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Set up VPC peering on Azure

Create an isolated Microsoft Azure virtual network in your Aiven deployment where you can create services instead of using Aiven Cloud's public network.

See the Using VPC peering for how to set up a Project VPC.

note
  • Azure uses the term Virtual Network (VNet), which is the same as a Virtual Private Cloud (VPC). We use the terms interchangeably.

Peer your network with the VPC​

For an Azure virtual network peering's state to become connected between networks A and B, a peering must be created both from network A to B and from B to A. See Create a virtual network peering for an overview.

In the case of Project VPCs, one of the networks is located in the Aiven subscription and the Aiven platform handles creating the peering from that network to the network you wish to peer. For this the Aiven platform's Active Directory application object needs permissions in your subscription. Because the peering is between subscriptions with different AD tenants, an application object is also needed to your AD tenant, which can be used to create the peering from your network to Aiven once it's been given permissions to do so.

Preparation​

Install:

1. log in with an Azure admin account​

Using the Azure CLI:

az account clear
az login

This should open a window in your browser prompting to choose an Azure account to log in with. An account with at least the Application administrator role assignment will be needed for the later steps.

If you manage multiple Azure subscriptions, also configure the Azure CLI to default to the correct subscription for the subsequent commands. This is not needed if there's only one subscription:

az account set --subscription <subscription name or id>

2. create application object​

Create an application object in your AD tenant. Using the Azure CLI, this can be done with:

az ad app create --display-name "<name of your choosing>" --sign-in-audience AzureADMultipleOrgs --key-type Password

This creates an entity to your AD that can be used to log into multiple AD tenants ( --sign-in-audience AzureADMultipleOrgs ), but only the home tenant (the tenant the app was created in) has the credentials to authenticate the app. Save the appId field from the output - this will be referred to as $user_app_id

3. create a service principal for your app object​

Create a service principal for the app object you created. The service principal should be created to the Azure subscription the VNet you wish to peer is located in:

az ad sp create --id $user_app_id

This creates a service principal to your subscription that may given permissions to peer your VNet. Save the id field from the JSON output - this will be referred to as $user_sp_id. Notice that this is different from the $user_app_id value earlier, which is also shown in the output.

4. set a password for your app object​

az ad app credential reset --id $user_app_id

Save the password field from the output - this will be referred to as $user_app_secret below

5. find the id properties of your virtual network​

This can be found in the Azure portal in Virtual networks > name of your network > JSON View > Resource ID, or using

az network vnet list

Save the id field which will be referred to as $user_vnet_id. Also grab

  • the Azure Subscription ID (Properties > Subscription ID) or the part after /subscriptions/ in the resource ID. This is referred to as $user_subscription_id
  • the resource group name (Properties > Resource group) or the resourceGroup field in the output. This is referred to as $user_resource_group
  • the VNet name (title of the network page), or the name field from the output. Save this for later as $user_vnet_name

$user_vnet_id should have the format /subscriptions/$user_subscription_id/ resourceGroups/$user_resource_group/providers/Microsoft.Network/virtualNetworks/$user_vnet_name

6. grant your service principal permissions to peer​

The service principal created in step 3 needs to be assigned a role that has permission for the Microsoft.Network/virtualNetworks/virtualNetworkPeerings/write action on the scope of your VNet. To limit the amount of permissions the app object and service principal has, you can create a custom role with just that permission. The built-in Network Contributor role includes that permission, and can be found using the Azure CLI with

az role definition list --name "Network Contributor"

The id field from the output will be used as $network_contributor_role_id to assign the service principal that role:

az role assignment create --role $network_contributor_role_id --assignee-object-id $user_sp_id --scope $user_vnet_id

This allows the application object created earlier to manage the network in the --scope above. Since the application object is controlled by you, it may also be given permission for the scope of an entire resource group, or the whole subscription to allow create other peerings later without assigning the role again for each VNet separately.

7. create a service principal for the Aiven application object​

The Aiven AD tenant contains an application object (similar to the one you created in step 2 that the Aiven platform uses to create a peering from the Project VPC VNet in the Aiven subscription to the VNet from step 5 in your subscription. For this the Aiven app object needs a service principal in your subscription:

az ad sp create --id 55f300d4-fc50-4c5e-9222-e90a6e2187fb

The argument to --id field above is the ID of the Aiven application object, this is a fix id and the command must be run like that. Save the id field from the JSON output - (just above the info field) - it will be referred to as $aiven_sp_id later.

If this fails with the error "When using this permission, the backing application of the service principal being created must in the local tenant" then your account does not have the correct permissions. Use an account with at least the Application administrator role assigned.

8. create a custom role for the Aiven application object​

The Aiven application now has a service principal that can be given permissions. In order to target a network in your subscription with a peering and nothing else, we'll create a this a custom role definition, with only a single action allowing to do that and only that:

az role definition create --role-definition '{"Name": "<name of your choosing>", "Description": "Allows creating a peering to vnets in scope (but not from)", "Actions": ["Microsoft.Network/virtualNetworks/peer/action"], "AssignableScopes": ["/subscriptions/'$user_subscription_id'"]}'

Creating a custom role must include your subscription's id in AssignableScopes. This in itself does not give permissions to your subscription. It restricts which scopes a role assignment can include. Save the id field from the output - this will be referred to as $aiven_role_id

9. assign the custom role to the Aiven service principal​

To give the Aiven application object's service principal permissions to peer with your VNet, assign the role created in the previous step to the Aiven service principal (step 7) with the scope of your VNet (step 5) with

az role assignment create --role $aiven_role_id --assignee-object-id $aiven_sp_id --scope $user_vnet_id

10. find your AD tenant id​

The ID of your AD tenant will be needed in the next step. Find it from the Azure portal from Azure Active Directory > Properties > Directory ID or with the Azure CLI using

az account list

saving the tenantId field from the output. It will be referred to as $user_tenant_id later

11. create a peering connection from the Aiven Project VPC​

This leads to the Aiven platform creating a peering from the VNet in the Aiven Project VPC to the VNet in your subscription. In addition it will create a service principal for the application object in your tenant ( --peer-azure-app-id $user_app_id ) giving it permission to target the Aiven subscription VNet with a peering. Your AD tenant ID is also needed in order for the Aiven application object to authenticate with your tenant to give it access to the service principal created in step 7 ( --peer-azure-tenant-id $user_tenant_id ).

$aiven_project_vpc_id is the ID of the Aiven Project VPC, and can be found with avn vpc list

Using the Aiven CLI:

avn vpc peering-connection create --project-vpc-id $aiven_project_vpc_id --peer-cloud-account $user_subscription_id --peer-resource-group $user_resource_group --peer-vpc $user_vnet_name --peer-azure-app-id $user_app_id --peer-azure-tenant-id $user_tenant_id

Note that the arguments starting with $user_ should be given in lower case. Azure resource names are case-agnostic, but the Aiven API currently only accepts names in lower case. If no error is shown, the peering connection is being set up by the Aiven platform.

12. wait for the Aiven platform to set up the connection​

Run the following command until the state is no longer APPROVED, but PENDING_PEER :

avn vpc peering-connection get -v --project-vpc-id $aiven_project_vpc_id --peer-cloud-account $user_subscription_id --peer-resource-group $user_resource_group --peer-vpc $user_vnet_name

A state such as INVALID_SPECIFICATION or REJECTED_BY_PEER may be shown if the VNet specified in the previous step did not exist, or the Aiven app object wasn't given permissions to peer with it. If that occurs, check your configuration and recreate the peering connection in step 12.

If everything went as expected, the state changes to PENDING_PEER within a couple of minutes showing details to set up the peering connection from your VNet to the Project VPC's VNet in the Aiven subscription.

Save the to-tenant-id field from the output. It will be referred to as the aiven_tenant_id later. The to-network-id field from the output is referred to as the $aiven_vnet_id

13. create peering from your VNet to the VNet of the project VPC​

Log out the Azure user you logged in with in step 1 using

az account clear

Log in the application object you created in step 2 to your AD tenant using the password you created in step 4:

az login --service-principal -u $user_app_id -p $user_app_secret --tenant $user_tenant_id

Log in the same application object to the Aiven AD tenant:

az login --service-principal -u $user_app_id -p $user_app_secret --tenant $aiven_tenant_id

Now that your application object has a session with both AD tenants, create a peering from your VNet to the VNet in the Aiven subscription with

az network vnet peering create --name <peering name of your choosing> --remote-vnet $aiven_vnet_id --vnet-name $user_vnet_name --resource-group $user_resource_group --subscription $user_subscription_id --allow-vnet-access

Note that without --allow-vnet-access no traffic is allowed to flow from the peered VNet and Aiven services cannot be reached through the peering. After the peering has been created the peering should be in state connected

In case you get the error below, it's possible the role assignment from step 6 hasn't taken effect yet. If that is the case, try logging in again and creating the peering again after waiting a bit by repeating the commands in this step. If the error message persists, check the role assignment in step 6 was correct.

The client '<random uuid>' with object id '<another random uuid>' does not have authorization to perform action 'Microsoft.Network/virtualNetworks/virtualNetworkPeerings/write' over scope '$user_vnet_id' If access was recently granted, refresh your credentials.

14. wait until the Aiven peering connection is active​

The Aiven platform polls peering connections in state PENDING_PEER regularly to see if the peer (your subscription) has created a peering connection to the Aiven Project VPC's VNet. Once this is detected, the state changes from PENDING_PEER to ACTIVE. After this services in the Project VPC can be reached through the peering. To check if the peering connection is ACTIVE, run the same Aiven CLI avn vpc peering-connection get command from step 12. In some cases it has taken up to 15 minutes for the state to update:

avn vpc peering-connection get -v --project-vpc-id $aiven_project_vpc_id --peer-cloud-account $user_subscription_id --peer-resource-group $user_resource_group --peer-vpc $user_vnet_name