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Azure

Cloud API Adaptor (CAA) on Azure

This documentation will walk you through setting up CAA (a.k.a. Peer Pods) on Azure Kubernetes Service (AKS). It explains how to deploy:

  • A single worker node Kubernetes cluster using Azure Kubernetes Service (AKS)
  • CAA on that Kubernetes cluster
  • An Nginx pod backed by CAA pod VM

Pre-requisites

Install Azure CLI

Follow the instructions here to install Azure CLI.

Install kubectl

Follow the instructions here to install kubectl.

Azure login

There are a bunch of steps that require you to be logged into your Azure account:

az login

Retrieve your “Subscription ID” and set your preferred region:

export CAA_VERSION="0.8.0"
export AZURE_SUBSCRIPTION_ID=$(az account show --query id --output tsv)
export AZURE_REGION="eastus"

Resource group

Note: Skip this step if you already have a resource group you want to use. Please, export the resource group name in the AZURE_RESOURCE_GROUP environment variable.

Create an Azure resource group by running the following command:

export AZURE_RESOURCE_GROUP="caa-rg-$(date '+%Y%m%b%d%H%M%S')"

az group create \
  --name "${AZURE_RESOURCE_GROUP}" \
  --location "${AZURE_REGION}"

Download the CAA configs

curl -LO "https://github.com/confidential-containers/cloud-api-adaptor/archive/refs/tags/v${CAA_VERSION}.tar.gz"
tar -xvzf "v${CAA_VERSION}.tar.gz"
cd "cloud-api-adaptor-${CAA_VERSION}"

Deploy Kubernetes using AKS

Make changes to the following environment variable as you see fit:

export CLUSTER_NAME="caa-$(date '+%Y%m%b%d%H%M%S')"
export AKS_WORKER_USER_NAME="azuser"
export AKS_RG="${AZURE_RESOURCE_GROUP}-aks"
export SSH_KEY=~/.ssh/id_rsa.pub

Note: Optionally, deploy the worker nodes into an existing Azure Virtual Network (VNet) and Subnet by adding the following flag: --vnet-subnet-id $SUBNET_ID.

Deploy AKS with single worker node to the same resource group you created earlier:

az aks create \
  --resource-group "${AZURE_RESOURCE_GROUP}" \
  --node-resource-group "${AKS_RG}" \
  --name "${CLUSTER_NAME}" \
  --enable-oidc-issuer \
  --enable-workload-identity \
  --location "${AZURE_REGION}" \
  --node-count 1 \
  --node-vm-size Standard_F4s_v2 \
  --nodepool-labels node.kubernetes.io/worker= \
  --ssh-key-value "${SSH_KEY}" \
  --admin-username "${AKS_WORKER_USER_NAME}" \
  --os-sku Ubuntu

Download kubeconfig locally to access the cluster using kubectl:

az aks get-credentials \
  --resource-group "${AZURE_RESOURCE_GROUP}" \
  --name "${CLUSTER_NAME}"

Deploy CAA

Note: If you are using Calico Container Network Interface (CNI) on the Kubernetes cluster, then, configure Virtual Extensible LAN (VXLAN) encapsulation for all inter workload traffic.

User assigned identity and federated credentials

CAA needs privileges to talk to Azure API. This privilege is granted to CAA by associating a workload identity to the CAA service account. This workload identity (a.k.a. user assigned identity) is given permissions to create VMs, fetch images and join networks in the next step.

Note: If you use an existing AKS cluster it might need to be configured to support workload identity and OpenID Connect (OIDC), please refer to the instructions in this guide.

Start by creating an identity for CAA:

export AZURE_WORKLOAD_IDENTITY_NAME="caa-identity"

az identity create \
  --name "${AZURE_WORKLOAD_IDENTITY_NAME}" \
  --resource-group "${AZURE_RESOURCE_GROUP}" \
  --location "${AZURE_REGION}"

export USER_ASSIGNED_CLIENT_ID="$(az identity show \
  --resource-group "${AZURE_RESOURCE_GROUP}" \
  --name "${AZURE_WORKLOAD_IDENTITY_NAME}" \
  --query 'clientId' \
  -otsv)"

Annotate the CAA Service Account with the workload identity’s CLIENT_ID and make the CAA daemonset use workload identity for authentication:

cat <<EOF > install/overlays/azure/workload-identity.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: cloud-api-adaptor-daemonset
  namespace: confidential-containers-system
spec:
  template:
    metadata:
      labels:
        azure.workload.identity/use: "true"
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: cloud-api-adaptor
  namespace: confidential-containers-system
  annotations:
    azure.workload.identity/client-id: "$USER_ASSIGNED_CLIENT_ID"
EOF

AKS resource group permissions

For CAA to be able to manage VMs assign the identity VM and Network contributor roles, privileges to spawn VMs in $AZURE_RESOURCE_GROUP and attach to a VNet in $AKS_RG.

az role assignment create \
  --role "Virtual Machine Contributor" \
  --assignee "$USER_ASSIGNED_CLIENT_ID" \
  --scope "/subscriptions/${AZURE_SUBSCRIPTION_ID}/resourcegroups/${AZURE_RESOURCE_GROUP}"

az role assignment create \
  --role "Reader" \
  --assignee "$USER_ASSIGNED_CLIENT_ID" \
  --scope "/subscriptions/${AZURE_SUBSCRIPTION_ID}/resourcegroups/${AZURE_RESOURCE_GROUP}"

az role assignment create \
  --role "Network Contributor" \
  --assignee "$USER_ASSIGNED_CLIENT_ID" \
  --scope "/subscriptions/${AZURE_SUBSCRIPTION_ID}/resourcegroups/${AKS_RG}"

Create the federated credential for the CAA ServiceAccount using the OIDC endpoint from the AKS cluster:

export AKS_OIDC_ISSUER="$(az aks show \
  --name "$CLUSTER_NAME" \
  --resource-group "${AZURE_RESOURCE_GROUP}" \
  --query "oidcIssuerProfile.issuerUrl" \
  -otsv)"

az identity federated-credential create \
  --name caa-fedcred \
  --identity-name caa-identity \
  --resource-group "${AZURE_RESOURCE_GROUP}" \
  --issuer "${AKS_OIDC_ISSUER}" \
  --subject system:serviceaccount:confidential-containers-system:cloud-api-adaptor \
  --audience api://AzureADTokenExchange

AKS subnet ID

Fetch the AKS created VNet name:

export AZURE_VNET_NAME=$(az network vnet list \
  --resource-group "${AKS_RG}" \
  --query "[0].name" \
  --output tsv)

Export the Subnet ID to be used for CAA daemonset deployment:

export AZURE_SUBNET_ID=$(az network vnet subnet list \
  --resource-group "${AKS_RG}" \
  --vnet-name "${AZURE_VNET_NAME}" \
  --query "[0].id" \
  --output tsv)

CAA pod VM image

Export this environment variable to use for the peer pod VM:

export AZURE_IMAGE_ID="/CommunityGalleries/cococommunity-42d8482d-92cd-415b-b332-7648bd978eff/Images/peerpod-podvm-ubuntu2204-cvm-snp/Versions/${CAA_VERSION}"

Note:

  • If you want to use the nightly build of pod VM image then follow the instructions here.
  • If you want to build the pod VM image yourself then follow the instructions here.

CAA container image

export CAA_IMAGE="quay.io/confidential-containers/cloud-api-adaptor"
export CAA_TAG="d4496d008b65c979a4d24767979a77ed1ba21e76"

Note: If you have made changes to the CAA code and you want to deploy those changes then follow these instructions to build the container image. Once the image is built export the environment variables accordingly.

Populate the kustomization.yaml file

Replace the values as needed for the following environment variables:

Note: For non-Confidential VMs use AZURE_INSTANCE_SIZE="Standard_D2as_v5".

Run the following command to update the kustomization.yaml file:

cat <<EOF > install/overlays/azure/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
bases:
- ../../yamls
images:
- name: cloud-api-adaptor
  newName: "${CAA_IMAGE}"
  newTag: "${CAA_TAG}"
generatorOptions:
  disableNameSuffixHash: true
configMapGenerator:
- name: peer-pods-cm
  namespace: confidential-containers-system
  literals:
  - CLOUD_PROVIDER="azure"
  - AZURE_SUBSCRIPTION_ID="${AZURE_SUBSCRIPTION_ID}"
  - AZURE_REGION="${AZURE_REGION}"
  - AZURE_INSTANCE_SIZE="Standard_DC2as_v5"
  - AZURE_RESOURCE_GROUP="${AZURE_RESOURCE_GROUP}"
  - AZURE_SUBNET_ID="${AZURE_SUBNET_ID}"
  - AZURE_IMAGE_ID="${AZURE_IMAGE_ID}"
secretGenerator:
- name: peer-pods-secret
  namespace: confidential-containers-system
- name: ssh-key-secret
  namespace: confidential-containers-system
  files:
  - id_rsa.pub
patchesStrategicMerge:
- workload-identity.yaml
EOF

The SSH public key should be accessible to the kustomization.yaml file:

cp $SSH_KEY install/overlays/azure/id_rsa.pub

Deploy CAA on the Kubernetes cluster

Run the following command to deploy CAA:

CLOUD_PROVIDER=azure make deploy

Generic CAA deployment instructions are also described here.

Run sample application

Ensure runtimeclass is present

Verify that the runtimeclass is created after deploying CAA:

kubectl get runtimeclass

Once you can find a runtimeclass named kata-remote then you can be sure that the deployment was successful. A successful deployment will look like this:

$ kubectl get runtimeclass
NAME          HANDLER       AGE
kata-remote   kata-remote   7m18s

Deploy workload

Create an nginx deployment:

echo '
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  namespace: default
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 1
  template:
    metadata:
      labels:
        app: nginx
    spec:
      runtimeClassName: kata-remote
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
        imagePullPolicy: Always
' | kubectl apply -f -

Ensure that the pod is up and running:

kubectl get pods -n default

You can verify that the peer pod VM was created by running the following command:

az vm list \
  --resource-group "${AZURE_RESOURCE_GROUP}" \
  --output table

Here you should see the VM associated with the pod nginx.

Note: If you run into problems then check the troubleshooting guide here.

Cleanup

If you wish to clean up the whole set up, you can delete the resource group by running the following command:

az group delete \
  --name "${AZURE_RESOURCE_GROUP}" \
  --yes --no-wait

1 - Advanced Azure Deployment Settings

This documentation has advanced settings for Azure deployment

Pod VM Images for Cloud API Adaptor (CAA)

Build a custom pod VM image

If you have made changes to the CAA code that affects the Pod-VM image and you want to deploy those changes then follow these instructions to build the pod-vm image.

Use nightly builds

An automated job builds the pod-vm image each night at 00:00 UTC. You can use that image by exporting the following environment variable:

SUCCESS_TIME=$(curl -s \
  -H "Accept: application/vnd.github+json" \
  "https://api.github.com/repos/confidential-containers/cloud-api-adaptor/actions/workflows/azure-podvm-image-nightly-build.yml/runs?status=success" \
  | jq -r '.workflow_runs[0].updated_at')

export AZURE_IMAGE_ID="/CommunityGalleries/cocopodvm-d0e4f35f-5530-4b9c-8596-112487cdea85/Images/podvm_image0/Versions/$(date -u -jf "%Y-%m-%dT%H:%M:%SZ" "$SUCCESS_TIME" "+%Y.%m.%d" 2>/dev/null || date -d "$SUCCESS_TIME" +%Y.%m.%d)"

Above image version is in the format YYYY.MM.DD, so to use the latest image use the date of yesterday.