Why Binary Authorization for containers in GCP? - Purpose & Use Cases

The Big Idea

What if a single unchecked container image could bring down your entire app? Binary Authorization stops that risk automatically.

The Scenario

Imagine you have a team building container images for your app. You manually check each image before allowing it to run in your cloud environment. You rely on emails, chats, or spreadsheets to approve images. This process is slow and confusing.

The Problem

Manual approval is slow and easy to miss mistakes. Someone might approve a container with a security flaw or outdated code. It's hard to track who approved what and when. This can lead to security risks and downtime.

The Solution

Binary Authorization automates container image approval. It enforces rules so only trusted, verified images can run. This removes guesswork and human error. It keeps your cloud environment safe and reliable.

Before vs After

✗ Before

Check image manually -> Approve via email -> Deploy container

✓ After

Push image -> Binary Authorization verifies -> Container deploys automatically

What It Enables

It enables secure, automatic enforcement of trusted container images before deployment.

Real Life Example

A company uses Binary Authorization to block any container images that don't pass security scans or lack proper signatures, preventing unsafe code from reaching production.

Key Takeaways

Manual container approvals are slow and risky.

Binary Authorization automates and enforces trusted image deployment.

This improves security and speeds up delivery.

Practice

1. What is the main purpose of Binary Authorization in Google Cloud?

easy

A. To allow only trusted container images to run

B. To speed up container deployment

C. To monitor network traffic between containers

D. To automatically scale container clusters

Solution

1. Step 1: Understand Binary Authorization's role

   Binary Authorization is designed to protect cloud environments by ensuring only trusted container images are deployed.

2. Step 2: Identify the main function

   It uses policies and signatures to verify container images before they run, preventing untrusted code execution.

3. Final Answer:

   To allow only trusted container images to run -> Option A

4. Quick Check:

   Binary Authorization = Trusted container enforcement [OK]

Hint: Binary Authorization controls which containers can run [OK]

Common Mistakes:

• Confusing it with scaling or monitoring tools
• Thinking it speeds up deployment
• Assuming it manages network traffic

2. Which of the following is the correct way to enable Binary Authorization on a Google Kubernetes Engine (GKE) cluster?

easy

A. gcloud container clusters create my-cluster --enable-binauthz

B. gcloud container clusters create my-cluster --enable-auth-binary

C. gcloud container clusters create my-cluster --enable-binary-auth

D. gcloud container clusters create my-cluster --enable-binary-authorization

Solution

1. Step 1: Recall the correct flag for enabling Binary Authorization

   The official gcloud command uses the flag --enable-binary-authorization to enable this feature on a GKE cluster.

2. Step 2: Compare options

   Only gcloud container clusters create my-cluster --enable-binary-authorization uses the exact correct flag syntax; others are incorrect or invalid flags.

3. Final Answer:

   gcloud container clusters create my-cluster --enable-binary-authorization -> Option D

4. Quick Check:

   Enable Binary Authorization flag = --enable-binary-authorization [OK]

Hint: Look for the full phrase 'binary-authorization' in the flag [OK]

Common Mistakes:

• Using shortened or incorrect flag names
• Mixing up flag order or syntax
• Assuming 'binauthz' is the flag

3. Consider this policy snippet for Binary Authorization:

{
  "attestors": ["projects/my-project/attestors/my-attestor"],
  "defaultAdmissionRule": {
    "enforcementMode": "ENFORCED",
    "requireAttestationsBy": ["projects/my-project/attestors/my-attestor"]
  }
}

What happens if a container image is not signed by the specified attestor?

medium

A. The container image will be deployed but logged

B. The container image will be blocked from deployment

C. The container image will be deployed without checks

D. The container image will be automatically signed

Solution

1. Step 1: Analyze the enforcement mode

   The policy sets "enforcementMode" to "ENFORCED", meaning only images meeting the policy are allowed.

2. Step 2: Check attestation requirement

   The policy requires attestations by the specified attestor. Unsigned images do not meet this requirement.

3. Final Answer:

   The container image will be blocked from deployment -> Option B

4. Quick Check:

   Enforced mode + missing signature = block deployment [OK]

Hint: Enforced mode means no unsigned images allowed [OK]

Common Mistakes:

• Confusing enforcement with audit mode
• Thinking unsigned images are allowed with logs
• Assuming automatic signing happens

4. You configured Binary Authorization but your container deployments are failing unexpectedly. Which of the following is a likely cause?

medium

A. The attestor's public key is not correctly configured

B. The cluster does not have enough CPU resources

C. The container image is too large

D. The network firewall blocks container traffic

Solution

1. Step 1: Identify Binary Authorization failure reasons

   Binary Authorization failures often happen if the attestor's public key is missing or misconfigured, preventing signature verification.

2. Step 2: Eliminate unrelated causes

   CPU resources, image size, and network firewall issues do not directly cause Binary Authorization failures.

3. Final Answer:

   The attestor's public key is not correctly configured -> Option A

4. Quick Check:

   Signature verification fails if attestor key is wrong [OK]

Hint: Check attestor keys first when deployments fail [OK]

Common Mistakes:

• Blaming resource or network issues for auth failures
• Ignoring attestor key setup
• Assuming image size affects authorization

5. You want to test your Binary Authorization policy without blocking any container deployments. Which mode should you use and why?

hard

A. Disabled mode, to turn off Binary Authorization temporarily

B. Enforced mode, to block all untrusted images immediately

C. Audit mode, to log policy violations without blocking deployments

D. Strict mode, to require multiple attestations

Solution

1. Step 1: Understand Binary Authorization modes

   Audit mode allows policy violations to be logged but does not block container deployments, ideal for testing.

2. Step 2: Compare other modes

   Enforced mode blocks untrusted images, Disabled mode turns off checks, and Strict mode is not a standard mode.

3. Final Answer:

   Audit mode, to log policy violations without blocking deployments -> Option C

4. Quick Check:

   Audit mode = test without blocking [OK]

Hint: Use audit mode to test policies safely [OK]

Common Mistakes:

• Confusing audit with enforced mode
• Thinking disabled mode logs violations
• Assuming strict mode exists