Bash Script to tag AWS resources in bulk

aws_bulk_tagger.sh

#!/bin/bash

# Configuration
APP_CODE_VALUE=""
SERVICE_PHASE_VALUE=""
COST_CENTER_VALUE=""
REGION="us-east-1" # Change to your target region

TAG_SET="app-code=${APP_CODE_VALUE},service-phase=${SERVICE_PHASE_VALUE},cost-center=${COST_CENTER_VALUE}"

echo "Step 1: Gathering all resource ARNs in $REGION..."

# Fetch all ARNs using the Tagging API. 
# We use --query to get just the ARNs and output as text.
RESOURCE_ARNS=$(aws resourcegroupstaggingapi get-resources \
    --region "$REGION" \
    --query 'ResourceTagMappingList[*].ResourceARN' \
    --output text)

if [ -z "$RESOURCE_ARNS" ]; then
    echo "No resources found to tag."
    exit 0
fi

# Convert the space-separated string into an array
ARNS_ARRAY=($RESOURCE_ARNS)
TOTAL_COUNT=${#ARNS_ARRAY[@]}

echo "Found $TOTAL_COUNT resources. Starting tagging process..."

# The Tagging API allows a maximum of 20 resources per call.
# We will loop through the array in chunks of 20.
BATCH_SIZE=20

for ((i=0; i<$TOTAL_COUNT; i+=$BATCH_SIZE)); do
    # Slice the array to get the current batch
    BATCH=("${ARNS_ARRAY[@]:i:BATCH_SIZE}")
    
    echo "Tagging batch $((i/BATCH_SIZE + 1)) of $(((TOTAL_COUNT + BATCH_SIZE - 1)/BATCH_SIZE))..."
    
    aws resourcegroupstaggingapi tag-resources \
        --region "$REGION" \
        --resource-arn-list ${BATCH[@]} \
        --tags "$TAG_SET"
    
    # Optional: Brief sleep to avoid hitting API rate limits (Throttling)
    sleep 0.5
done

echo "Bulk tagging complete!"