Integrating Podman with Kubernetes - A Comprehensive Guide#

As organizations increasingly adopt container-based infrastructure, the need for flexible and secure container tooling has never been greater. Podman, a daemonless container engine, provides a powerful alternative to Docker with excellent Kubernetes integration capabilities. This guide explores how to effectively use Podman in Kubernetes workflows, bridging the gap between local development and production deployment.

Understanding Podman and Kubernetes#

Podman and Kubernetes serve different but complementary roles in the container ecosystem:

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graph TD
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    A[Container Ecosystem] --> B[Development Tools]
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    A --> C[Orchestration Tools]
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    B --> D[Podman]
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    B --> E[Docker]
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    C --> F[Kubernetes]
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    C --> G[OpenShift]
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    D --> H[Local Development]
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    D --> I[CI/CD Integration]
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    D --> J[Kubernetes Manifest Generation]
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    F --> K[Container Orchestration]
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    F --> L[Production Deployment]
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    J --> K

Podman provides several advantages over traditional container engines:

Daemonless Architecture: No background daemon process required
Rootless Containers: Enhanced security through non-root container execution
OCI Compliance: Full compatibility with Open Container Initiative standards
Drop-in Replacement: Compatible with Docker commands through aliasing
Kubernetes Integration: Built-in tools for Kubernetes manifest generation

Podman to Kubernetes Workflow#

The core strength of Podman in a Kubernetes environment is its ability to seamlessly translate local containers to Kubernetes resources.

Basic Translation Workflow#

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# Run a container using Podman
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podman run -d --name webserver nginx:alpine
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# Generate Kubernetes manifest from the running container
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podman generate kube webserver > nginx-pod.yaml
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# Apply the manifest to a Kubernetes cluster
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kubectl apply -f nginx-pod.yaml
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# Alternatively, test locally using Podman's "play kube" feature
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podman play kube nginx-pod.yaml

This workflow allows developers to:

Test containers locally with Podman
Generate Kubernetes manifests automatically
Deploy the same containers to Kubernetes
Maintain consistency between development and production

Working with Pod Configurations#

Kubernetes pods often contain multiple containers. Podman supports this concept through its pod management features:

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# Create a pod with multiple containers
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podman pod create --name microservice-pod
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# Add containers to the pod
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podman run -dt --pod microservice-pod --name webapp nginx:alpine
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podman run -dt --pod microservice-pod --name api python:3.9-alpine python -m http.server 8000
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podman run -dt --pod microservice-pod --name redis redis:alpine
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# Generate Kubernetes manifest for the entire pod
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podman generate kube microservice-pod > microservice-pod.yaml

The generated YAML will include all containers in the pod with their respective configurations:

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apiVersion: v1
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kind: Pod
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metadata:
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  creationTimestamp: "2023-05-15T10:53:34Z"
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  labels:
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    app: microservice-pod
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  name: microservice-pod
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spec:
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  containers:
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    - image: nginx:alpine
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      name: webapp
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      ports:
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        - containerPort: 80
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          hostPort: 80
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          protocol: TCP
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    - image: python:3.9-alpine
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      name: api
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      command:
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        - python
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        - -m
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        - http.server
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        - "8000"
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      ports:
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        - containerPort: 8000
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          hostPort: 8000
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          protocol: TCP
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    - image: redis:alpine
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      name: redis
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      ports:
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        - containerPort: 6379
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          hostPort: 6379
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          protocol: TCP

Development to Production Workflow#

A complete workflow for taking an application from development to production with Podman and Kubernetes includes:

1. Building Container Images#

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# Create a containerized application
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mkdir myapp && cd myapp
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echo 'console.log("Hello from Podman & Kubernetes!");' > app.js
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# Create a Dockerfile
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cat > Dockerfile << EOF
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FROM node:16-alpine
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WORKDIR /app
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COPY app.js .
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CMD ["node", "app.js"]
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EOF
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# Build the image
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podman build -t myapp:1.0 .
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# Test locally
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podman run --rm myapp:1.0

2. Pushing to a Registry#

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# Tag for your registry
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podman tag myapp:1.0 registry.example.com/myapp:1.0
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# Push to registry
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podman push registry.example.com/myapp:1.0

3. Generating Kubernetes Resources#

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# Create a deployment container
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podman run -d --name myapp-deployment myapp:1.0
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# Generate Kubernetes manifest
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podman generate kube myapp-deployment > myapp-deployment.yaml
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# Modify for production use
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# (Add resource limits, replicas, etc.)

4. Deploying to Kubernetes#

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# Deploy to Kubernetes
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kubectl apply -f myapp-deployment.yaml
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# Verify deployment
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kubectl get pods

Integration with Local Kubernetes Development#

For local development with Kubernetes clusters, Podman integrates well with tools like Kind (Kubernetes in Docker):

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# Save Podman image to a tarball
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podman save -o myapp.tar myapp:1.0
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# Load image into Kind cluster
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kind load image-archive myapp.tar
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# Apply Kubernetes manifest
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kubectl apply -f myapp-deployment.yaml

Advanced Podman Kubernetes Features#

Security Context Generation#

Podman can generate Kubernetes security contexts from local container configurations:

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# Run a container with security options
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podman run --security-opt=no-new-privileges --cap-drop=ALL --cap-add=NET_BIND_SERVICE -d --name secure-nginx nginx
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# Generate manifest with security context
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podman generate kube secure-nginx > secure-nginx.yaml

The resulting YAML will include appropriate security contexts:

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apiVersion: v1
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kind: Pod
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metadata:
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  name: secure-nginx
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spec:
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  containers:
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    - name: secure-nginx
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      image: nginx
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      securityContext:
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        allowPrivilegeEscalation: false
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        capabilities:
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          drop:
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            - ALL
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          add:
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            - NET_BIND_SERVICE

Volume and ConfigMap Handling#

Podman can translate local volumes to Kubernetes persistent volumes and config maps:

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# Create a config file
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echo "server { listen 80; root /usr/share/nginx/html; }" > nginx.conf
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# Run with bind mount
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podman run -v ./nginx.conf:/etc/nginx/conf.d/default.conf:Z -d --name nginx-config nginx
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# Generate Kubernetes manifest
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podman generate kube nginx-config > nginx-with-config.yaml

The generated manifest will include volume definitions that you can adapt to PersistentVolumes or ConfigMaps.

Resource Limits and Requests#

Setting container resources in Podman translates to Kubernetes resource specifications:

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# Run container with resource limits
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podman run --memory=512m --cpus=0.5 -d --name limited-nginx nginx
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# Generate manifest with resource specifications
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podman generate kube limited-nginx > limited-nginx.yaml

Best Practices#

1. Maintain Image Consistency#

Use the same container images across development and production to avoid “works on my machine” problems:

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# Use specific image tags, not 'latest'
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podman run -d --name webapp myapp:1.0.3

2. Use Multi-Stage Builds#

Create smaller, more secure images using multi-stage builds:

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# Build stage
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FROM node:16-alpine AS builder
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WORKDIR /app
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COPY package*.json ./
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RUN npm install
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COPY . .
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RUN npm run build
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# Production stage
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FROM nginx:alpine
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COPY --from=builder /app/build /usr/share/nginx/html

3. Implement Rootless Containers#

Enhance security by running containers without root privileges:

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# Run rootless container
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podman run --user 1000:1000 -d --name rootless-nginx nginx

4. Test Generated Manifests#

Always validate generated Kubernetes manifests before applying to production:

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# Validate Kubernetes YAML
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kubectl apply --dry-run=client -f nginx-pod.yaml
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# Test with Podman first
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podman play kube nginx-pod.yaml

5. Augment Generated Manifests for Production#

Add production-specific configurations to generated manifests:

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# Add production enhancements
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apiVersion: v1
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kind: Pod
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metadata:
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  name: nginx
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  labels:
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    app: nginx
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    environment: production
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spec:
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  replicas: 3 # Add for Deployment
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  containers:
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    - name: nginx
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      image: nginx:1.21-alpine
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      resources:
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        limits:
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          memory: 512Mi
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          cpu: 500m
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        requests:
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          memory: 256Mi
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          cpu: 250m
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      livenessProbe: # Add health checks
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        httpGet:
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          path: /
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          port: 80

Troubleshooting#

Image Availability Issues#

If Kubernetes can’t find your images:

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# Verify image exists
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podman images | grep myapp
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# Check if image is pushed to an accessible registry
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podman push registry.example.com/myapp:1.0
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# Update image pull policy in Kubernetes manifest
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spec:
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  containers:
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  - name: myapp
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    image: registry.example.com/myapp:1.0
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    imagePullPolicy: Always

Resource Specification Errors#

If pods fail due to resource issues:

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# Check resource usage in Podman
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podman stats
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# Modify resource specifications
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podman generate kube --cpu-limit=500m --memory-limit=512Mi myapp

Security Context Problems#

If containers fail due to security issues:

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# Identify capabilities needed
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podman inspect --format '{{.EffectiveCapabilities}}' myapp
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# Generate Kubernetes manifest with appropriate security context
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podman generate kube --security-opt="seccomp=unconfined" myapp

Converting Complex Applications#

For more complex applications, consider using Podman Compose to convert Docker Compose files to Kubernetes:

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# Install podman-compose
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pip install podman-compose
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# Convert docker-compose to Kubernetes
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podman-compose -f docker-compose.yml kube > k8s-deployment.yaml

Comparison with Other Approaches#

Feature	Podman	Docker + Kompose	kubectl
Daemon Requirement	No	Yes	N/A
Root Privileges	Optional	Required	N/A
k8s Integration	Native	Via Kompose	Native
Security	Enhanced	Standard	N/A
OCI Compliance	Full	Full	N/A

Conclusion#

Integrating Podman with Kubernetes provides a seamless path from local development to production deployment. The ability to generate Kubernetes manifests directly from running containers bridges the development-operations gap and helps ensure consistency across environments.

By leveraging Podman’s rootless security features, daemonless architecture, and Kubernetes integration capabilities, teams can build more secure, reliable container workflows that work consistently from development laptops to production clusters.

Whether you’re managing a small application or a complex microservice architecture, Podman’s integration with Kubernetes offers a powerful toolset for modern container workflows.