How Do I Implement AWS Glue Crawlers With Pulumi?

Introduction

AWS Glue is a fully managed ETL (Extract, Transform, Load) service that makes it easy to prepare and load data for analytics. AWS Glue Crawlers are a key component of this service, as they automatically populate the AWS Glue Data Catalog with metadata about data sources. In this guide, we will demonstrate how to implement AWS Glue Crawlers using Pulumi, a modern infrastructure as code tool. We will walk through the process of setting up a Glue Crawler to catalog data stored in an S3 bucket.

Step-by-Step Implementation

Here’s the detailed Pulumi program written in TypeScript:

import * as pulumi from "@pulumi/pulumi";
import * as aws from "@pulumi/aws";

// Create an S3 bucket to store data
const dataBucket = new aws.s3.Bucket("dataBucket");

// Create an IAM role for the Glue Crawler
const glueRole = new aws.iam.Role("glueRole", {
    assumeRolePolicy: {
        Version: "2012-10-17",
        Statement: [{
            Action: "sts:AssumeRole",
            Effect: "Allow",
            Principal: {
                Service: "glue.amazonaws.com",
            },
        }],
    },
});

// Attach the AWS Glue service policy to the role
const gluePolicyAttachment = new aws.iam.RolePolicyAttachment("gluePolicyAttachment", {
    role: glueRole.name,
    policyArn: "arn:aws:iam::aws:policy/service-role/AWSGlueServiceRole",
});

// Create a Glue Database
const glueDatabase = new aws.glue.CatalogDatabase("glueDatabase", {
    name: "example_database",
});

// Create a Glue Crawler
const glueCrawler = new aws.glue.Crawler("glueCrawler", {
    role: glueRole.arn,
    databaseName: glueDatabase.name,
    s3Targets: [{
        path: dataBucket.arn,
    }],
    schedule: "cron(0 12 * * ? *)", // Schedule to run daily at 12 PM UTC
    classifiers: [],
    configuration: JSON.stringify({
        Version: 1.0,
        CrawlerOutput: {
            Partitions: {
                AddOrUpdateBehavior: "InheritFromTable",
            },
        },
    }),
    schemaChangePolicy: {
        deleteBehavior: "LOG",
        updateBehavior: "UPDATE_IN_DATABASE",
    },
});

// Export the name of the S3 bucket and Glue Crawler
export const bucketName = dataBucket.bucket;
export const crawlerName = glueCrawler.name;

Explanation of Implementation Steps

1. Create an S3 Bucket: We begin by creating an S3 bucket where the data to be cataloged is stored.
2. Create an IAM Role: Next, we create an IAM role with a policy that allows AWS Glue to assume this role.
3. Attach Glue Service Policy: We attach the AWS Glue service role policy to the IAM role to allow it to perform Glue operations.
4. Create a Glue Database: A Glue Database is created to store the metadata of the cataloged data.
5. Create a Glue Crawler: Finally, we create a Glue Crawler with a daily schedule. This crawler targets the S3 bucket and updates the Glue Data Catalog with metadata.

Key Points

• AWS Glue Crawlers automate the process of cataloging data stored in S3.
• Pulumi allows for the infrastructure to be defined and managed using code.
• The IAM role is essential for Glue to perform its operations securely.
• Scheduling the crawler ensures that the data catalog is regularly updated.

Conclusion

Implementing AWS Glue Crawlers with Pulumi simplifies the process of managing data catalogs in AWS. By automating the metadata extraction and cataloging process, organizations can maintain up-to-date data catalogs with minimal manual effort. This setup is crucial for data-driven applications that rely on accurate and timely metadata.