AWS WAFV2 examples using AWS CLI with Bash script

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 AWS WAFV2.
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

The following code example shows how to:
Create a web ACL
Add a string match rule
Add managed rules
Configure logging
Clean up resources
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 WAF Getting Started Script
# This script creates a Web ACL with a string match rule and AWS Managed Rules,
# associates it with a CloudFront distribution, and then cleans up all resources.

# Set up logging
LOG_FILE="waf-tutorial.log"
exec > >(tee -a "$LOG_FILE") 2>&1

echo "==================================================="
echo "AWS WAF Getting Started Tutorial"
echo "==================================================="
echo "This script will create AWS WAF resources and associate"
echo "them with a CloudFront distribution."
echo ""

# Maximum number of retries for operations
MAX_RETRIES=3

# Function to handle errors
handle_error() {
    echo "ERROR: $1"
    echo "Check the log file for details: $LOG_FILE"
    cleanup_resources
    exit 1
}

# Function to check command success
check_command() {
    if echo "$1" | grep -i "error" > /dev/null; then
        handle_error "$2: $1"
    fi
}

# Function to clean up resources
cleanup_resources() {
    echo ""
    echo "==================================================="
    echo "CLEANING UP RESOURCES"
    echo "==================================================="
    
    if [ -n "$DISTRIBUTION_ID" ] && [ -n "$WEB_ACL_ARN" ]; then
        echo "Disassociating Web ACL from CloudFront distribution..."
        DISASSOCIATE_RESULT=$(aws wafv2 disassociate-web-acl \
            --resource-arn "arn:aws:cloudfront::$(aws sts get-caller-identity --query Account --output text):distribution/$DISTRIBUTION_ID" \
            --region us-east-1 2>&1)
        
        if echo "$DISASSOCIATE_RESULT" | grep -i "error" > /dev/null; then
            echo "Warning: Failed to disassociate Web ACL: $DISASSOCIATE_RESULT"
        else
            echo "Web ACL disassociated successfully."
        fi
    fi
    
    if [ -n "$WEB_ACL_ID" ] && [ -n "$WEB_ACL_NAME" ]; then
        echo "Deleting Web ACL..."
        
        # Get the latest lock token before deletion
        GET_RESULT=$(aws wafv2 get-web-acl \
            --name "$WEB_ACL_NAME" \
            --scope CLOUDFRONT \
            --id "$WEB_ACL_ID" \
            --region us-east-1 2>&1)
        
        if echo "$GET_RESULT" | grep -i "error" > /dev/null; then
            echo "Warning: Failed to get Web ACL for deletion: $GET_RESULT"
            echo "You may need to manually delete the Web ACL using the AWS Console."
        else
            LATEST_TOKEN=$(echo "$GET_RESULT" | grep -o '"LockToken": "[^"]*' | cut -d'"' -f4)
            
            if [ -n "$LATEST_TOKEN" ]; then
                DELETE_RESULT=$(aws wafv2 delete-web-acl \
                    --name "$WEB_ACL_NAME" \
                    --scope CLOUDFRONT \
                    --id "$WEB_ACL_ID" \
                    --lock-token "$LATEST_TOKEN" \
                    --region us-east-1 2>&1)
                
                if echo "$DELETE_RESULT" | grep -i "error" > /dev/null; then
                    echo "Warning: Failed to delete Web ACL: $DELETE_RESULT"
                    echo "You may need to manually delete the Web ACL using the AWS Console."
                else
                    echo "Web ACL deleted successfully."
                fi
            else
                echo "Warning: Could not extract lock token for deletion. You may need to manually delete the Web ACL."
            fi
        fi
    fi
    
    echo "Cleanup process completed."
}

# Generate a random identifier for resource names
RANDOM_ID=$(openssl rand -hex 4)
WEB_ACL_NAME="MyWebACL-${RANDOM_ID}"
METRIC_NAME="MyWebACLMetrics-${RANDOM_ID}"

echo "Using Web ACL name: $WEB_ACL_NAME"

# Step 1: Create a Web ACL
echo ""
echo "==================================================="
echo "STEP 1: Creating Web ACL"
echo "==================================================="

CREATE_RESULT=$(aws wafv2 create-web-acl \
    --name "$WEB_ACL_NAME" \
    --scope "CLOUDFRONT" \
    --default-action Allow={} \
    --visibility-config "SampledRequestsEnabled=true,CloudWatchMetricsEnabled=true,MetricName=$METRIC_NAME" \
    --region us-east-1 2>&1)

check_command "$CREATE_RESULT" "Failed to create Web ACL"

# Extract Web ACL ID, ARN, and Lock Token from the Summary object
WEB_ACL_ID=$(echo "$CREATE_RESULT" | grep -o '"Id": "[^"]*' | cut -d'"' -f4)
WEB_ACL_ARN=$(echo "$CREATE_RESULT" | grep -o '"ARN": "[^"]*' | cut -d'"' -f4)
LOCK_TOKEN=$(echo "$CREATE_RESULT" | grep -o '"LockToken": "[^"]*' | cut -d'"' -f4)

if [ -z "$WEB_ACL_ID" ]; then
    handle_error "Failed to extract Web ACL ID"
fi

if [ -z "$LOCK_TOKEN" ]; then
    handle_error "Failed to extract Lock Token"
fi

echo "Web ACL created successfully with ID: $WEB_ACL_ID"
echo "Lock Token: $LOCK_TOKEN"

# Step 2: Add a String Match Rule
echo ""
echo "==================================================="
echo "STEP 2: Adding String Match Rule"
echo "==================================================="

# Try to update with retries
for ((i=1; i<=MAX_RETRIES; i++)); do
    echo "Attempt $i to add string match rule..."
    
    # Get the latest lock token before updating
    GET_RESULT=$(aws wafv2 get-web-acl \
        --name "$WEB_ACL_NAME" \
        --scope CLOUDFRONT \
        --id "$WEB_ACL_ID" \
        --region us-east-1 2>&1)
    
    if echo "$GET_RESULT" | grep -i "error" > /dev/null; then
        echo "Warning: Failed to get Web ACL for update: $GET_RESULT"
        if [ "$i" -eq "$MAX_RETRIES" ]; then
            handle_error "Failed to get Web ACL after $MAX_RETRIES attempts"
        fi
        sleep 2
        continue
    fi
    
    LATEST_TOKEN=$(echo "$GET_RESULT" | grep -o '"LockToken": "[^"]*' | cut -d'"' -f4)
    
    if [ -z "$LATEST_TOKEN" ]; then
        echo "Warning: Could not extract lock token for update"
        if [ "$i" -eq "$MAX_RETRIES" ]; then
            handle_error "Failed to extract lock token after $MAX_RETRIES attempts"
        fi
        sleep 2
        continue
    fi
    
    echo "Using lock token: $LATEST_TOKEN"
    
    UPDATE_RESULT=$(aws wafv2 update-web-acl \
        --name "$WEB_ACL_NAME" \
        --scope "CLOUDFRONT" \
        --id "$WEB_ACL_ID" \
        --lock-token "$LATEST_TOKEN" \
        --default-action Allow={} \
        --rules '[{
            "Name": "UserAgentRule",
            "Priority": 0,
            "Statement": {
                "ByteMatchStatement": {
                    "SearchString": "MyAgent",
                    "FieldToMatch": {
                        "SingleHeader": {
                            "Name": "user-agent"
                        }
                    },
                    "TextTransformations": [
                        {
                            "Priority": 0,
                            "Type": "NONE"
                        }
                    ],
                    "PositionalConstraint": "EXACTLY"
                }
            },
            "Action": {
                "Count": {}
            },
            "VisibilityConfig": {
                "SampledRequestsEnabled": true,
                "CloudWatchMetricsEnabled": true,
                "MetricName": "UserAgentRuleMetric"
            }
        }]' \
        --visibility-config "SampledRequestsEnabled=true,CloudWatchMetricsEnabled=true,MetricName=$METRIC_NAME" \
        --region us-east-1 2>&1)
    
    if echo "$UPDATE_RESULT" | grep -i "WAFOptimisticLockException" > /dev/null; then
        echo "Optimistic lock exception encountered. Will retry with new lock token."
        if [ "$i" -eq "$MAX_RETRIES" ]; then
            handle_error "Failed to add string match rule after $MAX_RETRIES attempts: $UPDATE_RESULT"
        fi
        sleep 2
        continue
    elif echo "$UPDATE_RESULT" | grep -i "error" > /dev/null; then
        handle_error "Failed to add string match rule: $UPDATE_RESULT"
    else
        # Success
        echo "String match rule added successfully."
        break
    fi
done

# Step 3: Add AWS Managed Rules
echo ""
echo "==================================================="
echo "STEP 3: Adding AWS Managed Rules"
echo "==================================================="

# Try to update with retries
for ((i=1; i<=MAX_RETRIES; i++)); do
    echo "Attempt $i to add AWS Managed Rules..."
    
    # Get the latest lock token before updating
    GET_RESULT=$(aws wafv2 get-web-acl \
        --name "$WEB_ACL_NAME" \
        --scope CLOUDFRONT \
        --id "$WEB_ACL_ID" \
        --region us-east-1 2>&1)
    
    if echo "$GET_RESULT" | grep -i "error" > /dev/null; then
        echo "Warning: Failed to get Web ACL for update: $GET_RESULT"
        if [ "$i" -eq "$MAX_RETRIES" ]; then
            handle_error "Failed to get Web ACL after $MAX_RETRIES attempts"
        fi
        sleep 2
        continue
    fi
    
    LATEST_TOKEN=$(echo "$GET_RESULT" | grep -o '"LockToken": "[^"]*' | cut -d'"' -f4)
    
    if [ -z "$LATEST_TOKEN" ]; then
        echo "Warning: Could not extract lock token for update"
        if [ "$i" -eq "$MAX_RETRIES" ]; then
            handle_error "Failed to extract lock token after $MAX_RETRIES attempts"
        fi
        sleep 2
        continue
    fi
    
    echo "Using lock token: $LATEST_TOKEN"
    
    UPDATE_RESULT=$(aws wafv2 update-web-acl \
        --name "$WEB_ACL_NAME" \
        --scope "CLOUDFRONT" \
        --id "$WEB_ACL_ID" \
        --lock-token "$LATEST_TOKEN" \
        --default-action Allow={} \
        --rules '[{
            "Name": "UserAgentRule",
            "Priority": 0,
            "Statement": {
                "ByteMatchStatement": {
                    "SearchString": "MyAgent",
                    "FieldToMatch": {
                        "SingleHeader": {
                            "Name": "user-agent"
                        }
                    },
                    "TextTransformations": [
                        {
                            "Priority": 0,
                            "Type": "NONE"
                        }
                    ],
                    "PositionalConstraint": "EXACTLY"
                }
            },
            "Action": {
                "Count": {}
            },
            "VisibilityConfig": {
                "SampledRequestsEnabled": true,
                "CloudWatchMetricsEnabled": true,
                "MetricName": "UserAgentRuleMetric"
            }
        },
        {
            "Name": "AWS-AWSManagedRulesCommonRuleSet",
            "Priority": 1,
            "Statement": {
                "ManagedRuleGroupStatement": {
                    "VendorName": "AWS",
                    "Name": "AWSManagedRulesCommonRuleSet",
                    "ExcludedRules": []
                }
            },
            "OverrideAction": {
                "Count": {}
            },
            "VisibilityConfig": {
                "SampledRequestsEnabled": true,
                "CloudWatchMetricsEnabled": true,
                "MetricName": "AWS-AWSManagedRulesCommonRuleSet"
            }
        }]' \
        --visibility-config "SampledRequestsEnabled=true,CloudWatchMetricsEnabled=true,MetricName=$METRIC_NAME" \
        --region us-east-1 2>&1)
    
    if echo "$UPDATE_RESULT" | grep -i "WAFOptimisticLockException" > /dev/null; then
        echo "Optimistic lock exception encountered. Will retry with new lock token."
        if [ "$i" -eq "$MAX_RETRIES" ]; then
            handle_error "Failed to add AWS Managed Rules after $MAX_RETRIES attempts: $UPDATE_RESULT"
        fi
        sleep 2
        continue
    elif echo "$UPDATE_RESULT" | grep -i "error" > /dev/null; then
        handle_error "Failed to add AWS Managed Rules: $UPDATE_RESULT"
    else
        # Success
        echo "AWS Managed Rules added successfully."
        break
    fi
done

# Step 4: List CloudFront distributions
echo ""
echo "==================================================="
echo "STEP 4: Listing CloudFront Distributions"
echo "==================================================="

CF_RESULT=$(aws cloudfront list-distributions --query "DistributionList.Items[*].{Id:Id,DomainName:DomainName}" --output table 2>&1)
if echo "$CF_RESULT" | grep -i "error" > /dev/null; then
    echo "Warning: Failed to list CloudFront distributions: $CF_RESULT"
    echo "Continuing without CloudFront association."
else
    echo "$CF_RESULT"

    # Ask user to select a CloudFront distribution
    echo ""
    echo "==================================================="
    echo "STEP 5: Associate Web ACL with CloudFront Distribution"
    echo "==================================================="
    echo "Enter the ID of the CloudFront distribution to associate with the Web ACL:"
    echo "(If you don't have a CloudFront distribution, press Enter to skip this step)"
    read -r DISTRIBUTION_ID

    if [ -n "$DISTRIBUTION_ID" ]; then
        ASSOCIATE_RESULT=$(aws wafv2 associate-web-acl \
            --web-acl-arn "$WEB_ACL_ARN" \
            --resource-arn "arn:aws:cloudfront::$(aws sts get-caller-identity --query Account --output text):distribution/$DISTRIBUTION_ID" \
            --region us-east-1 2>&1)
        
        if echo "$ASSOCIATE_RESULT" | grep -i "error" > /dev/null; then
            echo "Warning: Failed to associate Web ACL with CloudFront distribution: $ASSOCIATE_RESULT"
            echo "Continuing without CloudFront association."
            DISTRIBUTION_ID=""
        else
            echo "Web ACL associated with CloudFront distribution successfully."
        fi
    else
        echo "Skipping association with CloudFront distribution."
    fi
fi

# Display summary of created resources
echo ""
echo "==================================================="
echo "RESOURCE SUMMARY"
echo "==================================================="
echo "Web ACL Name: $WEB_ACL_NAME"
echo "Web ACL ID: $WEB_ACL_ID"
echo "Web ACL ARN: $WEB_ACL_ARN"
if [ -n "$DISTRIBUTION_ID" ]; then
    echo "Associated CloudFront Distribution: $DISTRIBUTION_ID"
fi
echo ""

# Ask user if they want to clean up resources
echo "==================================================="
echo "CLEANUP CONFIRMATION"
echo "==================================================="
echo "Do you want to clean up all created resources? (y/n): "
read -r CLEANUP_CHOICE

if [[ "$CLEANUP_CHOICE" =~ ^[Yy] ]]; then
    cleanup_resources
else
    echo ""
    echo "Resources have NOT been cleaned up. You can manually clean them up later."
    echo "To clean up resources manually, run the following commands:"
    if [ -n "$DISTRIBUTION_ID" ]; then
        echo "aws wafv2 disassociate-web-acl --resource-arn \"arn:aws:cloudfront::$(aws sts get-caller-identity --query Account --output text):distribution/$DISTRIBUTION_ID\" --region us-east-1"
    fi
    echo "aws wafv2 delete-web-acl --name \"$WEB_ACL_NAME\" --scope CLOUDFRONT --id \"$WEB_ACL_ID\" --lock-token \"<get-latest-token>\" --region us-east-1"
    echo ""
    echo "To get the latest lock token, run:"
    echo "aws wafv2 get-web-acl --name \"$WEB_ACL_NAME\" --scope CLOUDFRONT --id \"$WEB_ACL_ID\" --region us-east-1"
fi

echo ""
echo "==================================================="
echo "Tutorial completed!"
echo "==================================================="
echo "Log file: $LOG_FILE"
For API details, see the following topics in AWS CLI Command Reference.
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