup completed."
}

# Set up trap for cleanup on script exit
trap cleanup EXIT INT TERM

# Initialize log file
> "$LOG_FILE"
log "Starting AWS Cloud Map tutorial script"

# Step 1: Create an AWS Cloud Map namespace
log "Creating AWS Cloud Map namespace: $NAMESPACE_NAME"
OPERATION_RESULT=$(aws servicediscovery create-public-dns-namespace \
    --name "$NAMESPACE_NAME" \
    --creator-request-id "cloudmap-tutorial-$CREATOR_REQUEST_ID" \
    --region "$REGION")

OPERATION_ID=$(echo "$OPERATION_RESULT" | jq -r '.OperationId')
log "Namespace creation initiated. Operation ID: $OPERATION_ID"

# Check operation status
check_operation "$OPERATION_ID"

# Get the namespace ID
log "Getting namespace ID..."
NAMESPACE_ID=$(aws servicediscovery list-namespaces \
    --region "$REGION" \
    --query "Namespaces[?Name=='$NAMESPACE_NAME'].Id" \
    --output text)

log "Namespace ID: $NAMESPACE_ID"

# Get the hosted zone ID
log "Getting Route 53 hosted zone ID..."
HOSTED_ZONE_ID=$(aws route53 list-hosted-zones-by-name \
    --dns-name "$NAMESPACE_NAME" \
    --query "HostedZones[0].Id" \
    --output text | sed 's|/hostedzone/||')

log "Hosted Zone ID: $HOSTED_ZONE_ID"

# Step 2: Create the AWS Cloud Map services
log "Creating public service..."
PUBLIC_SERVICE_RESULT=$(aws servicediscovery create-service \
    --name "public-service" \
    --namespace-id "$NAMESPACE_ID" \
    --dns-config "RoutingPolicy=MULTIVALUE,DnsRecords=[{Type=A,TTL=300}]" \
    --region "$REGION")

PUBLIC_SERVICE_ID=$(echo "$PUBLIC_SERVICE_RESULT" | jq -r '.Service.Id')
log "Public service created. Service ID: $PUBLIC_SERVICE_ID"

log "Creating backend service..."
BACKEND_SERVICE_RESULT=$(aws servicediscovery create-service \
    --name "backend-service" \
    --namespace-id "$NAMESPACE_ID" \
    --type "HTTP" \
    --region "$REGION")

BACKEND_SERVICE_ID=$(echo "$BACKEND_SERVICE_RESULT" | jq -r '.Service.Id')
log "Backend service created. Service ID: $BACKEND_SERVICE_ID"

# Step 3: Register the AWS Cloud Map service instances
log "Registering first service instance..."
FIRST_INSTANCE_RESULT=$(aws servicediscovery register-instance \
    --service-id "$PUBLIC_SERVICE_ID" \
    --instance-id "first" \
    --attributes "AWS_INSTANCE_IPV4=192.168.2.1" \
    --region "$REGION")

FIRST_INSTANCE_ID="first"
FIRST_OPERATION_ID=$(echo "$FIRST_INSTANCE_RESULT" | jq -r '.OperationId')
log "First instance registration initiated. Operation ID: $FIRST_OPERATION_ID"

# Check operation status
check_operation "$FIRST_OPERATION_ID"

log "Registering second service instance..."
SECOND_INSTANCE_RESULT=$(aws servicediscovery register-instance \
    --service-id "$BACKEND_SERVICE_ID" \
    --instance-id "second" \
    --attributes "service-name=backend" \
    --region "$REGION")

SECOND_INSTANCE_ID="second"
SECOND_OPERATION_ID=$(echo "$SECOND_INSTANCE_RESULT" | jq -r '.OperationId')
log "Second instance registration initiated. Operation ID: $SECOND_OPERATION_ID"

# Check operation status
check_operation "$SECOND_OPERATION_ID"

# Step 4: Discover the AWS Cloud Map service instances
log "Getting Route 53 name servers..."
NAME_SERVERS=$(aws route53 get-hosted-zone \
    --id "$HOSTED_ZONE_ID" \
    --query "DelegationSet.NameServers[0]" \
    --output text)

log "Name server: $NAME_SERVERS"

log "Using dig to query DNS records (this will be simulated)..."
log "Command: dig @$NAME_SERVERS public-service.$NAMESPACE_NAME"
log "Expected output would show: public-service.$NAMESPACE_NAME. 300 IN A 192.168.2.1"

log "Using AWS CLI to discover backend service instances..."
DISCOVER_RESULT=$(aws servicediscovery discover-instances \
    --namespace-name "$NAMESPACE_NAME" \
    --service-name "backend-service" \
    --region "$REGION")

log "Discovery result: $(echo "$DISCOVER_RESULT" | jq -c '.')"

# Display created resources
log "Resources created:"
log "- Namespace: $NAMESPACE_NAME (ID: $NAMESPACE_ID)"
log "- Public Service: public-service (ID: $PUBLIC_SERVICE_ID)"
log "- Backend Service: backend-service (ID: $BACKEND_SERVICE_ID)"
log "- Service Instance: first (Service: public-service)"
log "- Service Instance: second (Service: backend-service)"

# Ask user if they want to clean up resources
read -p "Do you want to clean up all created resources? (y/n): " CLEANUP_RESPONSE

if [[ "$CLEANUP_RESPONSE" == "y" || "$CLEANUP_RESPONSE" == "Y" ]]; then
    log "User confirmed cleanup. Proceeding with resource deletion."
    # Cleanup function will be called automatically on exit
else
    log "User chose not to clean up resources. Exiting without cleanup."
    trap - EXIT
    exit 0
fi

• For API details, see the following topics in AWS CLI Command Reference.

  • CreatePublicDnsNamespace

  • CreateService

  • DeleteNamespace

  • DeleteService

  • DeregisterInstance

  • DiscoverInstances

  • GetOperation

  • ListNamespaces

  • RegisterInstance