Akka Management

Azure API

Project Info

Discovery Method: AKS Azure RBAC Based Discovery

You can use azure-rbac-aks-api based discovery with azure rbac and workload identity enabled AKS clusters.

The Akka dependencies are available from Akka’s library repository. To access them there, you need to configure the URL for this repository.

sbt

resolvers += "Akka library repository".at("https://repo.akka.io/maven")

Gradle

repositories {
    mavenCentral()
    maven {
        url "https://repo.akka.io/maven"
    }
}

Maven

<project>
  ...
  <repositories>
    <repository>
      <id>akka-repository</id>
      <name>Akka library repository</name>
      <url>https://repo.akka.io/maven</url>
    </repository>
  </repositories>
</project>

Additionally, add the dependency as below.

sbt

val AkkaManagementVersion = "1.6.0"
libraryDependencies += "com.lightbend.akka.discovery" %% "akka-discovery-azure-api" % AkkaManagementVersion

Gradle

def versions = [
  AkkaManagementVersion: "1.6.0",
  ScalaBinary: "2.13"
]
dependencies {
  implementation "com.lightbend.akka.discovery:akka-discovery-azure-api_${versions.ScalaBinary}:${versions.AkkaManagementVersion}"
}

Maven

<properties>
  <akka.management.version>1.6.0</akka.management.version>
  <scala.binary.version>2.13</scala.binary.version>
</properties>
<dependencies>
  <dependency>
    <groupId>com.lightbend.akka.discovery</groupId>
    <artifactId>akka-discovery-azure-api_${scala.binary.version}</artifactId>
    <version>${akka.management.version}</version>
  </dependency>
</dependencies>

Getting started

akka-discovery-azure-api is similar to the akka-discovery-kubernetes-api in that it queries the AKS Kubernetes API server to find pods with a given label but different in terms how authentication and authorization work. The discovery method doesn’t require using the more traditional Kubernetes RBAC but instead relies on using Azure RBAC.

• Authentication and Authorization is set to Microsoft Entra ID authentication with Azure RBAC

• Workload Identity is enabled for the AKS cluster

az aks update --resource-group "${RESOURCE_GROUP}" \
  --name "${CLUSTER_NAME}" --enable-oidc-issuer \
  --enable-workload-identity

• Create a Microsoft Azure Manged Identity

az identity create --name "${USER_ASSIGNED_IDENTITY_NAME}" \
  --resource-group "${RESOURCE_GROUP}" --location "${LOCATION}" \
  --subscription "${SUBSCRIPTION}"

• Assign AKS Pod Reader to the Managed Identity

• Create Federated Credential for the Managed Identity

az identity federated-credential create \
  --name ${FEDERATED_IDENTITY_CREDENTIAL_NAME} \
  --identity-name "${USER_ASSIGNED_IDENTITY_NAME}" \
  --resource-group "${RESOURCE_GROUP}" --issuer "${AKS_OIDC_ISSUER}" \
  --subject system:serviceaccount:"${SERVICE_ACCOUNT_NAMESPACE}":"${SERVICE_ACCOUNT_NAME}" \
  --audience api://AzureADTokenExchange

• Create a Kubernetes Service Account

kubectl apply -f - <<EOF
apiVersion: v1
kind: ServiceAccount
metadata:
  name: <akka-app>
  namespace: <akka-app-namespace>
  annotations:
    azure.workload.identity/client-id: "XXXXXXXXXXXXXXXXX"
EOF

• Label Pods with azure.workload.identity/use: "true"

kubectl apply -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  name: <akka-app>
  namespace: <akka-app-namespace>
# Removed for brevity
spec:
  template:
    metadata:
      labels:
        azure.workload.identity/use: "true"
     spec:
      serviceAccountName: <akka-app>
      # Removed for brevity

• Change application.conf to use the discovery method:

akka {
  # Removed for brevity
  management {
    cluster.bootstrap {
      contact-point-discovery {
        discovery-method = azure-rbac-aks-api
        azure-rbac-aks-api {
          pod-namespace = "test-akka-app"
        }
      }
    }
  }
}

Azure’s workload identity controller will inject your application pods with environment variables that the discovery method uses to query the AKS Kubernetes Cluster’s API Server. Here’s a list of environment variables that get injected in pods:

${AZURE_AUTHORITY_HOST}
${AZURE_AUTHORITY_HOST}
${AZURE_AUTHORITY_HOST}
${AZURE_AUTHORITY_HOST}

Additionally, the discovery method uses the AZURE_SERVER_ID environment variable whose default value is set to 6dae42f8-4368-4678-94ff-3960e28e3630/.default. This is the application used by the server side. The access token accessing AKS clusters need to be issued for this app.