Route 53 with ELB integration in AWS - Mini Project: Build & Apply

Route 53 with ELB integration

📖 Scenario: You are setting up a simple web application on AWS. You want to connect your domain name to your application load balancer so users can access your app using a friendly URL.

🎯 Goal: Build an AWS Route 53 configuration that creates a hosted zone and a DNS record pointing your domain to an existing Elastic Load Balancer (ELB).

📋 What You'll Learn

Create a hosted zone for the domain example.com in Route 53.

Create an alias A record in the hosted zone that points to the ELB DNS name my-load-balancer-1234567890.us-west-2.elb.amazonaws.com.

Use the AWS CLI JSON format for the Route 53 change batch.

Follow AWS best practices for alias records to ELB.

💡 Why This Matters

🌍 Real World

Connecting a domain name to an AWS Elastic Load Balancer is a common step in deploying web applications to make them accessible via friendly URLs.

💼 Career

Understanding Route 53 and ELB integration is essential for cloud engineers and DevOps professionals managing scalable web infrastructure on AWS.

1

Create a hosted zone for example.com

Write a JSON object called hosted_zone_config that defines a hosted zone with the name example.com and a caller reference unique-string-001.

AWS

# Define the hosted zone configuration JSON
# Your code here

Hint

The hosted zone needs a Name and a unique CallerReference string.

2

Add the ELB DNS name as a variable

Create a variable called elb_dns_name and set it to the string my-load-balancer-1234567890.us-west-2.elb.amazonaws.com.

AWS

{
  "hosted_zone_config": {
    "Name": "example.com",
    "CallerReference": "unique-string-001"
  }
}

# Define the ELB DNS name
# Your code here

Hint

Store the ELB DNS name as a string variable for reuse.

3

Create the Route 53 change batch JSON for alias record

Create a JSON object called change_batch that contains a Changes list with one change. This change should be an UPSERT action that creates an alias A record for example.com pointing to the ELB DNS name stored in elb_dns_name. Use the hosted zone ID Z3DZXE0Q79N41H for the ELB alias target. The record should have a TTL of 300 seconds.

AWS

{
  "hosted_zone_config": {
    "Name": "example.com",
    "CallerReference": "unique-string-001"
  },
  "elb_dns_name": "my-load-balancer-1234567890.us-west-2.elb.amazonaws.com"
}

# Create the change batch JSON for the alias record
# Your code here

Hint

Use the AliasTarget structure with HostedZoneId and DNSName for ELB alias records.

4

Add the hosted zone ID to the hosted zone config

Add the HostedZoneId field with value Z1D633PJN98FT9 to the hosted_zone_config object.

AWS

{
  "hosted_zone_config": {
    "Name": "example.com",
    "CallerReference": "unique-string-001"
  },
  "elb_dns_name": "my-load-balancer-1234567890.us-west-2.elb.amazonaws.com",
  "change_batch": {
    "Changes": [
      {
        "Action": "UPSERT",
        "ResourceRecordSet": {
          "Name": "example.com",
          "Type": "A",
          "AliasTarget": {
            "HostedZoneId": "Z3DZXE0Q79N41H",
            "DNSName": "my-load-balancer-1234567890.us-west-2.elb.amazonaws.com",
            "EvaluateTargetHealth": false
          },
          "TTL": 300
        }
      }
    ]
  }
}

# Add HostedZoneId to hosted_zone_config
# Your code here

Hint

The hosted zone config should include the hosted zone ID for your domain.

Practice

1. What is the main benefit of using a Route 53 alias record with an Elastic Load Balancer (ELB)?

easy

A. It allows you to point your domain directly to the ELB without using an IP address.

B. It automatically creates a backup server for your website.

C. It encrypts all traffic between users and the ELB.

D. It reduces the cost of running the ELB.

Solution

1. Step 1: Understand Route 53 alias records

   Alias records let you point your domain name to AWS resources like ELB without needing an IP address.

2. Step 2: Recognize ELB integration benefit

   This simplifies DNS management and handles ELB IP changes automatically.

3. Final Answer:

   It allows you to point your domain directly to the ELB without using an IP address. -> Option A

4. Quick Check:

   Alias record points domain to ELB without IP [OK]

Hint: Alias records link domains to ELB without IPs [OK]

Common Mistakes:

• Thinking alias records create backups
• Confusing alias with encryption
• Assuming alias reduces ELB cost

2. Which of the following is the correct way to create a Route 53 alias record pointing to an ELB in the AWS console?

easy

A. Create a CNAME record pointing to the ELB's IP address.

B. Create an A record and enter the ELB's IP address manually.

C. Create an A record and select 'Alias' with the ELB as the target.

D. Create a TXT record with the ELB's DNS name.

Solution

1. Step 1: Know Route 53 record types for ELB

   ELB does not have fixed IPs, so you cannot use IP addresses directly.

2. Step 2: Use alias A record

   Route 53 allows creating an A record with alias enabled, selecting the ELB DNS name as target.

3. Final Answer:

   Create an A record and select 'Alias' with the ELB as the target. -> Option C

4. Quick Check:

   Alias A record points to ELB DNS [OK]

Hint: Use alias A record, not IP or CNAME for ELB [OK]

Common Mistakes:

• Using IP address for ELB
• Choosing CNAME instead of alias A record
• Using TXT record incorrectly

3. Given a Route 53 setup with an alias record pointing to an ELB, what happens if the ELB becomes unhealthy and fails its health checks?

medium

A. Route 53 continues sending traffic to the ELB regardless of health status.

B. Route 53 automatically stops sending traffic to the ELB until it is healthy again.

C. Route 53 deletes the alias record automatically.

D. Route 53 redirects traffic to a backup IP address.

Solution

1. Step 1: Understand Route 53 health checks with ELB

   Route 53 alias records pointing to ELB do not automatically stop sending traffic if the ELB is unhealthy because ELB manages its own health and traffic routing internally.

2. Step 2: Behavior on ELB failure

   Route 53 continues to resolve the alias record to the ELB DNS name regardless of ELB health status; ELB itself stops routing traffic to unhealthy targets.

3. Final Answer:

   Route 53 continues sending traffic to the ELB regardless of health status. -> Option A

4. Quick Check:

   Route 53 alias records do not perform health-based routing for ELB [OK]

Hint: ELB manages health; Route 53 alias does not stop traffic [OK]

Common Mistakes:

• Thinking Route 53 stops traffic to unhealthy ELB
• Assuming Route 53 deletes records on failure
• Believing Route 53 redirects to IP automatically

4. You created a Route 53 alias record to an ELB, but your website is not reachable. Which of the following is the most likely cause?

medium

A. The domain name is missing a trailing dot in the alias record.

B. The alias record is set as a CNAME instead of an A record with alias enabled.

C. The alias record points to the ELB DNS name, but the ELB is in a different AWS region than the hosted zone.

D. The ELB does not have any registered healthy targets.

Solution

1. Step 1: Check ELB target health

   If ELB has no healthy targets, it cannot serve traffic, causing website unreachable.

2. Step 2: Verify alias record and region

   Alias records can point across regions; CNAME is invalid for alias; trailing dot is not required for alias.

3. Final Answer:

   The ELB does not have any registered healthy targets. -> Option D

4. Quick Check:

   Healthy targets needed for ELB to serve traffic [OK]

Hint: Check ELB target health if site unreachable [OK]

Common Mistakes:

• Confusing alias record type
• Assuming region mismatch breaks alias
• Thinking trailing dot is required

5. You want to configure Route 53 to route traffic to two ELBs in different regions for high availability. Which setup ensures traffic is sent only to healthy ELBs and balances load between them?

hard

A. Create two CNAME records with the same domain name pointing to each ELB's DNS name.

B. Create two alias A records with the same domain name, each pointing to one ELB, and enable health checks on both records.

C. Create a single alias A record pointing to the ELB in the primary region and manually switch to the other ELB if failure occurs.

D. Create two alias A records with different domain names and use a third DNS service to balance traffic.

Solution

1. Step 1: Use alias A records with health checks

   Route 53 supports multiple alias records with health checks to route traffic only to healthy ELBs.

2. Step 2: Load balancing across regions

   By creating two alias records with health checks, Route 53 can balance traffic and failover automatically.

3. Final Answer:

   Create two alias A records with the same domain name, each pointing to one ELB, and enable health checks on both records. -> Option B

4. Quick Check:

   Multiple alias records + health checks = HA and load balancing [OK]

Hint: Use multiple alias records with health checks for HA [OK]

Common Mistakes:

• Using CNAME for ELB alias
• Manual failover instead of health checks
• Using different domain names for ELBs