Azure LinkedAuthorizationFailed Error: Diagnose and Resolve Connection Issues

Table of Contents

The LinkedAuthorizationFailed error in Microsoft Azure can be a significant roadblock when deploying and managing Azure Kubernetes Service (AKS) clusters. This error typically arises during the cluster creation process and indicates an authorization problem related to linked resources. Understanding the root cause and implementing the correct solution is crucial to ensure successful AKS deployments and maintain smooth operations. This article provides a comprehensive guide to diagnosing and resolving the LinkedAuthorizationFailed error, enabling you to overcome connection issues and proceed with your AKS cluster setup.

Symptoms¶

When attempting to create an AKS cluster, you might encounter a failure accompanied by the following error message. This message is usually displayed within the Azure portal, Azure CLI, or other tools used for AKS deployment:

Reconcile VNet failed.

Details: VNetReconciler retry failed:

Category: ClientError; SubCode: LinkedAuthorizationFailed;

Dependency: Microsoft.Network/virtualNetworks; OrginalError: Code=”LinkedAuthorizationFailed”

Message=”The client ‘12345678-1234-1234-1234-123456789098’ with object id ‘123456789-1234-1234-1234-1234567890987’ has permission to perform action ‘Microsoft.Network/virtualNetworks/write’ on scope ‘/subscriptions//resourceGroups/MC_MyRG_westeurope/providers/Microsoft.Network/virtualNetworks/aks-vnet’; however, it does not have permission to perform action ‘Microsoft.Network/ddosProtectionPlans/join/action’ on the linked scope(s) ‘/subscriptions//resourcegroups/ddos-protection-plan-rg/providers/microsoft.network/ddosprotectionplans/upmddosprotectionplan’ or the linked scope(s) are invalid.”;

AKSTeam: Networking, Retriable: false.

This error message, while seemingly complex, provides valuable clues about the underlying problem. Let’s break down the key components of this message to understand what it signifies:

• Reconcile VNet failed: This indicates that the error is occurring during the process of setting up or configuring the Virtual Network (VNet) for your AKS cluster. VNets are fundamental networking components in Azure, and AKS clusters rely on them for network isolation and connectivity.
• Category: ClientError; SubCode: LinkedAuthorizationFailed;: This clearly points to a client-side authorization issue. The LinkedAuthorizationFailed subcode specifically tells us that the problem is related to permissions on a linked resource.
• Dependency: Microsoft.Network/virtualNetworks;: This specifies that the dependency causing the error is related to Azure Virtual Networks. AKS needs to interact with VNets to create and manage network resources for the cluster.
• OrginalError: Code=”LinkedAuthorizationFailed”: This reiterates the error code, confirming the type of issue.
• Message=”… “ : This is the most informative part of the error message. It details:
  • The client: Identifies the service principal (client ID and object ID) that is attempting to perform the action. Service principals are security identities used by applications, services, and automation tools to access Azure resources.
  • Permission Granted: States that the service principal does have permission to perform 'Microsoft.Network/virtualNetworks/write' on the VNet scope. This might seem confusing, but it highlights that the basic VNet write permission is not the problem.
  • Permission Denied: Crucially, it states that the service principal does not have permission to perform 'Microsoft.Network/ddosProtectionPlans/join/action' on the linked scope. This is the core of the problem.
  • Linked Scope(s): Specifies the linked scope where the permission is missing: '/subscriptions/<subscription-id-guid>/resourcegroups/ddos-protection-plan-rg/providers/microsoft.network/ddosprotectionplans/upmddosprotectionplan'. This points to an Azure DDoS Protection Plan resource.

In essence, the error message is telling us that while the service principal has permissions to work with the AKS cluster’s VNet itself, it lacks the necessary permission to interact with a linked resource, in this case, a DDoS Protection Plan. This lack of permission is preventing the AKS cluster creation process from completing successfully.

Cause¶

The root cause of the LinkedAuthorizationFailed error is almost always related to insufficient permissions for a service principal. Specifically, the service principal used by AKS to manage resources in your Azure subscription does not have the required permissions to access or utilize a linked Azure resource necessary for cluster creation.

To understand this better, let’s consider the role of service principals in Azure and how AKS operates.

When you create an AKS cluster, Azure automatically manages many underlying resources on your behalf. This management is performed by an Azure-managed service principal associated with your AKS cluster. This service principal needs specific permissions within your subscription to create, modify, and manage resources like:

• Virtual Machines (for the AKS nodes)
• Load Balancers
• Network Interfaces
• Storage Accounts
• Virtual Networks
• And potentially, linked services like DDoS Protection Plans, Container Registries, etc.

The LinkedAuthorizationFailed error arises when, during the AKS cluster creation or operation, AKS attempts to interact with one of these linked resources, and its service principal lacks the necessary permissions to do so.

In the specific error message example, the linked resource is a DDoS Protection Plan. Azure DDoS Protection provides enhanced DDoS mitigation capabilities for your Azure resources. If your AKS cluster deployment or configuration is attempting to integrate with or join an existing DDoS Protection Plan, the AKS service principal must have the 'Microsoft.Network/ddosProtectionPlans/join/action' permission on that DDoS Protection Plan resource.

If this permission is missing, the LinkedAuthorizationFailed error will occur, blocking the AKS cluster creation or operation. This situation can arise for several reasons:

1. Insufficient Default Permissions: The default permissions granted to the AKS service principal might not automatically include access to all possible linked resources. Permissions are typically granted based on the specific actions required during the core AKS cluster lifecycle. Access to optional linked services may require explicit permission grants.
2. Custom Role Assignments: If you are using custom Azure roles for managing permissions instead of built-in roles, it’s possible that the custom role assigned to the AKS service principal is missing the required permissions for the linked resource. Carefully review the permissions defined in your custom roles.
3. Resource Group Scope: Permissions in Azure RBAC (Role-Based Access Control) are granted at a specific scope (e.g., subscription, resource group, or individual resource). If the required permission is granted at a scope that is too narrow (e.g., only on the AKS cluster’s resource group, but not on the resource group containing the DDoS Protection Plan), the error can occur. The service principal needs permission on the scope where the linked resource resides.
4. Accidental Permission Revocation: In some cases, permissions that were previously granted to the AKS service principal might have been accidentally revoked or modified, leading to the error. Audit logs can help in investigating such scenarios.

Essentially, the LinkedAuthorizationFailed error is a clear indicator of a permissions gap. The AKS service principal, acting on your behalf, is being told “Access Denied” when it tries to perform an action on a linked resource because it hasn’t been explicitly granted the necessary authorization.

Solution¶

Resolving the LinkedAuthorizationFailed error involves granting the AKS service principal the necessary permissions to access the linked resource mentioned in the error message. The error message itself provides all the key information needed to implement the solution. Let’s revisit the example error message:

Message=”The client ‘12345678-1234-1234-1234-123456789098’ … does not have permission to perform action ‘Microsoft.Network/ddosProtectionPlans/join/action’ on the linked scope(s) ‘/subscriptions//resourcegroups/ddos-protection-plan-rg/providers/microsoft.network/ddosprotectionplans/upmddosprotectionplan’“

From this message, we can extract the following crucial details:

Item	Value
Service Principal	12345678-1234-1234-1234-123456789098
Resource	/subscriptions/<subscription-id-guid>/resourcegroups/ddos-protection-plan-rg/providers/microsoft.network/ddosprotectionplans/upmddosprotectionplan
Operation	Microsoft.Network/ddosProtectionPlans/join/action

To resolve the error, you need to grant the specified service principal ( 12345678-1234-1234-1234-123456789098 ) the permission to perform the operation (Microsoft.Network/ddosProtectionPlans/join/action) on the identified resource (/subscriptions/<subscription-id-guid>/resourcegroups/ddos-protection-plan-rg/providers/microsoft.network/ddosprotectionplans/upmddosprotectionplan).

Here’s a step-by-step guide on how to grant these permissions using the Azure portal. While the original article may link to specific documentation, we will describe the general process:

1. Identify the Service Principal: Locate the service principal ID from the error message. In our example, it’s 12345678-1234-1234-1234-123456789098. You might need to search for this service principal within your Azure Active Directory. Sometimes, AKS managed service principals are named in a way that relates to the AKS cluster itself.
2. Navigate to the Linked Resource: In the Azure portal, go to the resource group that contains the linked resource. In our example, this is the resource group ddos-protection-plan-rg. Then, find the specific DDoS Protection Plan resource named upmddosprotectionplan.
3. Access Control (IAM): Within the DDoS Protection Plan resource blade, navigate to Access control (IAM). This is where you manage role assignments for Azure resources.
4. Add Role Assignment: Click on + Add and then Add role assignment.
5. Select Role: Choose a suitable built-in Azure role that includes the required permission Microsoft.Network/ddosProtectionPlans/join/action. The Network Contributor role is often a good choice as it provides broad network management permissions, including the ability to join DDoS Protection Plans. However, for a more least-privilege approach, you could consider creating a custom role that specifically includes only the Microsoft.Network/ddosProtectionPlans/join/action permission and any other truly necessary permissions.
6. Assign access to: Select Service principal.
7. Select Members: In the “Select members” pane, search for the service principal ID you identified in step 1 (12345678-1234-1234-1234-123456789098). Select the correct service principal from the search results.
8. Review and Assign: Review your role assignment details (role, service principal, scope - which is the DDoS Protection Plan resource in this case) and click Review + assign to create the role assignment.

After granting the necessary permissions, retry the AKS cluster creation or operation that was failing. In most cases, the LinkedAuthorizationFailed error should be resolved, and the process should complete successfully.

Alternative Methods for Granting Permissions:

While the Azure portal is a common way to manage RBAC, you can also use other tools:

• Azure CLI: Use the az role assignment create command to grant roles to service principals via the command line. This is useful for automation and scripting.
• Azure PowerShell: Utilize the New-AzRoleAssignment cmdlet to achieve the same result using PowerShell.
• ARM Templates or Bicep: For infrastructure-as-code deployments, you can include role assignments directly within your ARM templates or Bicep files to ensure permissions are configured as part of your deployment process.

Important Considerations:

• Least Privilege: While granting broad roles like “Network Contributor” might quickly resolve the issue, it’s generally recommended to adhere to the principle of least privilege. Ideally, create custom roles with only the essential permissions needed for the AKS service principal to function correctly. This enhances security by limiting the potential impact if the service principal is ever compromised.
• Scope of Permissions: Carefully consider the scope at which you are granting permissions. Granting permissions at a resource group or subscription level might be necessary in some cases, but granting them at the specific resource level (like the DDoS Protection Plan) is often more secure and aligned with least privilege.
• Propagation Time: Azure RBAC changes might take a few minutes to propagate throughout the system. If you retry the AKS operation immediately after granting permissions and still see the error, wait a short period and try again.

By understanding the cause of the LinkedAuthorizationFailed error and following the steps to grant the appropriate permissions to the AKS service principal, you can effectively resolve this issue and ensure successful AKS cluster deployments and operations in Azure.

More Information¶

For further information and related troubleshooting guidance, consider exploring these topics:

• General troubleshooting of AKS cluster creation issues: Familiarize yourself with common issues that can arise during AKS cluster creation and general troubleshooting techniques.
• Azure Role-Based Access Control (RBAC): Deepen your understanding of Azure RBAC, roles, role assignments, and how permissions are managed in Azure. Understanding RBAC is fundamental for managing security and access control in Azure environments.
• Azure DDoS Protection: Learn more about Azure DDoS Protection and how it can enhance the security and resilience of your Azure resources, including AKS clusters. If you are encountering this error related to DDoS Protection, understanding the service itself is beneficial.
• AKS Security Best Practices: Explore security best practices for AKS, including service principal management, network security, and overall cluster hardening.

By proactively managing permissions and understanding the dependencies of AKS clusters, you can minimize the occurrence of authorization-related errors like LinkedAuthorizationFailed and maintain a secure and smoothly operating Azure environment.

If you continue to experience issues or have further questions about resolving LinkedAuthorizationFailed errors in AKS, consider reaching out to Azure support or consulting the official Azure documentation for more in-depth assistance.

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We hope this article has provided a clear understanding of the LinkedAuthorizationFailed error and equipped you with the knowledge to diagnose and resolve it effectively. Do you have any experiences with this error or further questions? Share your thoughts and comments below!