Using Podman with Dockerfiles: Basic Guide

Podman is an open-source project and can be used to manage all of your containers, regardless of the container engine even if you do not utilize Podman as the container engine. The basic principles of the Podman runtime environment is only compatible with Linux operating systems. You can, however, manage containers on the Podman-running machine using a remote client for another operating system.

What is Podman?

Podman is a daemonless, open-source, Linux-native tool that makes it simple to identify, execute, build, share, and deploy applications that use Open Containers Initiative (OCI) containers and container images. Podman features a command line interface (CLI) that is familiar to anyone who has used the Docker Container Engine. Most users can just alias Docker to Podman without issue. Containers run by Podman can be either root or a non-privileged user. Podman manages the complete container ecosystem, including pods, containers, container images, and container volumes, with the libpod library.

Why Use Podman With Dockerfiles?

• Flexibility: Podman and Docker can function as standalone container management platforms. Switching between them is quick and simple owing to Podman, which has the same CLI and administrative interface as Docker.
• Security-Focused: Both Podman and Docker support the rootless option for operating containers. Podman operates the container as a non-root user by default, integrates natively with SELinux, and secures default settings.
• Lightweight & Efficient: Docker and Podman have distinct architectures that prioritize lightweight and efficiency. Podman has a daemon-less architecture, as opposed to Docker, which manages containers via a centrally managed Docker daemon.

Implementation of Podman: A Basic Example of Using Podman With Dockerfiles

Below is the step-by-step process of using Podman with Dockerfiles:

Step 1: Install Podman

First of all, Your package manager ought to display messages confirming the successful installation of Podman.

$ sudo apt install podman

Output:

Step 2: Make a Dockerfile

Now let's make a basic Dockerfile. We'll construct a container that runs a rudimentary Nginx web server in this example.

# Use an official Nginx image as a parent image
FROM nginx:alpine

# Copy a custom configuration file (if needed)
# COPY nginx.conf /etc/nginx/nginx.conf

# Expose port 80 for the web server
EXPOSE 80

Step 3: Create the Container Image

To create the container image, navigate to the directory where your Dockerfile is located and execute the Podman command as follows.

$ podman build -t my-nginx-image 

Output:

Step 4: Run the Container

The container ID will appear when you perform the podman run command.

$ podman run -d -p 8080:80 --name my-nginx-container my-nginx-image

Output:

Step 5: Check the Container

Next, You can use the following to see how your container is running.

$ podman ps

Output:

Step 6: Remove the Container

In the next step, you can remove the container by using the following command.

$ podman rm my-nginx-container

Output:

Step 7: Remove the Image

Lastly, Use these if you need to remove the image.

$ podman rmi my-nginx-image

Output:

Best Practices of Podman With Dockerfiles

• Use Namespaces and Cgroups: Podman facilitates resource allocation and security by supporting user namespaces and groups. Make sure you're making use of these features to improve control and isolation.
• Use Podman Pods for Grouping Containers: Form a Pod from of connected containers. This makes management easier and enables them to share network namespaces.
• Keep Images Minimal and Singularly Focused: Podman With Dockerfiles are typically used for stateless microservices that are designed to be scaled horizontally. This means that several container instances of the same Docker image will frequently run concurrently and need to be launched fast at random.
• Use ENV to Create Environment Variables: Environment variables are useful for passing information to your applications that can change at runtime. This frequently includes paths to executables that your script will use, package version numbers, and API keys.

Conclusion

In this article, we have learned about Podman: A Basic Example of Using Podman With Dockerfiles. Since Podman and Dockerfiles are interoperable, most Docker commands will function identically in Podman.