Creating and managing labels

Beta

This is a Beta release of cluster labels. This feature is not covered by any SLA or deprecation policy and might be subject to backward-incompatible changes.

This page provides an overview of cluster labels in GKE.

What are cluster labels?

A cluster label is a key-value pair that helps you organize your Google Cloud Platform clusters. You can attach a label to each resource, then filter the resources based on their labels. Information about labels is forwarded to the billing system, so you can break down your billing charges by label.

Common uses of cluster labels

Here are some common use cases for cluster labels:

• Team or cost center cluster labels: Add labels based on team or cost center to distinguish clusters owned by different teams (for example, team:research and team:analytics). You can use this type of label for cost accounting or budgeting.

• Component cluster labels: For example, component:redis, component:frontend, component:ingest, and component:dashboard.

• Environment or stage cluster labels: For example, environment:production and environment:test.

• State cluster labels: For example, state:active, state:readytodelete, and state:archive.

Note: Google Kubernetes Engine labels are distinct from labels in Kubernetes. GKE labels are arbitrary metadata attached to your resources that you can use to track usage and billing information. In Kubernetes, the system uses labels internally to associate cluster components and resources with one another and manage resource lifecycles.

Note: Do not include sensitive information in labels. This includes information that may be personally identifiable, such as an individual's name or title. Labels are not designed to handle sensitive information.

Requirements for cluster labels

The cluster labels applied to a resource must meet the following requirements:

• Each resource can have multiple cluster labels, up to a maximum of 64.
• Each cluster label must be a key-value pair.
• Keys have a minimum length of 1 character and a maximum length of 63 characters, and cannot be empty. Values can be empty, and have a maximum length of 63 characters.
• Keys and values can contain only lowercase letters, numeric characters, underscores, and dashes. All characters must use UTF-8 encoding, and international characters are allowed.
• The key portion of a cluster label must be unique. However, you can use the same key with multiple resources.
• Keys must start with a lowercase letter or international character.

Before you begin

To prepare for this task, perform the following steps:

• Ensure that you have enabled the Google Kubernetes Engine API.
Enable Google Kubernetes Engine API
• Ensure that you have installed the Cloud SDK.
• Set your default project ID:

  gcloud config set project [PROJECT_ID]

• If you are working with zonal clusters, set your default compute zone:

  gcloud config set compute/zone [COMPUTE_ZONE]

• If you are working with regional clusters, set your default compute region:

  gcloud config set compute/region [COMPUTE_REGION]

• Update gcloud to the latest version:

  gcloud components update

Note: You can override these default settings in gcloud commands using the --project, --zone, and --region operational flags.

About labeling clusters

In GKE, you apply labels at the cluster level. When you label a cluster, the label you have chosen propagates to all of the cluster's individual resources (such as nodes and persistent disks).

You can add, update, and remove cluster labels using Google Cloud Platform Console, the gcloud command-line tool, or the GKE API.

Note: Any labels you apply to your clusters propagate via a background process that runs hourly. It can take up to one hour for a label to appear on all resources associated with a given cluster. In addition, during the Beta release of cluster labels, labels only propagates to Compute Engine instances and Persistent Disks. Other resources such as forwarding rules and IPs are not labeled.

Getting a label fingerprint for API requests

When you update or add cluster labels using the GKE API, you need to provide the latest cluster label fingerprint with your request to prevent any conflicts with other requests.

Note: Cluster label fingerprints are not required for GCP Console or the gcloud tool.

To get the latest cluster label fingerprint, run a GET request for the appropriate cluster. For example:

GET https://container.googleapis.com/v1/projects/myproject/zones/us-central1-f/clusters/example-cluster

In the response, look for the labelFingerprint property:

200 OK

{

 "name": "mycluster",
 "description": "test-cluster",
 "initialNodeCount": 3,
 ...
 "resourceLabels": {
    "env": "test",
    ...
  },
  "labelFingerprint": "p1ty_9HoBk0="
}

Creating a cluster with labels

gcloud

To add labels when creating your cluster with the gcloud tool, run the following command:

gcloud container clusters create [CLUSTER_NAME] --labels [KEY]=[VALUE]

For example:

gcloud container clusters create example-cluster --labels env=dev

Console

To add labels when creating your cluster with GCP Console, perform the following steps:

1. Visit the Google Kubernetes Engine menu in GCP Console.

   Visit the Google Kubernetes Engine menu

2. Click Create cluster.

3. Configure your cluster as desired. Then, click Advanced options.

4. Click Add label.

5. Add labels as desired.

6. Click Create.

API

To include a label when creating your cluster, specify the resourceLabels object within the cluster object that you provide to projects.zones.clusters.create.

Adding or updating labels for existing clusters

gcloud

To update labels with the gcloud tool, run the following command:

gcloud container clusters update [CLUSTER_NAME] --update-labels [KEY]=[VALUE]

For example:

gcloud container clusters update example-cluster --update-labels env=dev,release=stable

If the cluster has existing labels you want to keep, you must include those labels along with any new labels that you want to add.

Console

To add or update labels using GCP Console, perform the following steps:

1. Visit the Google Kubernetes Engine menu in GCP Console.

   Visit the Google Kubernetes Engine menu

2. To add labels to a single cluster, click its Edit button, which looks like a pencil.

   1. Click Add labels and add one or more labels.
   2. Click Save.

3. To add labels to multiple clusters at once:

   1. Select the checkboxe the clusters you want to label.
   2. Click Show info panel to expand the labels column if it isn't already visible.
   3. Update or add new labels as desired.
   4. Click Save.

API

To update labels, make a POST request to the cluster's resourceLabels method with the latest fingerprint and a full list of labels to apply.

Similar to metadata and tags, if the cluster has existing labels you want to keep, you must include those labels in the request along with any new labels that you want to add.

For example, the following snippet makes a request to the resourceLabels method:

POST https://container.googleapis.com/v1/projects/myproject/zones/us-central1-f/clusters/example-cluster/resourceLabels

{
 "resourceLabels": {
  "env": "test",
  "an-existing-tag": ""
 },
 "labelFingerprint": "42WmSpB8rSM="
}

Removing cluster labels

gcloud

Using the gcloud command-line tool, run the update command with the --remove-labels flag. Provide a set of label keys to remove. For example:

gcloud container clusters update example-cluster --remove-labels env

Console

To remove a label using GCP Console, perform the following steps:

1. Visit the Google Kubernetes Engine menu in GCP Console.

   Visit the Google Kubernetes Engine menu

2. To remove labels from a single cluster, click its Edit button, which looks like a pencil.

   1. Click the X next to any label to remove it.
   2. Click Save.

3. To remove labels from multiple clusters at once:

   1. Select the checkboxes next to the clusters for which you want to remove labels.
   2. Click Show info panel to expand the labels column if it isn't already visible.
   3. Click the X next to all the labels you want to remove.
   4. Click Save.

API

In the API, make a POST request to the resourceLabels method for the appropriate cluster. Provide the current labelsFingerprint and an empty list of labels to remove all labels, or provide a list of labels you want to keep (omitting the labels you want to remove). For example:

Request

POST https://container.googleapis.com/v1/projects/myproject/zones/us-central1-f/clusters/example-cluster/resourceLabels

{
 "resourceLabels": { },
 "labelFingerprint": "42WmSpB8rSM="
}

What's next

Read the GKE overview.