Binary Authorization for containers in GCP - Step-by-Step Execution

Process Flow - Binary Authorization for containers

Developer builds container image

↓

Image pushed to Container Registry

↓

Binary Authorization checks image signature

↓

Image deployed

↓

Container runs with verified image

This flow shows how Binary Authorization checks container images before deployment, allowing only trusted images to run.

Execution Sample

GCP

1. Build container image
2. Push image to registry
3. Deploy with Binary Authorization enabled
4. Binary Authorization verifies signature
5. Deployment allowed or blocked

This sequence shows the steps from building a container image to deployment with Binary Authorization enforcing image trust.

Process Table

Step	Action	Image Signature Present?	Verification Result	Deployment Outcome
1	Build container image	No	N/A	N/A
2	Push image to registry	No	N/A	N/A
3	Deploy with Binary Authorization	Yes	Signature Verified	Deployment Allowed
4	Deploy with Binary Authorization	No	Signature Missing	Deployment Blocked

💡 Deployment stops if image signature is missing or invalid, ensuring only trusted images run.

Status Tracker

Variable	Start	After Step 2	After Step 3 (Valid Signature)	After Step 4 (Missing Signature)
Image Signature Present	No	No	Yes	No
Verification Result	N/A	N/A	Signature Verified	Signature Missing
Deployment Outcome	N/A	N/A	Allowed	Blocked

Key Moments - 3 Insights

Why does deployment get blocked even if the image is pushed to the registry?

Because Binary Authorization requires a valid signature on the image before deployment. Pushing alone does not add a signature (see execution_table step 4).

What happens if the image has a valid signature?

Binary Authorization verifies the signature and allows deployment to proceed (see execution_table step 3).

Is it possible to deploy an unsigned image with Binary Authorization enabled?

No, deployment is blocked if the image lacks a valid signature to ensure security (see execution_table step 4).

Visual Quiz - 3 Questions

Look at the execution table, what is the deployment outcome when the image signature is verified?

A Deployment Blocked

B Deployment Pending

C Deployment Allowed

D No Deployment

💡 Hint

Check the row where Verification Result is 'Signature Verified' in the execution_table.

At which step does Binary Authorization block deployment?

A Step 2

B Step 4

C Step 3

D Step 1

💡 Hint

Look for the step where Deployment Outcome is 'Deployment Blocked' in the execution_table.

If the image signature is missing after pushing, what will Binary Authorization do during deployment?

A Block deployment

B Ignore signature and deploy

C Allow deployment

D Request manual approval

💡 Hint

Refer to the Verification Result and Deployment Outcome columns in the execution_table for missing signatures.

Concept Snapshot

Binary Authorization ensures only trusted container images run.
It checks image signatures before deployment.
Unsigned or invalid images are blocked.
This protects your environment from unverified code.
Enable it in your GCP cluster for secure deployments.

Full Transcript

Binary Authorization is a security feature in Google Cloud that checks container images before they run. Developers build and push images to a registry. When deploying, Binary Authorization verifies if the image has a valid signature. If yes, deployment proceeds. If not, deployment is blocked. This process helps keep your containers safe by only allowing trusted images to run.

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