Set up for GKE clusters

This document shows you how to set up Binary Authorization for GKE clusters. It then shows you how to configure a sample Binary Authorization policy.

Before you begin

You must have GKE clusters registered with Connect. Binary Authorization supports the following environments.

GKE on Bare Metal
GKE on Bare Metal 1.14 or later.

GKE on VMware
GKE on VMware 1.4 or later.
The Binary Authorization service uses a public IP address, accessible through a regular internet connection. Configure your firewall rules for HTTPS to let the user cluster access the endpoint binaryauthorization.googleapis.com.

GKE on Bare Metal
Configure GKE on Bare Metal firewall rules.

GKE on VMware
Configure GKE on VMware firewall rules.
If you want to use centralized Cloud Audit Logs to view audit log entries, including those from Binary Authorization for GKE clusters, you must configure Cloud Audit Logs in your cluster configuration.

GKE on Bare Metal
Configure Cloud Audit Logs in GKE on Bare Metal.

GKE on VMware
Configure Cloud Audit Logs in GKE on VMware.
You must enable the Binary Authorization API as follows:
1. Go to Google Cloud console.
  
  Enable APIs
2. In the project drop-down list, select your Connect project. You can find this Google Cloud project in the gkeConnect section of your user cluster configuration file. This is the Google Cloud project that connects your user cluster to Google Cloud.

Set up Binary Authorization

In this section, you set up Binary Authorization for GKE clusters in your cluster.

Specify installation environment variables

To specify the environment variables, do the following:

Using Workload Identity

Specify your Connect project:
```
export PROJECT_ID=PROJECT_ID
```
Specify the Fleet membership ID of your cluster:
```
export MEMBERSHIP_ID=MEMBERSHIP_ID
```

Using service account key

Specify your Connect project:
```
export PROJECT_ID=PROJECT_ID
```
Replace PROJECT_ID with the Google Cloud project in the gkeConnect section of your user cluster configuration file.
Specify the path of the user cluster's kubeconfig file:
```
export KUBECONFIG=PATH
```
Replace PATH with the path of your user cluster kubeconfig file.
Choose a name for the Binary Authorization API access service account:
```
export SA_NAME=SERVICE_ACCOUNT_NAME
```
Replace SERVICE_ACCOUNT_NAME with the service account name of your choice. The Binary Authorization Module uses this service account to access the Binary Authorization API.
Specify the path to the service account key file you download later in this guide:
```
export SA_JSON_PATH=SA_KEY_FILE_PATH
```
Replace SA_KEY_FILE_PATH with the path of the JSON key file for the service account.

Install the Binary Authorization module in your user cluster

To install the Binary Authorization module, do the following:

Using Workload Identity

Fleet Workload Identity lets the workloads in your cluster authenticate to Google without requiring you to download, manually rotate, and generally manage Google Cloud service account keys. You can find out more about how fleet Workload Identity works and the advantages of using it in Use fleet Workload Identity.

Grant the binaryauthorization.policyEvaluator role to the Kubernetes service account on your Connect project:

gcloud projects add-iam-policy-binding ${PROJECT_ID} \
    --member="serviceAccount:${PROJECT_ID}.svc.id.goog[binauthz-system/binauthz-admin]" \
    --role="roles/binaryauthorization.policyEvaluator"

Create a working directory:
1. Make a directory called binauthz.
2. Change to the directory.
Download the manifest-wi-0.2.6.yaml.tmpl file, which you use to install the Binary Authorization Module in your GKE clusters user cluster:
GKE on Bare Metal
```
gsutil cp gs://anthos-baremetal-release/binauthz/manifest-wi-0.2.6.yaml.tmpl .
```
GKE on VMware
```
gsutil cp gs://gke-on-prem-release/binauthz/manifest-wi-0.2.6.yaml.tmpl .
```

Substitute the environment variables in the template:

envsubst < manifest-wi-0.2.6.yaml.tmpl > manifest-0.2.6.yaml

Install the Binary Authorization Module in your user cluster:
```
kubectl apply -f manifest-0.2.6.yaml
```

Verify the Deployment was created:

kubectl get pod --namespace binauthz-system

You see the Pod binauthz-module-deployment-* listed with Status of Running and 1/1 Pods ready, similar to this output:

NAME                                          READY   STATUS    RESTARTS   AGE
binauthz-module-deployment-5fddf9594f-qjprz   1/1     Running   0          11s

Using service account key

Set the default project for the Google Cloud CLI:
```
gcloud config set project ${PROJECT_ID}
```
Create a Binary Authorization API access service account:
```
gcloud iam service-accounts create ${SA_NAME}
```

Grant the binaryauthorization.policyEvaluator role to the Binary Authorization API access service account on your Connect project:

gcloud projects add-iam-policy-binding ${PROJECT_ID}\
    --member="serviceAccount:${SA_NAME}@${PROJECT_ID}.iam.gserviceaccount.com" \
    --role="roles/binaryauthorization.policyEvaluator"

Create a working directory:
1. Make a directory called binauthz.
2. Change to the directory.
Download the manifest-0.2.6.yaml file, which you use to install the Binary Authorization Module in your GKE clusters user cluster:
anthos_clusters_on_bare_metal
```
gsutil cp gs://anthos-baremetal-release/binauthz/manifest-0.2.6.yaml .
```
anthos_clusters_on_vmware
```
gsutil cp gs://gke-on-prem-release/binauthz/manifest-0.2.6.yaml .
```

Create a YAML file for thebinauthz-system namespace.

Copy the following to a file called namespace.yaml:

apiVersion: v1
kind: Namespace
metadata:
  labels:
    control-plane: binauthz-controller
  name: binauthz-system

Create the namespace in your user cluster:
```
kubectl apply -f namespace.yaml
```
You see output similar to the following:
```
namespace/binauthz-system created
```

Download a JSON key file for your service account:

gcloud iam service-accounts keys create ${SA_JSON_PATH} --iam-account ${SA_NAME}@${PROJECT_ID}.iam.gserviceaccount.com

Save the service account key as a Kubernetes Secret in your user cluster:

kubectl --namespace binauthz-system create secret generic binauthz-sa --from-file=key.json=${SA_JSON_PATH}

Install the Binary Authorization Module in your user cluster:
```
kubectl apply -f manifest-0.2.6.yaml
```

Verify the Deployment was created:

kubectl get pod --namespace binauthz-system

You see the Pod binauthz-module-deployment-* listed with Status of Running and 1/1 Pods ready, similar to this output:

NAME                                          READY   STATUS    RESTARTS   AGE
binauthz-module-deployment-5fddf9594f-qjprz   1/1     Running   0          11s

Set up and use Binary Authorization policies

This section shows you how to set up and use Binary Authorization policies for GKE clusters.

In each example, you configure the policy and then test it by attempting to deploy a container image in your GKE cluster.

Allow all

This section demonstrates a success case. You configure the Binary Authorization policy so that a container image satisfies the policy and is deployed.

In Google Cloud, do the following:

Console

In the Google Cloud console, go to the Binary Authorization page.

Go to Binary Authorization
Make sure to select your Connect project ID.
Click Edit Policy.
Under Project default rule, select Allow all images.
Click Save Policy.

gcloud

Set the PROJECT_ID for your Connect project. You can find this project ID in the gkeConnect field in your user cluster configuration file.
```
export PROJECT_ID=PROJECT_ID
```
Set the default Google Cloud project.
```
gcloud config set project ${PROJECT_ID}
```

Export the policy YAML file to your local system:

gcloud container binauthz policy export  > policy.yaml

Your YAML file looks like the following:

admissionWhitelistPatterns:
- namePattern: gcr.io/google_containers/*
- namePattern: gcr.io/google-containers/*
- namePattern: k8s.gcr.io/**
- namePattern: gke.gcr.io/**
- namePattern: gcr.io/stackdriver-agents/*
globalPolicyEvaluationMode: ENABLE
defaultAdmissionRule:
  evaluationMode: ALWAYS_ALLOW
  enforcementMode: ENFORCED_BLOCK_AND_AUDIT_LOG
name: projects/<var>PROJECT_ID</var>/policy

Edit policy.yaml.
Set evaluationMode to ALWAYS_ALLOW.
If you have a requireAttestationsBy block in the file, delete this block.
Save the file.

Import policy.yaml as follows:

gcloud container binauthz policy import policy.yaml

On your GKE clusters admin workstation, do the following:

Create a manifest file for a Pod.

Save the following to a file called pod.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: test-pod
spec:
  containers:
  - name: test-container
    image: gcr.io/google-samples/hello-app@sha256:c62ead5b8c15c231f9e786250b07909daf6c266d0fcddd93fea882eb722c3be4

Create the Pod:
```
kubectl apply -f pod.yaml
```
You see that the Pod was successfully deployed.
Delete the Pod:
```
kubectl delete -f pod.yaml
```

Disallow all

This section demonstrates a failure case. In this section, you configure the default policy to disallow your container image from being deployed.

In Google Cloud do the following:

Console

In the Google Cloud console, go to the Binary Authorization page.

Go to Binary Authorization
Make sure your Connect project is selected.
Click Edit Policy.
Under Project default rule, select Disallow all images.
Click Save policy.

gcloud

Set the PROJECT_ID to your Connect project ID.
```
export PROJECT_ID=PROJECT_ID
```

Set the default Google Cloud project.

gcloud config set project ${PROJECT_ID}

Export the policy YAML file:

gcloud container binauthz policy export  > policy.yaml

Edit policy.yaml.
Set evaluationMode to ALWAYS_DENY.
If you have a requireAttestationsBy block in the file, delete this block.
Save the file.

Import policy.yaml as follows:

gcloud container binauthz policy import policy.yaml

On your GKE clusters admin workstation, do the following:

Create a manifest file for a Pod.

Save the following to a file called pod.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: test-pod
spec:
  containers:
  - name: test-container
    image: gcr.io/google-samples/hello-app@sha256:c62ead5b8c15c231f9e786250b07909daf6c266d0fcddd93fea882eb722c3be4

Create the Pod:

kubectl apply -f pod.yaml

You see that the Pod was was blocked from being deployed. The output looks like the following:

Error from server (VIOLATES_POLICY): error when creating "pod.yaml": admission webhook "binaryauthorization.googleapis.com" denied the request: Denied by default admission rule. Overridden by evaluation mode

Get the user cluster resource ID

This section shows you how to compose the cluster resource ID for your user cluster. In your Binary Authorization policy, you can create cluster-specific rules. You associate these rules with a cluster-specific resource ID, which is based on your cluster ID.

You get the resource ID as follows:

Console

In the Google Cloud console, go to the GKE Enterprise Clusters page.

Go to Clusters
Select the Connect project ID for GKE clusters. You can find this project ID in the gkeConnect section of your user cluster configuration file.
Under Anthos Managed Clusters, find your cluster ID under the Name column.
To create the resource ID, add the prefix global. to the cluster ID so that the resource ID has the following format: global.CLUSTER_ID.

gcloud

Use SSH to connect to your GKE clusters admin workstation.
On the admin workstation, run the following command:
```
kubectl get membership -o yaml
```

Get the cluster ID from spec.owner.id field of the output. Example output follows:

apiVersion: v1
items:
- apiVersion: hub.gke.io/v1
  kind: Membership
  ...
  spec:
    owner:
      id: //gkehub.googleapis.com/projects/PROJECT_NUMBER/locations/global/memberships/my-cluster-id

In the example output, the cluster ID is my-cluster-id.

To create the resource ID, add the prefix global. to the cluster ID. In the example, the resource ID is global.my-cluster-id.

You use this resource ID when you define cluster-specific rules. Learn how to set cluster-specific rules by using the Google Cloud console or the gcloud CLI.

Update the failure policy

The Binary Authorization Module webhook can be configured to fail open or fail close.

Fail close

To update the failure policy to fail close, do the following:

Edit the manifest-0.2.6.yaml file and set failurePolicy to Fail

Re-enable the webhook:

kubectl apply -f manifest-0.2.6.yaml

You see output similar to the following:

serviceaccount/binauthz-admin unchanged
role.rbac.authorization.k8s.io/binauthz-role configured
clusterrole.rbac.authorization.k8s.io/binauthz-role configured
rolebinding.rbac.authorization.k8s.io/binauthz-rolebinding unchanged
clusterrolebinding.rbac.authorization.k8s.io/binauthz-rolebinding unchanged
secret/binauthz-tls unchanged
service/binauthz unchanged
deployment.apps/binauthz-module-deployment unchanged
validatingwebhookconfiguration.admissionregistration.k8s.io/binauthz-validating-webhook-configuration configured

Fail open

To update the failure policy to fail open, do the following:

Edit the manifest-0.2.6.yaml file and set failurePolicy to Ignore

Re-enable the webhook:

kubectl apply -f manifest-0.2.6.yaml

You see output similar to the following:

serviceaccount/binauthz-admin unchanged
role.rbac.authorization.k8s.io/binauthz-role configured
clusterrole.rbac.authorization.k8s.io/binauthz-role configured
rolebinding.rbac.authorization.k8s.io/binauthz-rolebinding unchanged
clusterrolebinding.rbac.authorization.k8s.io/binauthz-rolebinding unchanged
secret/binauthz-tls unchanged
service/binauthz unchanged
deployment.apps/binauthz-module-deployment unchanged
validatingwebhookconfiguration.admissionregistration.k8s.io/binauthz-validating-webhook-configuration configured

To learn more, see webhook failure policy.

Clean up

The following code sample shows how to disable the webhook:

kubectl delete ValidatingWebhookConfiguration/binauthz-validating-webhook-configuration

The following code sample shows how to re-enable the webhook:
```
kubectl apply -f manifest-0.2.6.yaml
```
The following code sample shows how to delete all of the resources related to Binary Authorization:
```
kubectl delete -f manifest-0.2.6.yaml
kubectl delete namespace binauthz-system
```

What's next

To check policy compliance at Pod creation time without actually blocking the Pod from being created, see Enable dry run.
To force a Pod to be created that the Binary Authorization enforcer would otherwise block, see Use breakglass.
Use the built-by-cloud-build attestor to deploy only images built by Cloud Build (Preview).
To implement an attestor-based Binary Authorization policy, see the following:
- Configure a policy using the Google Cloud console or the command-line tool. Set the default or cluster-specific rule to require attestations.
- Create an attestor using the Google Cloud console or the command-line tool.
- Create an attestation.
To see log events related to Binary Authorization for GKE clusters, see View Cloud Audit Logs events.
Monitor metrics.

Set up for GKE clusters

Before you begin

GKE on Bare Metal

GKE on VMware

GKE on Bare Metal

GKE on VMware

GKE on Bare Metal

GKE on VMware

Set up Binary Authorization

Specify installation environment variables

Using Workload Identity

Using service account key

Install the Binary Authorization module in your user cluster

Using Workload Identity

GKE on Bare Metal

GKE on VMware

Using service account key

anthos_clusters_on_bare_metal

anthos_clusters_on_vmware

Set up and use Binary Authorization policies

Allow all

Console

gcloud

Disallow all

Console

gcloud

Get the user cluster resource ID

Console

gcloud

Update the failure policy

Fail close

Fail open

Clean up

What's next