Labels vs annotations

/*@jsxRuntime automatic @jsxImportSource react*/
const {useMDXComponents: _provideComponents} = arguments[0];
function _createMdxContent(props) {
  const _components = Object.assign({
    p: "p",
    pre: "pre",
    code: "code",
    h2: "h2",
    h3: "h3",
    ul: "ul",
    li: "li",
    a: "a"
  }, _provideComponents(), props.components), {OpenShiftLocal, KubeBadge} = _components;
  if (!KubeBadge) _missingMdxReference("KubeBadge", true);
  if (!OpenShiftLocal) _missingMdxReference("OpenShiftLocal", true);
  return <><_components.p>{"When describing pods and other resources, you can see two sets of key value pairs. One is called Labels and the other Annotations."}</_components.p>{"\n"}<_components.p>{"Below you can see just a part of oc describe output that lists both labels and annotations."}</_components.p>{"\n"}<_components.pre><_components.code className="language-bash">{"oc -n openshift-console describe pod console\n\nName:                 console-85458bcc5b-t7mqs\nNamespace:            openshift-console\nPriority:             2000000000\nPriority Class Name:  system-cluster-critical\nNode:                 crc-gh9wd-master-0/192.168.126.11\nStart Time:           Wed, 20 Nov 2019 08:58:40 -0700\nLabels:               app=console\n                      component=ui\n                      pod-template-hash=85458bcc5b\nAnnotations:          console.openshift.io/console-config-version: 13677\n                      console.openshift.io/image:\n                        quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:2695...8ef\n                      console.openshift.io/infrastructure-config-version: 598\n                      console.openshift.io/oauth-secret-version: 13688\n                      console.openshift.io/oauth-serving-cert-config-version: 10994\n                      console.openshift.io/proxy-config-version: 618\n"}</_components.code></_components.pre>{"\n"}<_components.p>{"I get to use labels quite often, and I hardly ever use annotations. I asked myself what are they and what is their purpose? From the example above it seems that labels are more concise than annotations. It is because they serve different purposes."}</_components.p>{"\n"}<_components.p>{"Labels should be used by end users. If something is meant to be used by a person, put it into a label."}</_components.p>{"\n"}<_components.p>{"Annotations on the other hand are dedicated to be used for technical purposes. You can see in the example above that the Annotation "}<_components.code>{"kubernetes.io/created-by"}</_components.code>{" contains some JSON. Other values are similar to what you can find in the Labels."}</_components.p>{"\n"}<_components.h2>{"Documentation"}</_components.h2>{"\n"}<_components.p>{"The official documentation for OpenShift and Kubernetes serve quite a few examples for both. Just search for annotation or label on the pages below to get a better feeling on how they are used."}</_components.p>{"\n"}<_components.h3>{"Annotations"}</_components.h3>{"\n"}<_components.ul>{"\n"}<_components.li>{"OpenShift Docs: "}<_components.a href="https://docs.openshift.com/container-platform/4.10/networking/routes/route-configuration.html#nw-route-specific-annotations_route-configuration">{"Route-specific annotations"}</_components.a></_components.li>{"\n"}<_components.li>{"OpenShift Docs: "}<_components.a href="https://docs.openshift.com/container-platform/4.10/openshift_images/triggering-updates-on-imagestream-changes.html">{"Triggering updates on imagestream changes"}</_components.a></_components.li>{"\n"}<_components.li>{"OpenShift Docs: "}<_components.a href="https://docs.openshift.com/container-platform/4.10/security/certificates/service-serving-certificate.html#add-service-certificate_service-serving-certificate">{"Securing service traffic using service serving certificates"}</_components.a></_components.li>{"\n"}<_components.li>{"OpenShift Docs: "}<_components.a href="https://docs.openshift.com/container-platform/4.10/nodes/pods/nodes-pods-secrets.html#nodes-pods-secrets-troubleshooting_nodes-pods-secrets">{"Troubleshootin secrets"}</_components.a></_components.li>{"\n"}<_components.li>{"OpenShift Docs: "}<_components.a href="https://docs.openshift.com/container-platform/4.10/networking/multiple_networks/attaching-pod.html">{"Attaching a pod to an additional network"}</_components.a></_components.li>{"\n"}<_components.li>{"Kubernetes Docs: "}<_components.a href="https://kubernetes.io/docs/concepts/overview/working-with-objects/annotations/">{"Annotations"}</_components.a>{" – Kubernetes documentation about annotations"}</_components.li>{"\n"}</_components.ul>{"\n"}<_components.h3>{"Labels"}</_components.h3>{"\n"}<_components.ul>{"\n"}<_components.li>{"OpenShift Docs: "}<_components.a href="https://docs.openshift.com/container-platform/4.10/nodes/scheduling/nodes-scheduler-pod-topology-spread-constraints.html">{"Controlling pod placement by using pod topology spread constraints"}</_components.a></_components.li>{"\n"}<_components.li>{"OpenShift Docs: "}<_components.a href="https://docs.openshift.com/container-platform/4.10/applications/deployments/what-deployments-are.html">{"Understanding Deployment and DeploymentConfig objects"}</_components.a></_components.li>{"\n"}<_components.li>{"Kubernetes Docs: "}<_components.a href="https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/">{"Labels and Selectors"}</_components.a>{" – Kubernetes documentation about labels"}</_components.li>{"\n"}</_components.ul>{"\n"}<_components.h2>{"Environment"}</_components.h2>{"\n"}<_components.p>{"The commands were executed using "}<OpenShiftLocal />{" and the following client/server versions of OpenShift."}</_components.p>{"\n"}<KubeBadge client="4.10.9" server="4.10.9" kubernetes="v1.23.5+9ce5071" /></>;
}
function MDXContent(props = {}) {
  const {wrapper: MDXLayout} = Object.assign({}, _provideComponents(), props.components);
  return MDXLayout ? <MDXLayout {...props}><_createMdxContent {...props} /></MDXLayout> : _createMdxContent(props);
}
return {
  default: MDXContent
};
function _missingMdxReference(id, component) {
  throw new Error("Expected " + (component ? "component" : "object") + " `" + id + "` to be defined: you likely forgot to import, pass, or provide it.");
}



When describing pods and other resources, you can see two sets of key value pairs. One is called Labels and the other Annotations.

Below you can see just a part of oc describe output that lists both labels and annotations.

```bash
oc -n openshift-console describe pod console

Name:                 console-85458bcc5b-t7mqs
Namespace:            openshift-console
Priority:             2000000000
Priority Class Name:  system-cluster-critical
Node:                 crc-gh9wd-master-0/192.168.126.11
Start Time:           Wed, 20 Nov 2019 08:58:40 -0700
Labels:               app=console
                      component=ui
                      pod-template-hash=85458bcc5b
Annotations:          console.openshift.io/console-config-version: 13677
                      console.openshift.io/image:
                        quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:2695...8ef
                      console.openshift.io/infrastructure-config-version: 598
                      console.openshift.io/oauth-secret-version: 13688
                      console.openshift.io/oauth-serving-cert-config-version: 10994
                      console.openshift.io/proxy-config-version: 618
```

I get to use labels quite often, and I hardly ever use annotations. I asked myself what are they and what is their purpose? From the example above it seems that labels are more concise than annotations. It is because they serve different purposes.

Labels should be used by end users. If something is meant to be used by a person, put it into a label.

Annotations on the other hand are dedicated to be used for technical purposes. You can see in the example above that the Annotation `kubernetes.io/created-by` contains some JSON. Other values are similar to what you can find in the Labels.

## Documentation

The official documentation for OpenShift and Kubernetes serve quite a few examples for both. Just search for annotation or label on the pages below to get a better feeling on how they are used.

### Annotations

- OpenShift Docs: [Route-specific annotations](https://docs.openshift.com/container-platform/4.10/networking/routes/route-configuration.html#nw-route-specific-annotations_route-configuration)
- OpenShift Docs: [Triggering updates on imagestream changes](https://docs.openshift.com/container-platform/4.10/openshift_images/triggering-updates-on-imagestream-changes.html)
- OpenShift Docs: [Securing service traffic using service serving certificates](https://docs.openshift.com/container-platform/4.10/security/certificates/service-serving-certificate.html#add-service-certificate_service-serving-certificate)
- OpenShift Docs: [Troubleshootin secrets](https://docs.openshift.com/container-platform/4.10/nodes/pods/nodes-pods-secrets.html#nodes-pods-secrets-troubleshooting_nodes-pods-secrets)
- OpenShift Docs: [Attaching a pod to an additional network](https://docs.openshift.com/container-platform/4.10/networking/multiple_networks/attaching-pod.html)
- Kubernetes Docs: [Annotations](https://kubernetes.io/docs/concepts/overview/working-with-objects/annotations/) – Kubernetes documentation about annotations

### Labels

- OpenShift Docs: [Controlling pod placement by using pod topology spread constraints](https://docs.openshift.com/container-platform/4.10/nodes/scheduling/nodes-scheduler-pod-topology-spread-constraints.html)
- OpenShift Docs: [Understanding Deployment and DeploymentConfig objects](https://docs.openshift.com/container-platform/4.10/applications/deployments/what-deployments-are.html)
- Kubernetes Docs: [Labels and Selectors](https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/) – Kubernetes documentation about labels

## Environment

The commands were executed using <OpenShiftLocal/> and the following client/server versions of OpenShift.

<KubeBadge client='4.10.9' server='4.10.9' kubernetes='v1.23.5+9ce5071'/>


---
index: 3
publishDateTime: '2023-02-19T04:30:00+0200'
isPublished: true
path: /openshift-morsels/03-labels-vs-annotations
group: openshift-morsels
morsel:
  group: basic-knowhow
categories:
- Morsels
- OpenShift
title: 'Labels vs annotations'

---

When describing pods and other resources, you can see two sets of key value pairs. One is called Labels and the other Annotations.

Below you can see just a part of oc describe output that lists both labels and annotations.

```bash
oc -n openshift-console describe pod console

Name:                 console-85458bcc5b-t7mqs
Namespace:            openshift-console
Priority:             2000000000
Priority Class Name:  system-cluster-critical
Node:                 crc-gh9wd-master-0/192.168.126.11
Start Time:           Wed, 20 Nov 2019 08:58:40 -0700
Labels:               app=console
                      component=ui
                      pod-template-hash=85458bcc5b
Annotations:          console.openshift.io/console-config-version: 13677
                      console.openshift.io/image:
                        quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:2695...8ef
                      console.openshift.io/infrastructure-config-version: 598
                      console.openshift.io/oauth-secret-version: 13688
                      console.openshift.io/oauth-serving-cert-config-version: 10994
                      console.openshift.io/proxy-config-version: 618
```

I get to use labels quite often, and I hardly ever use annotations. I asked myself what are they and what is their purpose? From the example above it seems that labels are more concise than annotations. It is because they serve different purposes.

Labels should be used by end users. If something is meant to be used by a person, put it into a label.

Annotations on the other hand are dedicated to be used for technical purposes. You can see in the example above that the Annotation `kubernetes.io/created-by` contains some JSON. Other values are similar to what you can find in the Labels.

## Documentation

The official documentation for OpenShift and Kubernetes serve quite a few examples for both. Just search for annotation or label on the pages below to get a better feeling on how they are used.

### Annotations

- OpenShift Docs: [Route-specific annotations](https://docs.openshift.com/container-platform/4.10/networking/routes/route-configuration.html#nw-route-specific-annotations_route-configuration)
- OpenShift Docs: [Triggering updates on imagestream changes](https://docs.openshift.com/container-platform/4.10/openshift_images/triggering-updates-on-imagestream-changes.html)
- OpenShift Docs: [Securing service traffic using service serving certificates](https://docs.openshift.com/container-platform/4.10/security/certificates/service-serving-certificate.html#add-service-certificate_service-serving-certificate)
- OpenShift Docs: [Troubleshootin secrets](https://docs.openshift.com/container-platform/4.10/nodes/pods/nodes-pods-secrets.html#nodes-pods-secrets-troubleshooting_nodes-pods-secrets)
- OpenShift Docs: [Attaching a pod to an additional network](https://docs.openshift.com/container-platform/4.10/networking/multiple_networks/attaching-pod.html)
- Kubernetes Docs: [Annotations](https://kubernetes.io/docs/concepts/overview/working-with-objects/annotations/) – Kubernetes documentation about annotations

### Labels

- OpenShift Docs: [Controlling pod placement by using pod topology spread constraints](https://docs.openshift.com/container-platform/4.10/nodes/scheduling/nodes-scheduler-pod-topology-spread-constraints.html)
- OpenShift Docs: [Understanding Deployment and DeploymentConfig objects](https://docs.openshift.com/container-platform/4.10/applications/deployments/what-deployments-are.html)
- Kubernetes Docs: [Labels and Selectors](https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/) – Kubernetes documentation about labels

## Environment

The commands were executed using <OpenShiftLocal/> and the following client/server versions of OpenShift.

<KubeBadge client='4.10.9' server='4.10.9' kubernetes='v1.23.5+9ce5071'/>
