There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# CloudWatch Logs examples using AWS CLI with Bash script
<a name="bash_2_cloudwatch-logs_code_examples"></a>

The following code examples show you how to perform actions and implement common scenarios by using the AWS Command Line Interface with Bash script with CloudWatch Logs.

*Scenarios* are code examples that show you how to accomplish specific tasks by calling multiple functions within a service or combined with other AWS services.

Each example includes a link to the complete source code, where you can find instructions on how to set up and run the code in context.

**Topics**
+ [Scenarios](#scenarios)

## Scenarios
<a name="scenarios"></a>

### Configure Amazon ECS Service Connect
<a name="ecs_ServiceConnect_085_bash_2_topic"></a>

The following code example shows how to:
+ Create the VPC infrastructure
+ Set up logging
+ Create the ECS cluster
+ Configure IAM roles
+ Create the service with Service Connect
+ Verify the deployment
+ Clean up resources

**AWS CLI with Bash script**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Sample developer tutorials](https://github.com/aws-samples/sample-developer-tutorials/tree/main/tuts/085-amazon-ecs-service-connect) repository. 

```
#!/bin/bash

# ECS Service Connect Tutorial Script v4 - Modified to use Default VPC
# This script creates an ECS cluster with Service Connect and deploys an nginx service
# Uses the default VPC to avoid VPC limits

set -e  # Exit on any error

# Configuration
SCRIPT_NAME="ECS Service Connect Tutorial"
LOG_FILE="ecs-service-connect-tutorial-v4-default-vpc.log"
REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null)}}
if [ -z "$REGION" ]; then
    echo "ERROR: No AWS region configured."
    echo "Set one with: aws configure set region us-east-1"
    exit 1
fi
ENV_PREFIX="tutorial"
CLUSTER_NAME="${ENV_PREFIX}-cluster"
NAMESPACE_NAME="service-connect"

# Generate random suffix for unique resource names
RANDOM_SUFFIX=$(openssl rand -hex 6)

# Arrays to track created resources for cleanup
declare -a CREATED_RESOURCES=()

# Logging function
log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1" | tee -a "$LOG_FILE"
}

# Error handling function
handle_error() {
    log "ERROR: Script failed at line $1"
    log "Attempting to clean up resources..."
    cleanup_resources
    exit 1
}

# Set up error handling
trap 'handle_error $LINENO' ERR

# Function to add resource to tracking array
track_resource() {
    CREATED_RESOURCES+=("$1")
    log "Tracking resource: $1"
}

# Function to check if command output contains actual errors
check_for_errors() {
    local output="$1"
    local command_name="$2"
    
    # Check for specific AWS CLI error patterns, not just any occurrence of "error"
    if echo "$output" | grep -qi "An error occurred\|InvalidParameterException\|AccessDenied\|ValidationException\|ResourceNotFoundException"; then
        log "ERROR in $command_name: $output"
        return 1
    fi
    return 0
}

# Function to get AWS account ID
get_account_id() {
    ACCOUNT_ID=$(aws sts get-caller-identity --query Account --output text)
    log "Using AWS Account ID: $ACCOUNT_ID"
}

# Function to wait for resources to be ready
wait_for_resource() {
    local resource_type="$1"
    local resource_id="$2"
    
    case "$resource_type" in
        "cluster")
            log "Waiting for cluster $resource_id to be active..."
            local attempt=1
            local max_attempts=30
            while [ $attempt -le $max_attempts ]; do
                local status=$(aws ecs describe-clusters --clusters "$resource_id" --query 'clusters[0].status' --output text)
                if [ "$status" = "ACTIVE" ]; then
                    log "Cluster is now active"
                    return 0
                fi
                log "Cluster status: $status (attempt $attempt/$max_attempts)"
                sleep 10
                ((attempt++))
            done
            log "ERROR: Cluster did not become active within expected time"
            return 1
            ;;
        "service")
            log "Waiting for service $resource_id to be stable..."
            aws ecs wait services-stable --cluster "$CLUSTER_NAME" --services "$resource_id"
            ;;
        "nat-gateway")
            log "Waiting for NAT Gateway $resource_id to be available..."
            aws ec2 wait nat-gateway-available --nat-gateway-ids "$resource_id"
            ;;
    esac
}

# Function to use default VPC infrastructure
setup_default_vpc_infrastructure() {
    log "Using default VPC infrastructure..."
    
    # Get default VPC
    VPC_ID=$(aws ec2 describe-vpcs --filters "Name=isDefault,Values=true" --query 'Vpcs[0].VpcId' --output text)
    if [[ "$VPC_ID" == "None" || -z "$VPC_ID" ]]; then
        log "ERROR: No default VPC found. Please create a default VPC first."
        exit 1
    fi
    log "Using default VPC: $VPC_ID"
    
    # Get default subnets
    SUBNETS=$(aws ec2 describe-subnets --filters "Name=vpc-id,Values=$VPC_ID" "Name=default-for-az,Values=true" --query 'Subnets[].SubnetId' --output text)
    SUBNET_ARRAY=($SUBNETS)
    
    if [ ${#SUBNET_ARRAY[@]} -lt 2 ]; then
        log "ERROR: Need at least 2 subnets for ECS Service Connect. Found: ${#SUBNET_ARRAY[@]}"
        exit 1
    fi
    
    PUBLIC_SUBNET1=${SUBNET_ARRAY[0]}
    PUBLIC_SUBNET2=${SUBNET_ARRAY[1]}
    
    log "Using subnets: $PUBLIC_SUBNET1, $PUBLIC_SUBNET2"
    
    # Create security group for ECS tasks
    SG_OUTPUT=$(aws ec2 create-security-group \
        --group-name "${ENV_PREFIX}-ecs-sg-${RANDOM_SUFFIX}" \
        --description "Security group for ECS Service Connect tutorial" \
        --vpc-id "$VPC_ID" 2>&1)
    check_for_errors "$SG_OUTPUT" "create-security-group"
    SECURITY_GROUP_ID=$(echo "$SG_OUTPUT" | grep -o '"GroupId": "[^"]*"' | cut -d'"' -f4)
    track_resource "SG:$SECURITY_GROUP_ID"
    log "Created security group: $SECURITY_GROUP_ID"
    
    # Add inbound rules to security group
    aws ec2 authorize-security-group-ingress \
        --group-id "$SECURITY_GROUP_ID" \
        --protocol tcp \
        --port 80 \
        --cidr 0.0.0.0/0 >/dev/null 2>&1 || true
    
    aws ec2 authorize-security-group-ingress \
        --group-id "$SECURITY_GROUP_ID" \
        --protocol tcp \
        --port 443 \
        --cidr 0.0.0.0/0 >/dev/null 2>&1 || true
    
    log "Default VPC infrastructure setup completed"
}

# Function to create CloudWatch log groups
create_log_groups() {
    log "Creating CloudWatch log groups..."
    
    # Create log group for nginx container
    aws logs create-log-group --log-group-name "/ecs/service-connect-nginx" 2>&1 | grep -v "ResourceAlreadyExistsException" || {
        if [ ${PIPESTATUS[0]} -eq 0 ]; then
            log "Log group /ecs/service-connect-nginx created"
            track_resource "LOG_GROUP:/ecs/service-connect-nginx"
        else
            log "Log group /ecs/service-connect-nginx already exists"
        fi
    }
    
    # Create log group for service connect proxy
    aws logs create-log-group --log-group-name "/ecs/service-connect-proxy" 2>&1 | grep -v "ResourceAlreadyExistsException" || {
        if [ ${PIPESTATUS[0]} -eq 0 ]; then
            log "Log group /ecs/service-connect-proxy created"
            track_resource "LOG_GROUP:/ecs/service-connect-proxy"
        else
            log "Log group /ecs/service-connect-proxy already exists"
        fi
    }
}

# Function to create ECS cluster with Service Connect
create_ecs_cluster() {
    log "Creating ECS cluster with Service Connect..."
    
    CLUSTER_OUTPUT=$(aws ecs create-cluster \
        --cluster-name "$CLUSTER_NAME" \
        --service-connect-defaults namespace="$NAMESPACE_NAME" \
        --tags key=Environment,value=tutorial 2>&1)
    check_for_errors "$CLUSTER_OUTPUT" "create-cluster"
    
    track_resource "CLUSTER:$CLUSTER_NAME"
    log "Created ECS cluster: $CLUSTER_NAME"
    
    wait_for_resource "cluster" "$CLUSTER_NAME"
    
    # Track the Service Connect namespace that gets created
    # Wait a moment for the namespace to be created
    sleep 5
    NAMESPACE_ID=$(aws servicediscovery list-namespaces \
        --filters Name=TYPE,Values=HTTP \
        --query "Namespaces[?Name=='$NAMESPACE_NAME'].Id" --output text 2>/dev/null || echo "")
    
    if [[ -n "$NAMESPACE_ID" && "$NAMESPACE_ID" != "None" ]]; then
        track_resource "NAMESPACE:$NAMESPACE_ID"
        log "Service Connect namespace created: $NAMESPACE_ID"
    fi
}

# Function to create IAM roles
create_iam_roles() {
    log "Creating IAM roles..."
    
    # Check if ecsTaskExecutionRole exists
    if aws iam get-role --role-name ecsTaskExecutionRole >/dev/null 2>&1; then
        log "IAM role ecsTaskExecutionRole exists"
    else
        log "Creating ecsTaskExecutionRole..."
        aws iam create-role \
            --role-name ecsTaskExecutionRole \
            --assume-role-policy-document '{
                "Version":"2012-10-17",		 	 	 
                "Statement": [{
                    "Effect": "Allow",
                    "Principal": {"Service": "ecs-tasks.amazonaws.com"},
                    "Action": "sts:AssumeRole"
                }]
            }' >/dev/null 2>&1
        aws iam attach-role-policy \
            --role-name ecsTaskExecutionRole \
            --policy-arn arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy >/dev/null 2>&1
        track_resource "ROLE:ecsTaskExecutionRole"
        log "Created ecsTaskExecutionRole"
        sleep 10
    fi
    
    # Check if ecsTaskRole exists, create if not
    if aws iam get-role --role-name ecsTaskRole >/dev/null 2>&1; then
        log "IAM role ecsTaskRole exists"
    else
        log "IAM role ecsTaskRole does not exist, will create it"
        
        # Create trust policy for ECS tasks
        cat > /tmp/ecs-task-trust-policy.json << EOF
{
    "Version":"2012-10-17",		 	 	 
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service": "ecs-tasks.amazonaws.com"
            },
            "Action": "sts:AssumeRole"
        }
    ]
}
EOF
        
        aws iam create-role \
            --role-name ecsTaskRole \
            --assume-role-policy-document file:///tmp/ecs-task-trust-policy.json >/dev/null
        
        track_resource "IAM_ROLE:ecsTaskRole"
        log "Created ecsTaskRole"
        
        # Wait for role to be available
        sleep 10
    fi
}

# Function to create task definition
create_task_definition() {
    log "Creating task definition..."
    
    # Create task definition JSON
    cat > /tmp/task-definition.json << EOF
{
    "family": "service-connect-nginx",
    "networkMode": "awsvpc",
    "requiresCompatibilities": ["FARGATE"],
    "cpu": "256",
    "memory": "512",
    "executionRoleArn": "arn:aws:iam::${ACCOUNT_ID}:role/ecsTaskExecutionRole",
    "taskRoleArn": "arn:aws:iam::${ACCOUNT_ID}:role/ecsTaskRole",
    "containerDefinitions": [
        {
            "name": "nginx",
            "image": "public.ecr.aws/docker/library/nginx:latest",
            "portMappings": [
                {
                    "containerPort": 80,
                    "protocol": "tcp",
                    "name": "nginx-port"
                }
            ],
            "essential": true,
            "logConfiguration": {
                "logDriver": "awslogs",
                "options": {
                    "awslogs-group": "/ecs/service-connect-nginx",
                    "awslogs-region": "${REGION}",
                    "awslogs-stream-prefix": "ecs"
                }
            }
        }
    ]
}
EOF
    
    TASK_DEF_OUTPUT=$(aws ecs register-task-definition --cli-input-json file:///tmp/task-definition.json 2>&1)
    check_for_errors "$TASK_DEF_OUTPUT" "register-task-definition"
    
    TASK_DEF_ARN=$(echo "$TASK_DEF_OUTPUT" | grep -o '"taskDefinitionArn": "[^"]*"' | cut -d'"' -f4)
    track_resource "TASK_DEF:service-connect-nginx"
    log "Created task definition: $TASK_DEF_ARN"
    
    # Clean up temporary file
    rm -f /tmp/task-definition.json
}

# Function to create ECS service with Service Connect
create_ecs_service() {
    log "Creating ECS service with Service Connect..."
    
    # Create service definition JSON
    cat > /tmp/service-definition.json << EOF
{
    "serviceName": "service-connect-nginx-service",
    "cluster": "${CLUSTER_NAME}",
    "taskDefinition": "service-connect-nginx",
    "desiredCount": 1,
    "launchType": "FARGATE",
    "networkConfiguration": {
        "awsvpcConfiguration": {
            "subnets": ["${PUBLIC_SUBNET1}", "${PUBLIC_SUBNET2}"],
            "securityGroups": ["${SECURITY_GROUP_ID}"],
            "assignPublicIp": "ENABLED"
        }
    },
    "serviceConnectConfiguration": {
        "enabled": true,
        "namespace": "${NAMESPACE_NAME}",
        "services": [
            {
                "portName": "nginx-port",
                "discoveryName": "nginx",
                "clientAliases": [
                    {
                        "port": 80,
                        "dnsName": "nginx"
                    }
                ]
            }
        ],
        "logConfiguration": {
            "logDriver": "awslogs",
            "options": {
                "awslogs-group": "/ecs/service-connect-proxy",
                "awslogs-region": "${REGION}",
                "awslogs-stream-prefix": "ecs-service-connect"
            }
        }
    },
    "tags": [
        {
            "key": "Environment",
            "value": "tutorial"
        }
    ]
}
EOF
    
    SERVICE_OUTPUT=$(aws ecs create-service --cli-input-json file:///tmp/service-definition.json 2>&1)
    check_for_errors "$SERVICE_OUTPUT" "create-service"
    
    track_resource "SERVICE:service-connect-nginx-service"
    log "Created ECS service: service-connect-nginx-service"
    
    wait_for_resource "service" "service-connect-nginx-service"
    
    # Clean up temporary file
    rm -f /tmp/service-definition.json
}

# Function to verify deployment
verify_deployment() {
    log "Verifying deployment..."
    
    # Check service status
    SERVICE_STATUS=$(aws ecs describe-services \
        --cluster "$CLUSTER_NAME" \
        --services "service-connect-nginx-service" \
        --query 'services[0].status' --output text)
    log "Service status: $SERVICE_STATUS"
    
    # Check running tasks
    RUNNING_COUNT=$(aws ecs describe-services \
        --cluster "$CLUSTER_NAME" \
        --services "service-connect-nginx-service" \
        --query 'services[0].runningCount' --output text)
    log "Running tasks: $RUNNING_COUNT"
    
    # Get task ARN
    TASK_ARN=$(aws ecs list-tasks \
        --cluster "$CLUSTER_NAME" \
        --service-name "service-connect-nginx-service" \
        --query 'taskArns[0]' --output text)
    
    if [[ "$TASK_ARN" != "None" && -n "$TASK_ARN" ]]; then
        log "Task ARN: $TASK_ARN"
        
        # Try to get task IP address
        TASK_IP=$(aws ecs describe-tasks \
            --cluster "$CLUSTER_NAME" \
            --tasks "$TASK_ARN" \
            --query 'tasks[0].attachments[0].details[?name==`privateIPv4Address`].value' \
            --output text 2>/dev/null || echo "")
        
        if [[ -n "$TASK_IP" && "$TASK_IP" != "None" ]]; then
            log "Task IP address: $TASK_IP"
        else
            log "Could not retrieve task IP address"
        fi
    fi
    
    # Check Service Connect namespace
    NAMESPACE_STATUS=$(aws servicediscovery list-namespaces \
        --filters Name=TYPE,Values=HTTP \
        --query "Namespaces[?Name=='$NAMESPACE_NAME'].Id" --output text 2>/dev/null || echo "")
    
    if [[ -n "$NAMESPACE_STATUS" && "$NAMESPACE_STATUS" != "None" ]]; then
        log "Service Connect namespace '$NAMESPACE_NAME' is active"
    else
        log "Service Connect namespace '$NAMESPACE_NAME' not found or not active"
    fi
    
    # Display Service Connect configuration
    log "Service Connect configuration:"
    aws ecs describe-services \
        --cluster "$CLUSTER_NAME" \
        --services "service-connect-nginx-service" \
        --query 'services[0].serviceConnectConfiguration' 2>/dev/null || true
}

# Function to display created resources
display_resources() {
    echo ""
    echo "==========================================="
    echo "CREATED RESOURCES"
    echo "==========================================="
    for resource in "${CREATED_RESOURCES[@]}"; do
        echo "- $resource"
    done
    echo "==========================================="
    echo ""
}

# Function to cleanup resources
cleanup_resources() {
    log "Starting cleanup process..."
    
    # Delete resources in reverse order of creation
    for ((i=${#CREATED_RESOURCES[@]}-1; i>=0; i--)); do
        resource="${CREATED_RESOURCES[i]}"
        resource_type=$(echo "$resource" | cut -d':' -f1)
        resource_id=$(echo "$resource" | cut -d':' -f2)
        
        log "Cleaning up $resource_type: $resource_id"
        
        case "$resource_type" in
            "SERVICE")
                aws ecs update-service --cluster "$CLUSTER_NAME" --service "$resource_id" --desired-count 0 2>&1 | grep -qi "error" && log "Warning: Failed to scale down service $resource_id"
                aws ecs wait services-stable --cluster "$CLUSTER_NAME" --services "$resource_id" 2>/dev/null || true
                aws ecs delete-service --cluster "$CLUSTER_NAME" --service "$resource_id" --force 2>&1 | grep -qi "error" && log "Warning: Failed to delete service $resource_id"
                ;;
            "TASK_DEF")
                TASK_DEF_ARNS=$(aws ecs list-task-definitions --family-prefix "$resource_id" --query 'taskDefinitionArns' --output text 2>/dev/null)
                for arn in $TASK_DEF_ARNS; do
                    aws ecs deregister-task-definition --task-definition "$arn" >/dev/null 2>&1 || true
                done
                ;;
            "ROLE")
                aws iam detach-role-policy --role-name "$resource_id" --policy-arn "arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy" 2>/dev/null || true
                aws iam delete-role --role-name "$resource_id" 2>&1 | grep -qi "error" && log "Warning: Failed to delete role $resource_id"
                ;;
            "IAM_ROLE")
                aws iam detach-role-policy --role-name "$resource_id" --policy-arn "arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy" 2>/dev/null || true
                aws iam delete-role --role-name "$resource_id" 2>&1 | grep -qi "error" && log "Warning: Failed to delete role $resource_id"
                ;;
            "CLUSTER")
                aws ecs delete-cluster --cluster "$resource_id" 2>&1 | grep -qi "error" && log "Warning: Failed to delete cluster $resource_id"
                ;;
            "SG")
                for attempt in 1 2 3 4 5; do
                    if aws ec2 delete-security-group --group-id "$resource_id" 2>/dev/null; then
                        break
                    fi
                    log "Security group $resource_id still has dependencies, retrying in 30s ($attempt/5)..."
                    sleep 30
                done
                ;;
            "LOG_GROUP")
                aws logs delete-log-group --log-group-name "$resource_id" 2>&1 | grep -qi "error" && log "Warning: Failed to delete log group $resource_id"
                ;;
            "NAMESPACE")
                # First, delete any services in the namespace
                NAMESPACE_SERVICES=$(aws servicediscovery list-services \
                    --filters Name=NAMESPACE_ID,Values="$resource_id" \
                    --query 'Services[].Id' --output text 2>/dev/null || echo "")
                
                if [[ -n "$NAMESPACE_SERVICES" && "$NAMESPACE_SERVICES" != "None" ]]; then
                    for service_id in $NAMESPACE_SERVICES; do
                        aws servicediscovery delete-service --id "$service_id" >/dev/null 2>&1 || true
                        sleep 2
                    done
                fi
                
                # Then delete the namespace
                aws servicediscovery delete-namespace --id "$resource_id" >/dev/null 2>&1 || true
                ;;
        esac
        
        sleep 2  # Brief pause between deletions
    done
    
    # Clean up temporary files
    rm -f /tmp/ecs-task-trust-policy.json
    rm -f /tmp/task-definition.json
    rm -f /tmp/service-definition.json
    
    log "Cleanup completed"
}

# Main execution
main() {
    log "Starting $SCRIPT_NAME v4 (Default VPC)"
    log "Region: $REGION"
    log "Log file: $LOG_FILE"
    
    # Get AWS account ID
    get_account_id
    
    # Setup infrastructure using default VPC
    setup_default_vpc_infrastructure
    
    # Create CloudWatch log groups
    create_log_groups
    
    # Create ECS cluster
    create_ecs_cluster
    
    # Create IAM roles
    create_iam_roles
    
    # Create task definition
    create_task_definition
    
    # Create ECS service
    create_ecs_service
    
    # Verify deployment
    verify_deployment
    
    log "Tutorial completed successfully!"
    
    # Display created resources
    display_resources
    
    # Ask user if they want to clean up
    echo ""
    echo "==========================================="
    echo "CLEANUP CONFIRMATION"
    echo "==========================================="
    echo "Do you want to clean up all created resources? (y/n): "
    read -r CLEANUP_CHOICE
    
    if [[ "$CLEANUP_CHOICE" =~ ^[Yy]$ ]]; then
        cleanup_resources
        log "All resources have been cleaned up"
    else
        log "Resources left intact. You can clean them up later by running the cleanup function."
        echo ""
        echo "To clean up resources later, you can use the AWS CLI commands or the AWS Management Console."
        echo "Remember to delete resources in the correct order to avoid dependency issues."
    fi
}

# Make script executable and run
chmod +x "$0"
main "$@"
```
+ For API details, see the following topics in *AWS CLI Command Reference*.
  + [AttachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/AttachRolePolicy)
  + [AuthorizeSecurityGroupIngress](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/AuthorizeSecurityGroupIngress)
  + [CreateCluster](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/CreateCluster)
  + [CreateLogGroup](https://docs.aws.amazon.com/goto/aws-cli/logs-2014-03-28/CreateLogGroup)
  + [CreateRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/CreateRole)
  + [CreateSecurityGroup](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/CreateSecurityGroup)
  + [CreateService](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/CreateService)
  + [DeleteCluster](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/DeleteCluster)
  + [DeleteLogGroup](https://docs.aws.amazon.com/goto/aws-cli/logs-2014-03-28/DeleteLogGroup)
  + [DeleteNamespace](https://docs.aws.amazon.com/goto/aws-cli/servicediscovery-2017-03-14/DeleteNamespace)
  + [DeleteRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DeleteRole)
  + [DeleteSecurityGroup](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/DeleteSecurityGroup)
  + [DeleteService](https://docs.aws.amazon.com/goto/aws-cli/servicediscovery-2017-03-14/DeleteService)
  + [DeregisterTaskDefinition](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/DeregisterTaskDefinition)
  + [DescribeClusters](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/DescribeClusters)
  + [DescribeServices](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/DescribeServices)
  + [DescribeSubnets](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/DescribeSubnets)
  + [DescribeTasks](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/DescribeTasks)
  + [DescribeVpcs](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/DescribeVpcs)
  + [DetachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DetachRolePolicy)
  + [GetCallerIdentity](https://docs.aws.amazon.com/goto/aws-cli/sts-2011-06-15/GetCallerIdentity)
  + [GetRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/GetRole)
  + [ListNamespaces](https://docs.aws.amazon.com/goto/aws-cli/servicediscovery-2017-03-14/ListNamespaces)
  + [ListServices](https://docs.aws.amazon.com/goto/aws-cli/servicediscovery-2017-03-14/ListServices)
  + [ListTaskDefinitions](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/ListTaskDefinitions)
  + [ListTasks](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/ListTasks)
  + [RegisterTaskDefinition](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/RegisterTaskDefinition)
  + [UpdateService](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/UpdateService)
  + [Wait](https://docs.aws.amazon.com/goto/aws-cli/ecs-2014-11-13/Wait)

### Creating your first Lambda function
<a name="lambda_GettingStarted_019_bash_2_topic"></a>

The following code example shows how to:
+ Create an IAM role for Lambda
+ Create function code
+ Create a Lambda function
+ Test your Lambda function
+ Clean up resources

**AWS CLI with Bash script**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Sample developer tutorials](https://github.com/aws-samples/sample-developer-tutorials/tree/main/tuts/019-lambda-gettingstarted) repository. 

```
#!/bin/bash
# AWS Lambda - Create Your First Function
# This script creates a Lambda function, invokes it with a test event,
# views CloudWatch logs, and cleans up all resources.
#
# Source: https://docs.aws.amazon.com/lambda/latest/dg/getting-started.html
#
# Resources created:
#   - IAM role (Lambda execution role with basic logging permissions)
#   - Lambda function (Python 3.13 or Node.js 22.x runtime)
#   - CloudWatch log group (created automatically by Lambda on invocation)

set -eE

###############################################################################
# Setup
###############################################################################

UNIQUE_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1)
FUNCTION_NAME="my-lambda-function-${UNIQUE_ID}"
ROLE_NAME="lambda-execution-role-${UNIQUE_ID}"
LOG_GROUP_NAME="/aws/lambda/${FUNCTION_NAME}"

TEMP_DIR=$(mktemp -d)
LOG_FILE="${TEMP_DIR}/lambda-gettingstarted.log"

exec > >(tee -a "$LOG_FILE") 2>&1

declare -a CREATED_RESOURCES

###############################################################################
# Helper functions
###############################################################################

cleanup_resources() {
    # Disable error trap to prevent recursion during cleanup
    trap - ERR
    set +eE

    echo ""
    echo "Cleaning up resources..."
    echo ""

    for ((i=${#CREATED_RESOURCES[@]}-1; i>=0; i--)); do
        local RESOURCE="${CREATED_RESOURCES[$i]}"
        local TYPE="${RESOURCE%%:*}"
        local NAME="${RESOURCE#*:}"

        case "$TYPE" in
            log-group)
                echo "Deleting CloudWatch log group: ${NAME}"
                aws logs delete-log-group \
                    --log-group-name "$NAME" 2>&1 || echo "  WARNING: Could not delete log group ${NAME}."
                ;;
            lambda-function)
                echo "Deleting Lambda function: ${NAME}"
                aws lambda delete-function \
                    --function-name "$NAME" 2>&1 || echo "  WARNING: Could not delete Lambda function ${NAME}."
                echo "  Waiting for function deletion to complete..."
                local DELETE_WAIT=0
                while aws lambda get-function --function-name "$NAME" > /dev/null 2>&1; do
                    sleep 2
                    DELETE_WAIT=$((DELETE_WAIT + 2))
                    if [ "$DELETE_WAIT" -ge 60 ]; then
                        echo "  WARNING: Timed out waiting for function deletion."
                        break
                    fi
                done
                ;;
            iam-role-policy)
                local ROLE_PART="${NAME%%|*}"
                local POLICY_PART="${NAME#*|}"
                echo "Detaching policy from role: ${ROLE_PART}"
                aws iam detach-role-policy \
                    --role-name "$ROLE_PART" \
                    --policy-arn "$POLICY_PART" 2>&1 || echo "  WARNING: Could not detach policy from role ${ROLE_PART}."
                ;;
            iam-role)
                echo "Deleting IAM role: ${NAME}"
                aws iam delete-role \
                    --role-name "$NAME" 2>&1 || echo "  WARNING: Could not delete IAM role ${NAME}."
                ;;
        esac
    done

    if [ -d "$TEMP_DIR" ]; then
        rm -rf "$TEMP_DIR"
    fi

    echo ""
    echo "Cleanup complete."
}

handle_error() {
    echo ""
    echo "==========================================="
    echo "ERROR: Script failed at $1"
    echo "==========================================="
    echo ""
    if [ ${#CREATED_RESOURCES[@]} -gt 0 ]; then
        echo "Attempting to clean up ${#CREATED_RESOURCES[@]} resource(s)..."
        cleanup_resources
    fi
    exit 1
}

trap 'handle_error "line $LINENO"' ERR

wait_for_resource() {
    local DESCRIPTION="$1"
    local COMMAND="$2"
    local TARGET_VALUE="$3"
    local TIMEOUT=300
    local ELAPSED=0
    local INTERVAL=5

    echo "Waiting for ${DESCRIPTION}..."
    while true; do
        local RESULT
        RESULT=$(eval "$COMMAND" 2>&1) || true
        if echo "$RESULT" | grep -q "$TARGET_VALUE"; then
            echo "  ${DESCRIPTION} is ready."
            return 0
        fi
        if [ "$ELAPSED" -ge "$TIMEOUT" ]; then
            echo "ERROR: Timed out waiting for ${DESCRIPTION} after ${TIMEOUT} seconds."
            return 1
        fi
        sleep "$INTERVAL"
        ELAPSED=$((ELAPSED + INTERVAL))
    done
}

###############################################################################
# Region pre-check
###############################################################################

CONFIGURED_REGION=$(aws configure get region 2>/dev/null || true)
if [ -z "$CONFIGURED_REGION" ] && [ -z "$AWS_DEFAULT_REGION" ] && [ -z "$AWS_REGION" ]; then
    echo "ERROR: No AWS region configured."
    echo "Run 'aws configure set region <region>' or export AWS_DEFAULT_REGION."
    exit 1
fi

###############################################################################
# Runtime selection
###############################################################################

echo ""
echo "==========================================="
echo "AWS Lambda - Create Your First Function"
echo "==========================================="
echo ""
echo "Select a runtime for your Lambda function:"
echo "  1) Python 3.13"
echo "  2) Node.js 22.x"
echo ""
echo "Enter your choice (1 or 2): "
read -r RUNTIME_CHOICE

case "$RUNTIME_CHOICE" in
    1)
        RUNTIME="python3.13"
        HANDLER="lambda_function.lambda_handler"
        CODE_FILE="lambda_function.py"
        cat > "${TEMP_DIR}/${CODE_FILE}" << 'PYTHON_EOF'
import json
import logging
logger = logging.getLogger()
logger.setLevel(logging.INFO)
def lambda_handler(event, context):
    length = event['length']
    width = event['width']
    area = calculate_area(length, width)
    print(f'The area is {area}')
    logger.info(f'CloudWatch logs group: {context.log_group_name}')
    return json.dumps({'area': area})
def calculate_area(length, width):
    return length * width
PYTHON_EOF
        echo "Selected runtime: Python 3.13"
        ;;
    2)
        RUNTIME="nodejs22.x"
        HANDLER="index.handler"
        CODE_FILE="index.mjs"
        cat > "${TEMP_DIR}/${CODE_FILE}" << 'NODEJS_EOF'
export const handler = async (event, context) => {
  const area = event.length * event.width;
  console.log(`The area is ${area}`);
  console.log('CloudWatch log group: ', context.logGroupName);
  return JSON.stringify({area});
};
NODEJS_EOF
        echo "Selected runtime: Node.js 22.x"
        ;;
    *)
        echo "ERROR: Invalid choice. Please enter 1 or 2."
        exit 1
        ;;
esac

###############################################################################
# Step 1: Create IAM execution role
###############################################################################

echo ""
echo "==========================================="
echo "Step 1: Create IAM execution role"
echo "==========================================="
echo ""

TRUST_POLICY='{
    "Version":"2012-10-17",		 	 	 
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service": "lambda.amazonaws.com"
            },
            "Action": "sts:AssumeRole"
        }
    ]
}'

echo "Creating IAM role: ${ROLE_NAME}"
ROLE_OUTPUT=$(aws iam create-role \
    --role-name "$ROLE_NAME" \
    --assume-role-policy-document "$TRUST_POLICY" \
    --query 'Role.Arn' \
    --output text 2>&1)
echo "$ROLE_OUTPUT"
ROLE_ARN="$ROLE_OUTPUT"
CREATED_RESOURCES+=("iam-role:${ROLE_NAME}")
echo "Role ARN: ${ROLE_ARN}"

echo ""
echo "Attaching AWSLambdaBasicExecutionRole policy..."
aws iam attach-role-policy \
    --role-name "$ROLE_NAME" \
    --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole" 2>&1
CREATED_RESOURCES+=("iam-role-policy:${ROLE_NAME}|arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole")
echo "Policy attached."

# IAM roles can take a few seconds to propagate
echo "Waiting for IAM role to propagate..."
sleep 10

###############################################################################
# Step 2: Create Lambda function
###############################################################################

echo ""
echo "==========================================="
echo "Step 2: Create Lambda function"
echo "==========================================="
echo ""

echo "Creating deployment package..."
ORIGINAL_DIR=$(pwd)
cd "$TEMP_DIR"
zip -j function.zip "$CODE_FILE" > /dev/null 2>&1
cd "$ORIGINAL_DIR"

echo "Creating Lambda function: ${FUNCTION_NAME}"
echo "  Runtime: ${RUNTIME}"
echo "  Handler: ${HANDLER}"
echo ""

CREATE_OUTPUT=$(aws lambda create-function \
    --function-name "$FUNCTION_NAME" \
    --runtime "$RUNTIME" \
    --role "$ROLE_ARN" \
    --handler "$HANDLER" \
    --architectures x86_64 \
    --zip-file "fileb://${TEMP_DIR}/function.zip" \
    --query '[FunctionName, FunctionArn, Runtime, State]' \
    --output text 2>&1)
echo "$CREATE_OUTPUT"
CREATED_RESOURCES+=("lambda-function:${FUNCTION_NAME}")

wait_for_resource "Lambda function to become Active" \
    "aws lambda get-function-configuration --function-name ${FUNCTION_NAME} --query State --output text" \
    "Active"

###############################################################################
# Step 3: Invoke the function
###############################################################################

echo ""
echo "==========================================="
echo "Step 3: Invoke the function"
echo "==========================================="
echo ""

TEST_EVENT='{"length": 6, "width": 7}'
echo "Invoking function with test event: ${TEST_EVENT}"
echo ""

echo "$TEST_EVENT" > "${TEMP_DIR}/test-event.json"

INVOKE_OUTPUT=$(aws lambda invoke \
    --function-name "$FUNCTION_NAME" \
    --payload "fileb://${TEMP_DIR}/test-event.json" \
    --cli-read-timeout 30 \
    "${TEMP_DIR}/response.json" 2>&1)
echo "$INVOKE_OUTPUT"

RESPONSE=$(cat "${TEMP_DIR}/response.json")
echo ""
echo "Function response: ${RESPONSE}"
echo ""

if echo "$INVOKE_OUTPUT" | grep -qi "functionerror"; then
    echo "WARNING: Function returned an error."
fi

###############################################################################
# Step 4: View CloudWatch logs
###############################################################################

echo ""
echo "==========================================="
echo "Step 4: View CloudWatch Logs"
echo "==========================================="
echo ""

echo "Log group: ${LOG_GROUP_NAME}"
echo ""

echo "Waiting for CloudWatch logs to be available..."

LOG_STREAMS=""
for i in $(seq 1 6); do
    LOG_STREAMS=$(aws logs describe-log-streams \
        --log-group-name "$LOG_GROUP_NAME" \
        --order-by LastEventTime \
        --descending \
        --query 'logStreams[0].logStreamName' \
        --output text 2>/dev/null) || true
    if [ -n "$LOG_STREAMS" ] && [ "$LOG_STREAMS" != "None" ]; then
        break
    fi
    LOG_STREAMS=""
    sleep 5
done

if [ -n "$LOG_STREAMS" ] && [ "$LOG_STREAMS" != "None" ]; then
    echo "Latest log stream: ${LOG_STREAMS}"
    echo ""
    echo "--- Log events ---"
    LOG_EVENTS=$(aws logs get-log-events \
        --log-group-name "$LOG_GROUP_NAME" \
        --log-stream-name "$LOG_STREAMS" \
        --query 'events[].message' \
        --output text 2>&1) || true
    echo "$LOG_EVENTS"
    echo "--- End of log events ---"
else
    echo "No log streams found yet. Logs may take a moment to appear."
    echo "You can view them in the CloudWatch console:"
    echo "  Log group: ${LOG_GROUP_NAME}"
fi

CREATED_RESOURCES+=("log-group:${LOG_GROUP_NAME}")

###############################################################################
# Summary and cleanup
###############################################################################

echo ""
echo "==========================================="
echo "SUMMARY"
echo "==========================================="
echo ""
echo "Resources created:"
echo "  IAM role:          ${ROLE_NAME}"
echo "  Lambda function:   ${FUNCTION_NAME}"
echo "  CloudWatch logs:   ${LOG_GROUP_NAME}"
echo ""
echo "==========================================="
echo "CLEANUP CONFIRMATION"
echo "==========================================="
echo ""
echo "Do you want to clean up all created resources? (y/n): "
read -r CLEANUP_CHOICE

if [[ "$CLEANUP_CHOICE" =~ ^[Yy]$ ]]; then
    cleanup_resources
else
    echo ""
    echo "Resources were NOT deleted. To clean up manually, run:"
    echo ""
    echo "  # Delete the Lambda function"
    echo "  aws lambda delete-function --function-name ${FUNCTION_NAME}"
    echo ""
    echo "  # Delete the CloudWatch log group"
    echo "  aws logs delete-log-group --log-group-name ${LOG_GROUP_NAME}"
    echo ""
    echo "  # Detach the policy and delete the IAM role"
    echo "  aws iam detach-role-policy --role-name ${ROLE_NAME} --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
    echo "  aws iam delete-role --role-name ${ROLE_NAME}"
    echo ""

    if [ -d "$TEMP_DIR" ]; then
        rm -rf "$TEMP_DIR"
    fi
fi

echo ""
echo "Done."
```
+ For API details, see the following topics in *AWS CLI Command Reference*.
  + [AttachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/AttachRolePolicy)
  + [CreateFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/CreateFunction)
  + [CreateRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/CreateRole)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/DeleteFunction)
  + [DeleteLogGroup](https://docs.aws.amazon.com/goto/aws-cli/logs-2014-03-28/DeleteLogGroup)
  + [DeleteRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DeleteRole)
  + [DescribeLogStreams](https://docs.aws.amazon.com/goto/aws-cli/logs-2014-03-28/DescribeLogStreams)
  + [DetachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DetachRolePolicy)
  + [GetFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/GetFunction)
  + [GetFunctionConfiguration](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/GetFunctionConfiguration)
  + [GetLogEvents](https://docs.aws.amazon.com/goto/aws-cli/logs-2014-03-28/GetLogEvents)
  + [Invoke](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/Invoke)