Kubernetes: How do I tell what GCP service account my service is running as?

In the dynamic landscape of cloud computing, Kubernetes has emerged as a powerful container orchestration platform, allowing developers to deploy and manage applications seamlessly. When working within the Google Cloud Platform (GCP) environment, it's essential to understand the service account associated with your Kubernetes service. This knowledge is crucial for maintaining security, managing permissions, and troubleshooting potential issues. In this article, we will explore the steps to determine the GCP service account that your Kubernetes service is running as.

Identifying the GCP Service Account: Commands and Steps

Step 1: Accessing the Kubernetes Cluster

Before diving into identifying the service account, make sure you have access to your Kubernetes cluster. You can use the following command to access your cluster:

kubectl config use-context [your-cluster-name]

Replace [your-cluster-name] with the actual name of your Kubernetes cluster.

Step 2: Running the Command

To retrieve information about the service account, use the following command:

kubectl get serviceaccount default -o yaml

This command fetches the details of the default service account associated with your Kubernetes deployment. The output will provide a YAML representation of the service account, including the associated GCP service account.

Step 3: Locating the GCP Service Account

Look for the field named secrets. The GCP service account information is stored as a secret within Kubernetes. Extract the name of the secret associated with the service account.

secrets:
- name: default-token-[random-string]

Step 4: Retrieving GCP Service Account Details

Use the secret name obtained in the previous step to fetch the details of the GCP service account:

kubectl get secret [secret-name] -o yaml

Replace [secret-name] with the actual name of the secret associated with your service account.

Step 5: Decoding Service Account Information

The output will contain a base64-encoded field named token. Decode this field to obtain the service account information:

echo "[base64-encoded-token]" | base64 --decode

Replace [base64-encoded-token] with the actual base64-encoded token obtained from the secret.

More Examples and Considerations

Example 1: Using Service Account Key

If your Kubernetes service is configured to use a service account key file, you can inspect the key file to determine the associated GCP service account:

cat [path-to-key-file].json

Example 2: Multiple Service Accounts

In scenarios where multiple service accounts are in use, consider examining the pod specifications to identify the explicitly defined service account.

kubectl get pod [pod-name] -o=jsonpath='{.spec.serviceAccountName}'

Identifying the GCP service account associated with your Kubernetes service is a fundamental aspect of managing your cloud-native applications. By following the steps outlined in this article, you can gain insights into the security context and permissions of your application, facilitating effective management and troubleshooting within the GCP environment.