Kubernetes Ops

---
name: kubernetes-ops
description: Deploy, scale, and manage Kubernetes workloads.
category: devops
risk: critical
source: https://github.com/BagelHole/DevOps-Security-Agent-Skills
source_repo: BagelHole/DevOps-Security-Agent-Skills
source_type: community
date_added: '2026-09-20'
license: MIT
license_source: https://github.com/BagelHole/DevOps-Security-Agent-Skills/blob/main/LICENSE
compatibility: Requires the relevant platform CLIs (kubectl, helm, terraform, git,
  CI runners) and authorized access to the target environment. Docs-only; helper scripts
  and templates not bundled.
metadata:
  author: devops-skills
  version: '1.0'
---

# Kubernetes Operations

Deploy and manage containerized applications on Kubernetes clusters.

## Prerequisites

- kubectl installed and configured
- Access to a Kubernetes cluster
- Basic understanding of containers

## Core Resources

### Deployment

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  labels:
    app: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp
        image: myapp:1.0.0
        ports:
        - containerPort: 8080
        resources:
          requests:
            memory: "128Mi"
            cpu: "100m"
          limits:
            memory: "256Mi"
            cpu: "500m"
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
          initialDelaySeconds: 10
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /ready
            port: 8080
          initialDelaySeconds: 5
          periodSeconds: 5
        env:
        - name: DATABASE_URL
          valueFrom:
            secretKeyRef:
              name: myapp-secrets
              key: database-url
```

### Service

```yaml
apiVersion: v1
kind: Service
metadata:
  name: myapp
spec:
  selector:
    app: myapp
  ports:
  - port: 80
    targetPort: 8080
  type: ClusterIP
---
# LoadBalancer for external access
apiVersion: v1
kind: Service
metadata:
  name: myapp-external
spec:
  selector:
    app: myapp
  ports:
  - port: 80
    targetPort: 8080
  type: LoadBalancer
```

### Ingress

```yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myapp
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  ingressClassName: nginx
  tls:
  - hosts:
    - myapp.example.com
    secretName: myapp-tls
  rules:
  - host: myapp.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp
            port:
              number: 80
```

## Configuration Management

### ConfigMap

```yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: myapp-config
data:
  config.yaml: |
    server:
      port: 8080
    logging:
      level: info
  APP_ENV: production
```

```yaml
# Using ConfigMap
containers:
- name: myapp
  envFrom:
  - configMapRef:
      name: myapp-config
  volumeMounts:
  - name: config
    mountPath: /etc/config
volumes:
- name: config
  configMap:
    name: myapp-config
```

### Secret

```yaml
apiVersion: v1
kind: Secret
metadata:
  name: myapp-secrets
type: Opaque
stringData:
  database-url: postgres://user:pass@host:5432/db
  api-key: secret-key-value
```

```bash
# Create secret from command line
kubectl create secret generic myapp-secrets \
  --from-literal=database-url='postgres://...' \
  --from-file=tls.crt=cert.pem
```

Secret values below are placeholders; Kubernetes Secrets are not encrypted merely by base64 encoding. Keep real values out of manifests, shell history and logs. Confirm the kubectl context and namespace before changes; inspect the diff and rollout health. The NetworkPolicy requires an enforcing CNI and its egress rules also need explicit DNS/external dependencies. LoadBalancer services can expose workloads publicly and incur charges.

## kubectl Commands

### Resource Management

```bash
# Apply configuration
kubectl apply -f deployment.yaml

# Get resources
kubectl get pods
kubectl get deployments
kubectl get services
kubectl get all -n myapp

# Describe resource
kubectl describe pod myapp-xxx

# Delete resource
kubectl delete -f deployment.yaml
kubectl delete pod myapp-xxx

# Edit resource
kubectl edit deployment myapp
```

### Debugging

```bash
# View logs
kubectl logs myapp-xxx
kubectl logs -f myapp-xxx --tail=100
kubectl logs myapp-xxx -c sidecar  # specific container

# Execute command
kubectl exec -it myapp-xxx -- /bin/sh

# Port forward
kubectl port-forward svc/myapp 8080:80
kubectl port-forward pod/myapp-xxx 8080:8080

# View events
kubectl get events --sort-by='.lastTimestamp'

# Debug pod
kubectl debug myapp-xxx -it --image=busybox
```

### Scaling

```bash
# Manual scaling
kubectl scale deployment myapp --replicas=5

# Autoscaling
kubectl autoscale deployment myapp \
  --min=2 --max=10 \
  --cpu-percent=80
```

## Horizontal Pod Autoscaler

```yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: myapp
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: myapp
  minReplicas: 2
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 80
  - type: Resource
    resource:
      name: memory
      target:
        type: Utilization
        averageUtilization: 80
```

## Persistent Storage

### PersistentVolumeClaim

```yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: myapp-data
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: standard
  resources:
    requests:
      storage: 10Gi
---
# Using PVC
containers:
- name: myapp
  volumeMounts:
  - name: data
    mountPath: /data
volumes:
- name: data
  persistentVolumeClaim:
    claimName: myapp-data
```

The StatefulSet below demonstrates identity and storage only. It lacks initialization credentials and the governing headless Service, and three independent PostgreSQL pods do not create replication or HA. Use an explicitly configured database topology or reviewed operator and tested backups for production data.

## StatefulSet

```yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: postgres
spec:
  serviceName: postgres
  replicas: 3
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
      - name: postgres
        image: postgres:15
        ports:
        - containerPort: 5432
        volumeMounts:
        - name: data
          mountPath: /var/lib/postgresql/data
  volumeClaimTemplates:
  - metadata:
      name: data
    spec:
      accessModes: ["ReadWriteOnce"]
      resources:
        requests:
          storage: 10Gi
```

## Jobs and CronJobs

### Job

```yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: migration
spec:
  template:
    spec:
      containers:
      - name: migrate
        image: myapp:1.0.0
        command: ["./migrate.sh"]
      restartPolicy: Never
  backoffLimit: 3
```

### CronJob

```yaml
apiVersion: batch/v1
kind: CronJob
metadata:
  name: backup
spec:
  schedule: "0 2 * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: backup
            image: backup-tool:latest
            command: ["./backup.sh"]
          restartPolicy: OnFailure
```

## Network Policies

```yaml
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: myapp-network-policy
spec:
  podSelector:
    matchLabels:
      app: myapp
  policyTypes:
  - Ingress
  - Egress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          app: frontend
    ports:
    - protocol: TCP
      port: 8080
  egress:
  - to:
    - podSelector:
        matchLabels:
          app: database
    ports:
    - protocol: TCP
      port: 5432
```


## Contents

- [Resource Quotas](references/details.md)
- [Rolling Updates](references/details.md)
- [Common Issues](references/details.md)
- [Best Practices](references/details.md)
- [Related Skills](references/details.md)

## When to Use This Skill

Use this skill when:
- Deploying applications to Kubernetes
- Managing pods, deployments, and services
- Configuring resource limits and scaling
- Troubleshooting Kubernetes workloads
- Setting up networking and ingress

## Limitations

- Guidance executes against real environments: confirm target, blast radius, and rollback plan before applying anything.
- Never deploy to production without explicit approval. Docs-only import: upstream scripts and templates not bundled.

### Example

```bash
git status && git diff --stat
kubectl diff -f manifest.yaml
```

> Adapted from [BagelHole/DevOps-Security-Agent-Skills](https://github.com/BagelHole/DevOps-Security-Agent-Skills) (MIT); frontmatter, When to Use/Limitations, and safety boundaries added for upstream compliance. Docs-only import: helper scripts and templates not bundled.