The Microsoft Azure cloud and Juju

List of supported clouds > Microsoft Azure

This document describes details specific to using your existing Microsoft Azure cloud with Juju.

See more: Microsoft Azure

When using the Microsoft Azure cloud with Juju, it is important to keep in mind that it is a (1) machine cloud and (2) not some other cloud.

See more: Cloud differences in Juju

As the differences related to (1) are already documented generically in our Tutorial, How-to guides, and Reference docs, here we record just those that follow from (2).

Requirements

If you’re in a locked-down environment:
Permissions:

- Microsoft.Compute/skus (read)

- Microsoft.Resources/subscriptions/resourceGroups (read, write, delete)

- Microsoft.Resources/deployments/ (write/read/delete/cancel/validate)

- Microsoft.Network/networkSecurityGroups (write, read, delete, other - join)

- Microsoft.Network/virtualNetworks/ (write, read, delete)

- Microsoft.Compute/virtualMachineScaleSets/ (write, read, delete, other - start action, other - deallocate action, other - restart action, other powerOff action)

- Microsoft.Network/virtualNetworks/subnets/ (read, write, delete, other - join)

- Microsoft.Compute/availabilitySets (write, read, delete)

- Microsoft.Network/publicIPAddresses (write, read, delete, other - join - optional for public services)

- Microsoft.Network/networkInterfaces (write, read, delete, other - join)

- Microsoft.Compute/virtualMachines (write, read, delete, other - start, power off, restart, deallocate)

- Microsoft.Compute/disks (write, read, delete)

Notes on juju add-cloud

Type in Juju: azure.

Name in Juju: azure.

Notes on juju add-credential

Authentication types

managed-identity (preferred)

Requirements:

• Juju 3.6+.
• A managed identity. See more: Appendix: How to create a managed identity.
• The managed identity and the Juju resources must be created on the same subscription.
• The add-credential steps must be run from either the Azure Cloud Shell^ or a jump host running in Azure in order to allow the cloud metadata endpoint to be reached.

This is the recommended way to authenticate with Azure as this way you are never touching your cloud credentials directly.

See more: Appendix: Example authentication workflows > Workflow 1

interactive = “service-principal-secret-via-browser”

This is the recommended way to authenticate with Azure if you want to use a service principal secret.

When you add the credential in this way and provide the subscription ID, Juju will open up a browser and you’ll be prompted to log in to Azure.

If you are using the unconfined juju snap /snap/juju/current/bin/juju add-credential azure and have the azure CLI and you are logged in and you want to use the currently logged in user: You may leave the subscription ID empty – Juju will fill it in for you.

If you decide to fill in the optional fields as well: Make sure to set them to unique values (i.e., the application-name and role-definition-name fields cannot be the same).

Starting with Juju 3.6, you can also combine this authentication type with a managed identity by bootstrapping with the instance-role constraint.

See more: Appendix: Example authentication workflows > Workflows 2-3

service-principal-secret (dispreferred)

Starting with Juju 3.6, you can also combine this with a managed identity by bootstrapping with the instance-role constraint.

See more: Appendix: Example authentication workflows > Workflows 2-3

Notes on juju bootstrap

If during juju add-credential you chose interactive (= “service-principal-secret-via-browser”) or service-principal-secret: You can still combine this with a managed identity by running juju bootstrap with --constraints instance-role=....

See more: Appendix: Example authentication workflows > Workflow 2, Supported constraints

Cloud-specific model configuration keys

load-balancer-sku-name

Mirrors the LoadBalancerSkuName type in the Azure SDK.

resource-group-name

If set, use the specified resource group for all model artefacts instead of creating one based on the model UUID.

network

If set, use the specified virtual network for all model machines instead of creating one.

Supported constraints

Supported placement directives

Appendix: Example authentication workflows

Worflow 1 – Managed identity only (recommended)

Requirements:

• Juju 3.6+.
• A managed identity. See more: Appendix: How to create a managed identity.
• The managed identity and the Juju resources must be created on the same subscription.
• The add-credential steps must be run from either the Azure Cloud Shell^ or a jump host running in Azure in order to allow the cloud metadata endpoint to be reached.

1. Create a managed identity. See more: Appendix: How to create a managed identity.
2. Run juju add-credential azure; choose managed-identity; supply the requested information (the“managed-identity-path” must be of the form <resourcegroup>/<identityname>).
3. Bootstrap as usual.

Workflow 2 – Service principal secret + managed identity

Requirements:

• Juju 3.6+.
• A managed identity. See more: Appendix: How to create a managed identity.

1. Create a managed identity.
2. Add a service-principal-secret:
   • interactive = “service-principal-via-browser” (recommended):
     • If you have the azure CLI and you are logged in and you want to use the currently logged in user: Run /snap/juju/current/bin/juju add-credential azure; choose interactive, then leave the subscription ID field empty – Juju will fill this in for you.
     • Otherwise: Run juju add-credential azure, choose interactive, then provide the subscription ID – Juju will open up a browser and you’ll be prompted to log in to Azure.
   • service-principal-secret: Run juju add-credential azure, then choose service-principal-secret and supply all the requested information.
3. During bootstrap, provide the managed identity to the controller by using the instance-role constraint.

Workflow 3 – Service principal secret only (dispreferred)

1. Add a service-principal-secret:
   • interactive = “service-principal-via-browser” (recommended):
     • If you have the azure CLI and you are logged in and you want to use the currently logged in user: Run /snap/juju/current/bin/juju add-credential azure; choose interactive, then leave the subscription ID field empty – Juju will fill this in for you.
     • Otherwise: Run juju add-credential azure, choose interactive, then provide the subscription ID – Juju will open up a browser and you’ll be prompted to log in to Azure.
   • service-principal-secret: Run juju add-credential azure, then choose service-principal-secret and supply all the requested information.
2. Bootstrap as usual.

Appendix: How to create a managed identity

To create a managed identity for Juju to use, you will need to use the Azure CLI and be logged in to your account. This is a set up step that can be done ahead of time by an administrator.

The 4 values below need to be filled in according to your requirements.

$ export group=someresourcegroup
$ export location=someregion
$ export role=myrolename
$ export identityname=myidentity
$ export subscription=mysubscription_id

The role definition and role assignment can be scoped to either the subscription or a particular resource group. If scoped to a resource group, this group needs to be provided to Juju when bootstrapping so that the controller resources are also created in that group.

For a subscription scoped managed identity:

$ az group create --name "${group}" --location "${location}"
$ az identity create --resource-group "${group}" --name "${identityname}"
$ mid=$(az identity show --resource-group "${group}" --name "${identityname}" --query principalId --output tsv)
$ az role definition create --role-definition "{
  	\"Name\": \"${role}\",
  	\"Description\": \"Role definition for a Juju controller\",
  	\"Actions\": [
            	\"Microsoft.Compute/*\",
            	\"Microsoft.KeyVault/*\",
            	\"Microsoft.Network/*\",
            	\"Microsoft.Resources/*\",
            	\"Microsoft.Storage/*\",
            	\"Microsoft.ManagedIdentity/userAssignedIdentities/*\"
  	],
  	\"AssignableScopes\": [
        	\"/subscriptions/${subscription}\"
  	]
  }"
$ az role assignment create --assignee-object-id "${mid}" --assignee-principal-type "ServicePrincipal" --role "${role}" --scope "/subscriptions/${subscription}"

A resource scoped managed identity is similar except:

• the role definition assignable scopes becomes

      \"AssignableScopes\": [
            \"/subscriptions/${subscription}/resourcegroups/${group}\"
      ]

• the role assignment scope becomes

--scope "/subscriptions/${subscription}/resourcegroups/${group}"

Contributors: @kylerhornor , @taurus , @tmihoc, @wallyworld