Labels and Annotations - Kubernetes Dashboard

Labels and annotations are key-value pairs that provide metadata for Kubernetes resources. This guide covers how to view, add, and manage labels and annotations through the Dashboard interface.

Overview

Kubernetes uses two types of metadata:

Labels

Identifying metadata used for selection and organization

Annotations

Non-identifying metadata for tools and libraries

Labels

Labels are key-value pairs attached to objects for identification and selection:

metadata:
  labels:
    app: nginx
    environment: production
    tier: frontend
    version: v1.2.3

Use cases:

Resource selection via label selectors
Service discovery and routing
Organizing resources by application, environment, or team
Scheduling and placement decisions

Annotations

Annotations store arbitrary non-identifying metadata:

metadata:
  annotations:
    kubernetes.io/change-cause: "Updated nginx to 1.21"
    prometheus.io/scrape: "true"
    prometheus.io/port: "9090"
    deployment.kubernetes.io/revision: "3"

Use cases:

Build/release information
Tool configuration (monitoring, logging, service mesh)
Documentation and contact information
Deployment history and rollout tracking

Viewing Labels and Annotations

In List Views

Resource list views display common labels:

Navigate to any resource type (Pods, Deployments, Services, etc.)
Labels are shown in the list view columns
Click on a label to filter resources with that label

In Detail Views

View all labels and annotations for a resource:

Open Resource

Click on any resource name to open its detail view

View Metadata Section

Scroll to the metadata section showing labels and annotations

Expand Lists

Click to expand the full list of labels or annotations

In YAML View

See the raw metadata:

Open resource detail view
Click the YAML tab
Find the metadata section:

metadata:
  name: nginx-deployment
  namespace: default
  labels:
    app: nginx
    tier: frontend
  annotations:
    deployment.kubernetes.io/revision: "1"
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"apps/v1","kind":"Deployment"...}

Adding Labels

Add labels through the Dashboard UI:

During Resource Creation

When creating applications via the form:

Access Creation Form

Navigate to Create → Create from form

Show Advanced Options

Expand the advanced options section

Add Labels

In the labels section, click Add Label

Enter Key-Value Pairs

Provide label key and value:

Key: environment
Value: production

Dashboard automatically adds the k8s-app label to deployments created via the form. This label is used for service discovery and dashboard organization.

Editing Existing Resources

Add labels to existing resources:

Open Resource

Navigate to the resource detail view

Edit YAML

Click the Edit button

Add Labels

Update the metadata.labels section:

metadata:
  labels:
    app: nginx
    team: platform  # New label
    cost-center: engineering  # New label

Save Changes

Click Update to apply changes

Adding Annotations

Add annotations for documentation and tool integration:

Via YAML Editor

metadata:
  annotations:
    # Documentation
    description: "Primary web application frontend"
    owner: "[email protected]"
    
    # Monitoring integration
    prometheus.io/scrape: "true"
    prometheus.io/port: "8080"
    prometheus.io/path: "/metrics"
    
    # Service mesh
    sidecar.istio.io/inject: "true"
    
    # Custom tooling
    company.com/backup-policy: "daily"
    company.com/pii-data: "false"

Common Annotations

Kubernetes System Annotations

kubernetes.io/change-cause: "Deployment reason"
kubernetes.io/description: "Resource description"
kubernetes.io/ingress.class: "nginx"
deployment.kubernetes.io/revision: "3"

Prometheus Annotations

prometheus.io/scrape: "true"
prometheus.io/port: "9090"
prometheus.io/path: "/metrics"
prometheus.io/scheme: "https"

Service Mesh Annotations

# Istio
sidecar.istio.io/inject: "true"
sidecar.istio.io/proxyCPU: "100m"
sidecar.istio.io/proxyMemory: "128Mi"

# Linkerd
linkerd.io/inject: "enabled"

Label Selectors

Use label selectors to filter and organize resources:

Equality-Based Selectors

Match labels exactly:

selector:
  app: nginx
  environment: production

This matches resources with both labels.

Set-Based Selectors

More flexible matching:

selector:
  matchLabels:
    app: nginx
  matchExpressions:
  - key: environment
    operator: In
    values:
    - production
    - staging
  - key: tier
    operator: NotIn
    values:
    - deprecated

Operators:

In: Label value is in the set
NotIn: Label value is not in the set
Exists: Label key exists
DoesNotExist: Label key doesn’t exist

Using Selectors in Dashboard

Filter resources by labels:

Navigate to any resource list view
Click a label value in the list
Dashboard filters to show only resources with that label

Label Best Practices

Use meaningful, hierarchical labels

Structure labels for clarity:

labels:
  app.kubernetes.io/name: wordpress
  app.kubernetes.io/instance: wordpress-prod
  app.kubernetes.io/version: "6.2.0"
  app.kubernetes.io/component: frontend
  app.kubernetes.io/part-of: blog-platform
  app.kubernetes.io/managed-by: helm

Follow Kubernetes recommended labels

Use recommended label keys:

app.kubernetes.io/name: Application name
app.kubernetes.io/instance: Unique instance identifier
app.kubernetes.io/version: Application version
app.kubernetes.io/component: Component within architecture
app.kubernetes.io/part-of: Higher-level application
app.kubernetes.io/managed-by: Tool managing the resource

Keep labels short and descriptive

Good:

env: prod
tier: frontend

Avoid:

environment_type_for_deployment: production
application_tier_classification: frontend-web-servers

Use consistent labeling schemes

Standardize across your organization:

# Consistent environment labels
env: dev | staging | prod

# Consistent tier labels  
tier: frontend | backend | database

# Consistent team ownership
team: platform | data | security

Don't store large data in annotations

Annotations are limited to 256KB total. For large data, use ConfigMaps or external storage.

Common Label Patterns

Application Identification

labels:
  app: wordpress
  app.kubernetes.io/name: wordpress
  app.kubernetes.io/instance: wordpress-prod-01

Environment Segregation

labels:
  environment: production
  env: prod

Team Ownership

labels:
  team: platform
  owner: platform-team

Release Tracking

labels:
  version: v1.2.3
  release: spring-2026

Cost Allocation

labels:
  cost-center: engineering
  project: customer-portal
  budget-code: ENG-2026-Q1

Service Discovery with Labels

Services use label selectors to find pods:

apiVersion: v1
kind: Service
metadata:
  name: nginx-service
spec:
  selector:
    app: nginx      # Matches pods with this label
    tier: frontend
  ports:
  - port: 80
    targetPort: 8080

Dashboard displays the label selector in the service detail view, showing which pods are selected by the service.

Deployment Selectors

Deployments use selectors to manage pods:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx        # Must match selector
        version: v1.21

Deployment selectors are immutable after creation. You cannot change the selector without deleting and recreating the deployment.

Label Validation

Labels must follow specific rules:

Label Keys

Optional prefix + name separated by /
Prefix: DNS subdomain (max 253 characters)
Name: max 63 characters
Characters: alphanumeric, -, _, .
Must start and end with alphanumeric

Valid:

app: nginx
app.kubernetes.io/name: wordpress
company.com/team: platform

Invalid:

-app: nginx                    # Can't start with -
app-: nginx                    # Can't end with -  
too-long-label-key-that-exceeds-sixty-three-characters-limit: value

Label Values

Max 63 characters
Can be empty
Characters: alphanumeric, -, _, .
Must start and end with alphanumeric (if non-empty)

Troubleshooting

Labels not showing in list view

Dashboard shows a limited set of common labels in list views. View the full list in the detail view or YAML tab.

Cannot change deployment selector

Deployment selectors are immutable. You must delete and recreate the deployment with a new selector.

Service not finding pods

Verify the service selector matches pod labels:

kubectl get pods -l app=nginx,tier=frontend
kubectl describe service nginx-service

Invalid label format

Ensure labels follow naming conventions:

Max 63 characters for name
Alphanumeric, -, _, . only
Start and end with alphanumeric

Next Steps

Managing Resources

Learn about resource management

Managing Applications

Deploy and manage applications

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User Guide

Architecture

Configuration

​Overview

Labels

Annotations

​Labels

​Annotations

​Viewing Labels and Annotations

​In List Views

​In Detail Views

​In YAML View

​Adding Labels

​During Resource Creation

​Editing Existing Resources

​Adding Annotations

​Via YAML Editor

​Common Annotations

​Label Selectors

​Equality-Based Selectors

​Set-Based Selectors

​Using Selectors in Dashboard

​Label Best Practices

​Common Label Patterns

​Application Identification

​Environment Segregation

​Team Ownership

​Release Tracking

​Cost Allocation

​Service Discovery with Labels

​Deployment Selectors

​Label Validation

​Label Keys

​Label Values

​Troubleshooting

​Next Steps

Managing Resources

Managing Applications

Build docs developers (and LLMs) love

Overview

Labels

Annotations

Viewing Labels and Annotations

In List Views

In Detail Views

In YAML View

Adding Labels

During Resource Creation

Editing Existing Resources

Adding Annotations

Via YAML Editor

Common Annotations

Label Selectors

Equality-Based Selectors

Set-Based Selectors

Using Selectors in Dashboard

Label Best Practices

Common Label Patterns

Application Identification

Environment Segregation

Team Ownership

Release Tracking

Cost Allocation

Service Discovery with Labels

Deployment Selectors

Label Validation

Label Keys

Label Values

Troubleshooting

Next Steps