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Getting started with the Glue Data Catalog - AWS SDK Code Examples

There are more AWS SDK examples available in the AWS Doc SDK Examples GitHub repo.

Getting started with the Glue Data Catalog

The following code example shows how to:

  • Create a database

  • Create a table

  • Clean up resources

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 Glue Data Catalog Tutorial Script
# This script demonstrates how to create and manage AWS Glue Data Catalog resources using the AWS CLI
# Cost improvements: Reduced API calls, optimized queries, eliminated redundant operations
# Reliability improvements: Enhanced error handling, input validation, resource tracking

set -euo pipefail

# Setup logging
LOG_FILE="glue-tutorial-$(date +%Y%m%d-%H%M%S).log"
exec > >(tee -a "$LOG_FILE") 2>&1

echo "Starting AWS Glue Data Catalog tutorial script at $(date)"
echo "All operations will be logged to $LOG_FILE"

# Generate a unique identifier for resource names
UNIQUE_ID=$(openssl rand -hex 4)
DB_NAME="tutorial-db-${UNIQUE_ID}"
TABLE_NAME="flights-data-${UNIQUE_ID}"
TABLE_INPUT_FILE="table-input-${UNIQUE_ID}.json"

# Track created resources
declare -a CREATED_RESOURCES=()

# Set default region if not provided
AWS_REGION="${AWS_REGION:-us-east-1}"

# Flag to track if database was successfully created
DATABASE_CREATED=false

# Trap to ensure cleanup on exit
trap cleanup_resources EXIT

# Function to check command status
check_status() {
    if [ $? -ne 0 ]; then
        echo "ERROR: $1 failed." >&2
        exit 1
    fi
}

# Function to cleanup resources
cleanup_resources() {
    local exit_code=$?
    echo "Attempting to clean up resources..."
    
    # Delete resources in reverse order
    for ((i=${#CREATED_RESOURCES[@]}-1; i>=0; i--)); do
        resource=${CREATED_RESOURCES[$i]}
        resource_type=$(echo "$resource" | cut -d':' -f1)
        resource_name=$(echo "$resource" | cut -d':' -f2)
        
        echo "Deleting $resource_type: $resource_name"
        
        case $resource_type in
            "table")
                if [ "$DATABASE_CREATED" = true ]; then
                    aws glue delete-table \
                        --database-name "$DB_NAME" \
                        --name "$resource_name" \
                        --region "$AWS_REGION" \
                        2>/dev/null || echo "Warning: Failed to delete table $resource_name"
                fi
                ;;
            "database")
                aws glue delete-database \
                    --name "$resource_name" \
                    --region "$AWS_REGION" \
                    2>/dev/null || echo "Warning: Failed to delete database $resource_name"
                ;;
            *)
                echo "Unknown resource type: $resource_type" >&2
                ;;
        esac
    done
    
    # Clean up temporary files securely
    if [ -f "$TABLE_INPUT_FILE" ]; then
        if command -v shred &> /dev/null; then
            shred -vfz -n 3 "$TABLE_INPUT_FILE" 2>/dev/null || rm -f "$TABLE_INPUT_FILE"
        else
            rm -f "$TABLE_INPUT_FILE"
        fi
    fi
    
    echo "Cleanup completed."
    exit $exit_code
}

# Function to validate prerequisites
validate_prerequisites() {
    # Validate AWS CLI is available
    if ! command -v aws &> /dev/null; then
        echo "ERROR: AWS CLI is not installed or not in PATH" >&2
        exit 1
    fi

    # Validate AWS CLI version
    local AWS_CLI_VERSION
    AWS_CLI_VERSION=$(aws --version 2>&1 | cut -d' ' -f1 | cut -d'/' -f2 | cut -d'.' -f1)
    if [ "$AWS_CLI_VERSION" -lt 1 ]; then
        echo "ERROR: AWS CLI is required" >&2
        exit 1
    fi

    # Validate jq is available for JSON validation
    if ! command -v jq &> /dev/null; then
        echo "ERROR: jq is not installed or not in PATH" >&2
        exit 1
    fi

    # Validate AWS credentials and get account identity in single call (cost optimization)
    local CALLER_IDENTITY
    CALLER_IDENTITY=$(aws sts get-caller-identity --region "$AWS_REGION" --query 'Account' --output text 2>/dev/null) || {
        echo "ERROR: Failed to get AWS caller identity. Check credentials and permissions." >&2
        exit 1
    }
    
    if [ -z "$CALLER_IDENTITY" ] || [ "$CALLER_IDENTITY" == "None" ]; then
        echo "ERROR: Unable to determine AWS account identity" >&2
        exit 1
    fi
    echo "Using AWS Account: $CALLER_IDENTITY"
    echo "Using Region: $AWS_REGION"
}

# Function to create database with verification
create_database() {
    echo "Step 1: Creating a database named $DB_NAME"
    
    if ! aws glue create-database \
        --database-input "Name=$DB_NAME,Description=Database for AWS Glue tutorial" \
        --region "$AWS_REGION" \
        --output json > /dev/null 2>&1; then
        echo "ERROR: Failed to create database $DB_NAME" >&2
        exit 1
    fi
    
    DATABASE_CREATED=true
    CREATED_RESOURCES+=("database:$DB_NAME")
    echo "Database $DB_NAME created successfully."
}

# Function to prepare table input JSON
prepare_table_input() {
    # Create a temporary JSON file for table input with restricted permissions
    if ! touch "$TABLE_INPUT_FILE" 2>/dev/null; then
        echo "ERROR: Failed to create temporary file $TABLE_INPUT_FILE" >&2
        exit 1
    fi
    
    if ! chmod 600 "$TABLE_INPUT_FILE" 2>/dev/null; then
        echo "ERROR: Failed to set permissions on $TABLE_INPUT_FILE" >&2
        rm -f "$TABLE_INPUT_FILE"
        exit 1
    fi

    cat > "$TABLE_INPUT_FILE" << 'EOF'
{
  "Name": "TABLE_NAME_PLACEHOLDER",
  "StorageDescriptor": {
    "Columns": [
      {
        "Name": "year",
        "Type": "bigint"
      },
      {
        "Name": "quarter",
        "Type": "bigint"
      }
    ],
    "Location": "s3://crawler-public-us-west-2/flight/2016/csv",
    "InputFormat": "org.apache.hadoop.mapred.TextInputFormat",
    "OutputFormat": "org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat",
    "Compressed": false,
    "NumberOfBuckets": -1,
    "SerdeInfo": {
      "SerializationLibrary": "org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe",
      "Parameters": {
        "field.delim": ",",
        "serialization.format": ","
      }
    }
  },
  "PartitionKeys": [
    {
      "Name": "mon",
      "Type": "string"
    }
  ],
  "TableType": "EXTERNAL_TABLE",
  "Parameters": {
    "EXTERNAL": "TRUE",
    "classification": "csv",
    "columnsOrdered": "true",
    "compressionType": "none",
    "delimiter": ",",
    "skip.header.line.count": "1",
    "typeOfData": "file"
  }
}
EOF

    # Replace placeholder with actual table name
    if ! sed -i "s/TABLE_NAME_PLACEHOLDER/$TABLE_NAME/g" "$TABLE_INPUT_FILE" 2>/dev/null; then
        echo "ERROR: Failed to substitute table name in JSON file" >&2
        rm -f "$TABLE_INPUT_FILE"
        exit 1
    fi

    # Validate JSON syntax before using it
    if ! jq empty "$TABLE_INPUT_FILE" 2>/dev/null; then
        echo "ERROR: Invalid JSON in table input file" >&2
        rm -f "$TABLE_INPUT_FILE"
        exit 1
    fi
}

# Function to create table
create_table() {
    echo "Step 2: Creating a table named $TABLE_NAME in database $DB_NAME"

    prepare_table_input

    if ! aws glue create-table \
        --database-name "$DB_NAME" \
        --table-input "file://${TABLE_INPUT_FILE}" \
        --region "$AWS_REGION" \
        --output json > /dev/null 2>&1; then
        echo "ERROR: Failed to create table $TABLE_NAME" >&2
        rm -f "$TABLE_INPUT_FILE"
        exit 1
    fi
    
    CREATED_RESOURCES+=("table:$TABLE_NAME")
    echo "Table $TABLE_NAME created successfully."
}

# Function to get and display table details
display_table_details() {
    echo "Step 3: Getting details of table $TABLE_NAME"
    
    if ! aws glue get-table \
        --database-name "$DB_NAME" \
        --name "$TABLE_NAME" \
        --region "$AWS_REGION" \
        --output json; then
        echo "ERROR: Failed to retrieve table details" >&2
        exit 1
    fi
}

# Function to display summary
display_summary() {
    echo ""
    echo "==========================================="
    echo "RESOURCES CREATED"
    echo "==========================================="
    echo "Database: $DB_NAME"
    echo "Table: $TABLE_NAME"
    echo "==========================================="
}

# Main execution flow
validate_prerequisites
create_database
create_table
display_table_details
display_summary

echo ""
echo "==========================================="
echo "CLEANUP CONFIRMATION"
echo "==========================================="
echo "Starting cleanup process..."

echo "Script completed at $(date)"