Tutorial: Create an ARM template for a confidential container deployment with custom confidential computing enforcement policy
Confidential containers on ACI is a SKU on the serverless platform that enables customers to run container applications in a hardware-based and attested trusted execution environment (TEE), which can protect data in use and provides in-memory encryption via Secure Nested Paging.
In this article, you'll:
- Create an ARM template for a confidential container group
- Generate a confidential computing enforcement (CCE) policy
- Deploy the confidential container group to Azure
Before you begin
You must satisfy the following requirements to complete this tutorial:
Azure CLI: You must have Azure CLI version 2.44.1 or later installed on your local computer. Run
az --versionto find the version. If you need to install or upgrade, see Install the Azure CLI.Azure CLI confcom extension: You must have the Azure CLI confcom extension version 0.2.13+ installed to generate confidential computing enforcement policies.
Docker: This tutorial assumes a basic understanding of core Docker concepts like containers, container images, and basic docker commands. For a primer on Docker and container basics, see the Docker overview.
Docker: To complete this tutorial, you need Docker installed locally. Docker provides packages that configure the Docker environment on macOS, Windows, and Linux.
Azure CLI confcom extension: You must have the Azure CLI confcom extension version 0.30+ to generate confidential computing enforcement policies.
az extension add -n confcom
Important
Because the Azure Cloud shell does not include the Docker daemon, you must install both the Azure CLI and Docker Engine on your local computer to complete this tutorial. You cannot use the Azure Cloud Shell for this tutorial.
Create an ACI container group ARM Template
In this tutorial, you deploy a hello world application that generates a hardware attestation report. You start by creating an ARM template with a container group resource to define the properties of this application. You'll use this ARM template with the Azure CLI confcom tooling to generate a confidential computing enforcement (CCE) policy for attestation. In this tutorial, we use this ARM template. To view the source code for this application, visit ACI Confidential Hello World.
Note
The ccePolicy parameter of the template is blank and needs to be updated based on the next step of this tutorial.
There are two properties added to the Azure Container Instance resource definition to make the container group confidential:
- sku: The SKU property enables you to select between confidential and standard container group deployments. If this property isn't added, the container group will be deployed as standard SKU.
- confidentialComputeProperties: The confidentialComputeProperties object enables you to pass in a custom confidential computing enforcement policy for attestation of your container group. If this object isn't added to the resource there will be no validation of the software components running within the container group.
Use your preferred text editor to save this ARM template on your local machine as template.json.
You can see under confidentialComputeProperties, we have left a blank ccePolicy for you to fill in once you generate the policy in the next step.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"name": {
"type": "string",
"defaultValue": "helloworld",
"metadata": {
"description": "Name for the container group"
}
},
"location": {
"type": "string",
"defaultValue": "North Europe",
"metadata": {
"description": "Location for all resources."
}
},
"image": {
"type": "string",
"defaultValue": "mcr.microsoft.com/aci/aci-confidential-helloworld:v1",
"metadata": {
"description": "Container image to deploy. Should be of the form repoName/imagename:tag for images stored in public Docker Hub, or a fully qualified URI for other registries. Images from private registries require additional registry credentials."
}
},
"port": {
"type": "int",
"defaultValue": 80,
"metadata": {
"description": "Port to open on the container and the public IP address."
}
},
"cpuCores": {
"type": "int",
"defaultValue": 1,
"metadata": {
"description": "The number of CPU cores to allocate to the container."
}
},
"memoryInGb": {
"type": "int",
"defaultValue": 1,
"metadata": {
"description": "The amount of memory to allocate to the container in gigabytes."
}
},
"restartPolicy": {
"type": "string",
"defaultValue": "Never",
"allowedValues": [
"Always",
"Never",
"OnFailure"
],
"metadata": {
"description": "The behavior of Azure runtime if container has stopped."
}
}
},
"resources": [
{
"type": "Microsoft.ContainerInstance/containerGroups",
"apiVersion": "2023-05-01",
"name": "[parameters('name')]",
"location": "[parameters('location')]",
"properties": {
"confidentialComputeProperties": {
"ccePolicy": ""
},
"containers": [
{
"name": "[parameters('name')]",
"properties": {
"image": "[parameters('image')]",
"ports": [
{
"port": "[parameters('port')]",
"protocol": "TCP"
}
],
"resources": {
"requests": {
"cpu": "[parameters('cpuCores')]",
"memoryInGB": "[parameters('memoryInGb')]"
}
}
}
}
],
"sku": "Confidential",
"osType": "Linux",
"restartPolicy": "[parameters('restartPolicy')]",
"ipAddress": {
"type": "Public",
"ports": [
{
"port": "[parameters('port')]",
"protocol": "TCP"
}
]
}
}
}
],
"outputs": {
"containerIPv4Address": {
"type": "string",
"value": "[reference(resourceId('Microsoft.ContainerInstance/containerGroups', parameters('name'))).ipAddress.ip]"
}
}
}
Create a custom CCE Policy
With the ARM template that you've crafted and the Azure CLI confcom extension, you're able to generate a custom CCE policy. the CCE policy is used for attestation. The tool takes the ARM template as an input to generate the policy. The policy enforces the specific container images, environment variables, mounts, and commands, which can then be validated when the container group starts up. For more information on the Azure CLI confcom extension, see Azure CLI confcom extension.
To generate the CCE policy, you'll run the following command using the ARM template as input:
az confcom acipolicygen -a .\template.json --print-policyWhen this command completes, you should see a Base 64 string generated as output in the format seen below. This string is the CCE policy that you will copy and paste into your ARM template under the ccePolicy property.
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 the changes to your local copy of the ARM template.
Deploy the template
Select the following Deploy to Azure button to sign in to Azure and begin an Azure Container Instances deployment.
Choose Build your own template in the editor. You'll see a mostly blank template JSON.
Select Load file and upload template.json, which you've modified by adding the CCE policy you generated in the previous steps.
Click Save.
Select or enter the following values.
- Subscription: select an Azure subscription.
- Resource group: select Create new, enter a unique name for the resource group, and then select OK.
- Location: select a location for the resource group. Choose a region where the Confidential SKU is supported. Example: North Europe.
- Name: accept the generated name for the instance, or enter a name.
- Image: accept the default image name. This sample Linux image displays a hardware attestation.
Accept default values for the remaining properties.
Review the terms and conditions. If you agree, select I agree to the terms and conditions stated above.
After the instance has been created successfully, you get a notification:
The Azure portal is used to deploy the template. In addition to the Azure portal, you can use the Azure PowerShell, Azure CLI, and REST API. To learn other deployment methods, see Deploy templates.
Review deployed resources
Use the Azure portal or a tool such as the Azure CLI to review the properties of the container instance.
In the portal, search for Container Instances, and select the container instance you created.
On the Overview page, note the Status of the instance and its IP address.
Once its status is Running, navigate to the IP address in your browser.
The presence of the attestation report below the Azure Container Instances logo confirms that the container is running on hardware that supports a TEE. If you deploy to hardware that does not support a TEE, for example by choosing a region where the ACI Confidential SKU is not available, no attestation report will be shown.
Next Steps
Now that you have deployed a confidential container group on ACI, you can learn more about how policies are enforced.
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