kubectl get resources by label with OR operator

kubectl

Kubernetes

resource management

querying labels

OR operator

kubectl get resources by label with OR operator

System Design practice on Codemia

Work through 120+ system design problems with detailed solutions, from rate limiters to multi-region storage.

Practice system design

Kubernetes

Introduction

Kubernetes label selectors support AND logic natively (comma-separated requirements), but do not support an OR operator directly. To select resources matching label A or label B, you use the set-based in operator: -l 'key in (value1, value2)'. For OR across different keys, you must run multiple kubectl commands or use field selectors in combination. Understanding the distinction between equality-based and set-based selectors is key to effective label querying.

AND Logic (Native — Comma Separated)

bash

1# AND: resources with BOTH app=web AND env=prod
2kubectl get pods -l app=web,env=prod
3
4# This is equivalent to:
5# app=web AND env=prod

Comma-separated label selectors are always AND. Every condition must match.

OR Logic with `in` Operator (Same Key, Different Values)

The in operator matches resources where a key has any of the listed values:

bash

1# OR: pods where env is "staging" OR "production"
2kubectl get pods -l 'env in (staging, production)'
3
4# OR: pods where app is "web" OR "api" OR "worker"
5kubectl get pods -l 'app in (web, api, worker)'
6
7# Combine with AND: app is web or api, AND tier=frontend
8kubectl get pods -l 'app in (web, api),tier=frontend'

The in operator provides OR semantics for a single key.

OR Across Different Keys

There is no native way to express "label A=x OR label B=y" in a single selector. You need multiple queries:

bash

1# Get pods with app=web OR tier=frontend (different keys)
2# Option 1: Two separate commands
3kubectl get pods -l app=web
4kubectl get pods -l tier=frontend
5
6# Option 2: Combine output and deduplicate
7kubectl get pods -l app=web -o name; kubectl get pods -l tier=frontend -o name | sort -u
8
9# Option 3: Use --output with jq for clean results
10{ kubectl get pods -l app=web -o json; kubectl get pods -l tier=frontend -o json; } | \
11  jq -s '.[0].items + .[1].items | unique_by(.metadata.name) | .[].metadata.name'

Negation with `notin` and `!=`

bash

1# Pods where env is NOT production
2kubectl get pods -l 'env notin (production)'
3
4# Equivalent
5kubectl get pods -l 'env!=production'
6
7# Pods where env is NOT staging AND NOT production
8kubectl get pods -l 'env notin (staging, production)'

Existence and Non-Existence Selectors

bash

1# Pods that HAVE the "app" label (any value)
2kubectl get pods -l app
3
4# Pods that DO NOT have the "app" label
5kubectl get pods -l '!app'
6
7# Pods with "app" label AND env=prod
8kubectl get pods -l 'app,env=prod'

Practical Examples

Select All Non-System Pods

bash

# Pods NOT in kube-system related apps
kubectl get pods --all-namespaces -l 'app notin (kube-dns, coredns, kube-proxy)'

Select Pods by Multiple Environments

bash

# All pods in dev, staging, or canary
kubectl get pods -l 'env in (dev, staging, canary)'

Select by Version Range

bash

# Pods running version v1 or v2
kubectl get pods -l 'version in (v1, v2)'

Delete by Label

bash

1# Delete all pods matching a label selector
2kubectl delete pods -l 'env in (dev, test)'
3
4# Delete pods with specific app label
5kubectl delete pods -l app=temp-worker

Apply to Other Resource Types

bash

1# Services with specific labels
2kubectl get services -l 'tier in (frontend, backend)'
3
4# Nodes with specific roles
5kubectl get nodes -l 'node-role.kubernetes.io/worker'
6
7# Deployments matching app label
8kubectl get deployments -l 'app in (web, api)'

Using Labels in YAML Manifests

Label selectors in Kubernetes resources use the same syntax:

yaml

1# Service selecting pods with OR on version
2apiVersion: v1
3kind: Service
4metadata:
5  name: my-service
6spec:
7  selector:
8    app: web        # Only equality-based selectors allowed in Service
9  ports:
10    - port: 80
11---
12# NetworkPolicy with set-based selectors
13apiVersion: networking.k8s.io/v1
14kind: NetworkPolicy
15metadata:
16  name: allow-web-and-api
17spec:
18  podSelector:
19    matchExpressions:
20      - key: app
21        operator: In
22        values: ["web", "api"]   # OR: app=web OR app=api
23      - key: env
24        operator: NotIn
25        values: ["test"]         # AND: env != test

In Deployments and ReplicaSets

yaml

1apiVersion: apps/v1
2kind: Deployment
3metadata:
4  name: web-deployment
5spec:
6  selector:
7    matchLabels:
8      app: web                    # Equality-based
9    matchExpressions:
10      - key: version
11        operator: In
12        values: ["v1", "v2"]     # Set-based OR
13  template:
14    metadata:
15      labels:
16        app: web
17        version: v1

Label Selector Summary Table

Selector	Syntax	Example
Equality	`key=value`	`app=web`
Inequality	`key!=value`	`env!=test`
Set membership (OR)	`key in (v1,v2)`	`env in (dev,staging)`
Set exclusion	`key notin (v1,v2)`	`env notin (prod)`
Exists	`key`	`app`
Does not exist	`!key`	`!temporary`
AND	`,` (comma)	`app=web,env=prod`

Common Pitfalls

Expecting OR with comma: kubectl get pods -l app=web,app=api does NOT mean OR. It means app=web AND app=api, which matches nothing (a label cannot have two values). Use app in (web, api) for OR.
Quoting in expressions in bash: The parentheses in in (val1, val2) must be quoted to prevent shell interpretation. Always wrap in single quotes: -l 'app in (web, api)'. Without quotes, bash tries to expand the parentheses as a subshell.
Service selectors only support equality: Kubernetes Service objects only accept matchLabels (equality-based), not matchExpressions (set-based). You cannot use in/notin in a Service selector. Use a separate Service per label value or restructure labels.
Spaces in in expressions: in(val1,val2) without a space after in may fail. Use in (val1, val2) with spaces for reliability.
Label key naming: Label keys follow [prefix/]name format. The name segment must be 63 characters or fewer. Keys with slashes like app.kubernetes.io/name must be quoted in selectors: -l 'app.kubernetes.io/name=myapp'.

Summary

Use in (value1, value2) for OR logic on the same label key
Comma-separated selectors are always AND, not OR
OR across different keys requires multiple kubectl commands
Use notin for exclusion and !key for non-existence checks
Quote selectors containing parentheses to prevent shell expansion
In YAML manifests, use matchExpressions with operator: In for set-based OR selectors

System Design Fundamentals

Build a strong foundation in designing scalable, reliable distributed systems.

View the course

Track what you have practised

A free account saves your progress, solutions and study plan across every problem on Codemia.

System Design practice on Codemia

Work through 120+ system design problems with detailed solutions, from rate limiters to multi-region storage.

Practice system design

kubectl get resources by label with OR operator

System Design practice on Codemia

Introduction

AND Logic (Native — Comma Separated)

OR Logic with in Operator (Same Key, Different Values)

OR Across Different Keys

Negation with notin and !=

Existence and Non-Existence Selectors

Practical Examples

Select All Non-System Pods

Select Pods by Multiple Environments

Select by Version Range

Delete by Label

Apply to Other Resource Types

Using Labels in YAML Manifests

In Deployments and ReplicaSets

Label Selector Summary Table

Common Pitfalls

Summary

Related reading

System Design Fundamentals

Track what you have practised

System Design practice on Codemia

OR Logic with `in` Operator (Same Key, Different Values)

Negation with `notin` and `!=`