ECR for container image registry in AWS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an Amazon ECR repository named 'my-repo'.

AWS

aws ecr create-repository --repository-name [1]

Drag options to blanks, or click blank then click option'

Atest-repo

Bdocker-images

Ccontainer-registry

Dmy-repo

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different repository name than 'my-repo'.

Leaving the repository name blank.

The command creates an ECR repository with the specified name. Here, 'my-repo' is the correct repository name.

2fill in blank

medium

Complete the command to authenticate Docker to your Amazon ECR registry.

AWS

aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin [1].dkr.ecr.us-east-1.amazonaws.com

Drag options to blanks, or click blank then click option'

A123456789012

B111111111111

C999999999999

D000000000000

Attempts:

3 left

💡 Hint

Common Mistakes

Using an incorrect or incomplete account ID.

Omitting the account ID.

The AWS account ID is required to form the full ECR registry URI. '123456789012' is the example account ID here.

3fill in blank

hard

Fix the error in the command to tag a Docker image before pushing it to ECR.

AWS

docker tag my-image:latest [1].dkr.ecr.us-east-1.amazonaws.com/my-repo:latest

Drag options to blanks, or click blank then click option'

Alatest

Bmy-image

C123456789012

Dmy-repo

Attempts:

3 left

💡 Hint

Common Mistakes

Using the image name or tag instead of the account ID.

Omitting the account ID in the tag.

The tag must include the AWS account ID to specify the full ECR repository URI.

4fill in blank

hard

Fill both blanks to push a Docker image to the ECR repository.

AWS

docker push [1].dkr.ecr.us-east-1.amazonaws.com/[2]:latest

Drag options to blanks, or click blank then click option'

A123456789012

Bmy-repo

Clatest

Dmy-image

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the repository name and account ID.

Using image tag or name in place of repository name.

The first blank is the AWS account ID for the registry URI. The second blank is the repository name where the image is pushed.

5fill in blank

hard

Fill all three blanks to create a lifecycle policy JSON that expires images older than 30 days.

AWS

{
  "rules": [
    {
      "rulePriority": [1],
      "description": "Expire images older than 30 days",
      "selection": {
        "tagStatus": "[2]",
        "countType": "[3]",
        "countUnit": "days",
        "countNumber": 30
      },
      "action": {
        "type": "expire"
      }
    }
  ]
}

Drag options to blanks, or click blank then click option'

A1

Btagged

CsinceImagePushed

Duntagged

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'untagged' instead of 'tagged' for tagStatus.

Using 'countType' values other than 'sinceImagePushed'.

Setting rulePriority to 0 or a non-integer.

The rulePriority is 1 for the first rule. The tagStatus is 'tagged' to select tagged images. The countType 'sinceImagePushed' means counting days since the image was pushed.

Practice

1. What is the primary purpose of AWS Elastic Container Registry (ECR)?

easy

A. To store and manage container images securely

B. To run containerized applications

C. To monitor AWS cloud resources

D. To provide virtual machines for deployment

Solution

1. Step 1: Understand ECR's role

   AWS ECR is designed to store container images safely and manage them.

2. Step 2: Differentiate from other services

   Running containers is done by ECS or EKS, not ECR. Monitoring and VMs are unrelated.

3. Final Answer:

   To store and manage container images securely -> Option A

4. Quick Check:

   ECR = Container image storage [OK]

Hint: ECR stores images, ECS/EKS run containers [OK]

Common Mistakes:

• Confusing ECR with ECS or EKS
• Thinking ECR runs containers
• Assuming ECR monitors resources

2. Which AWS CLI command correctly creates a new ECR repository named my-app?

easy

A. aws ecr make-repo --repository my-app

B. aws ecr new-repository --name my-app

C. aws ecr create-repository --repository-name my-app

D. aws ecr init-repository --repo my-app

Solution

1. Step 1: Recall AWS CLI syntax for ECR

   The correct command to create a repository is aws ecr create-repository --repository-name <name>.

2. Step 2: Check options for correctness

   Options B, C, and D use invalid commands or flags not recognized by AWS CLI.

3. Final Answer:

   aws ecr create-repository --repository-name my-app -> Option C

4. Quick Check:

   Create repo command = aws ecr create-repository --repository-name my-app [OK]

Hint: Use 'create-repository' with '--repository-name' flag [OK]

Common Mistakes:

• Using incorrect command verbs like 'new' or 'make'
• Wrong flag names like '--name' or '--repo'
• Assuming 'init-repository' is valid

3. Given this AWS CLI command output snippet after pushing an image to ECR, what does the imageScanStatus value IN_PROGRESS indicate?

{
  "imageId": {"imageTag": "v1"},
  "imageScanStatus": {"status": "IN_PROGRESS"}
}

medium

A. The image scan for vulnerabilities is currently running

B. The image scan has completed with no issues

C. The image push failed due to scan errors

D. The image is not scanned because scanning is disabled

Solution

1. Step 1: Understand imageScanStatus meaning

   The status IN_PROGRESS means the scan is currently running on the image.

2. Step 2: Eliminate other options

   Completed scans show COMPLETE, failures show FAILED, and disabled scanning shows no status.

3. Final Answer:

   The image scan for vulnerabilities is currently running -> Option A

4. Quick Check:

   IN_PROGRESS = scan running [OK]

Hint: IN_PROGRESS means scan is running, not done [OK]

Common Mistakes:

• Assuming IN_PROGRESS means scan passed
• Confusing scan failure with in-progress status
• Thinking scanning is disabled

4. You tried to push a container image to ECR but got an error: denied: Your authorization token has expired. What is the most likely fix?

medium

A. Restart the AWS CLI tool

B. Delete the repository and create a new one

C. Change the image tag and push again

D. Run aws ecr get-login-password again to refresh credentials

Solution

1. Step 1: Identify cause of authorization token error

   ECR login tokens expire after 12 hours, so pushing images requires fresh tokens.

2. Step 2: Refresh credentials properly

   Running aws ecr get-login-password and logging in again refreshes the token.

3. Final Answer:

   Run aws ecr get-login-password again to refresh credentials -> Option D

4. Quick Check:

   Expired token fix = refresh login [OK]

Hint: Refresh ECR login token before pushing images [OK]

Common Mistakes:

• Deleting repository unnecessarily
• Changing image tag won't fix auth
• Restarting CLI doesn't refresh token

5. You want to ensure that only images with specific tags can be overwritten in your ECR repository. Which ECR feature helps enforce this?

hard

A. VPC endpoints

B. Image tag immutability

C. Lifecycle policies

D. Cross-region replication

Solution

1. Step 1: Understand tag immutability

   Image tag immutability prevents overwriting images with the same tag, protecting specific versions.

2. Step 2: Differentiate from other features

   Lifecycle policies manage image cleanup, VPC endpoints control network access, replication copies images across regions.

3. Final Answer:

   Image tag immutability -> Option B

4. Quick Check:

   Prevent tag overwrite = immutability [OK]

Hint: Use tag immutability to block overwrites [OK]

Common Mistakes:

• Confusing lifecycle policies with immutability
• Thinking VPC endpoints control tags
• Assuming replication affects tag overwrite