Comparative Analysis of Docker and Podman Also Installation Steps

 

Docker and Podman are two popular containerization tools used for deploying applications. They have similarities but also some distinct differences that may influence your choice depending on your specific requirements. Here's a detailed comparison focusing on key aspects:

1. Architecture

• Docker:

  • Utilizes a client-server architecture.
  • Requires a daemon (dockerd) running in the background, which manages container lifecycle, images, and other functionalities.
  • Docker CLI communicates with this daemon.

• Podman:

  • Podman is daemon-less and does not require a central service running in the background.
  • Each container runs as a child process of the Podman process, which can improve security and resource usage.
  • Provides a Docker-compatible CLI and API.

2. Rootless Mode

• Docker:

  • Traditionally required root privileges, though it now supports a rootless mode.
  • Rootless Docker has some limitations compared to its rootful counterpart.

• Podman:

  • Designed with security in mind and supports rootless containers natively.
  • Runs containers in user namespaces, reducing security risks associated with root privileges.

3. Compatibility

• Docker:

  • Widely adopted with a large ecosystem of tools, libraries, and community support.
  • Docker Compose for multi-container applications.

• Podman:

  • Compatible with Docker images and supports Docker Compose via podman-compose.
  • Podman can replace Docker commands directly (e.g., podman run instead of docker run).

4. Networking

• Docker:

  • Has its own networking model, which includes bridge, overlay, and macvlan networks.
  • Requires docker network commands to manage network configurations.

• Podman:

  • Uses CNI (Container Network Interface) plugins for networking, providing flexibility and compatibility with Kubernetes.
  • Similar capabilities but can be more complex to set up for advanced networking configurations.

5. Kubernetes Integration

• Docker:

  • Kubernetes initially used Docker as a container runtime but is moving towards CRI-O and containerd due to deprecation of Docker Shim.
  • Still widely used in development and non-Kubernetes environments.

• Podman:

  • Designed to be Kubernetes-compatible, leveraging CRI-O principles.
  • Integrates well with Kubernetes, making it a suitable choice for Kubernetes deployments.

6. Performance

• Docker:

  • Generally efficient, but the daemon can be a single point of failure and may introduce overhead.

• Podman:

  • Potentially better performance due to its daemon-less architecture.
  • Each container is an individual process, allowing finer control and potentially lower overhead.

7. Management Tools

• Docker:

  • Docker Swarm for native clustering and orchestration (though less popular compared to Kubernetes).
  • Docker Hub for image repository and Docker Trusted Registry for enterprise use.

• Podman:

  • Supports similar orchestration with podman play kube to run Kubernetes YAML files.
  • Integration with Buildah for building images and Skopeo for image management.

8. Security

• Docker:

  • Has improved over the years, but the root privileges required by the daemon can pose security risks.
  • Supports AppArmor, SELinux, and seccomp for enhanced security.

• Podman:

• Prioritizes security with rootless mode and user namespaces.
• Similar security feature support (AppArmor, SELinux, seccomp).

Commands to Deploy a Basic Container

Ubuntu

Installing Docker:

1. Update package index and install dependencies:

   sudo apt-get update
   sudo apt-get install -y apt-transport-https ca-certificates curl software-properties-common
   

2. Add Docker’s official GPG key and repository:

   curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
   sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
   

3. Install Docker:

   sudo apt-get update
   sudo apt-get install -y docker-ce
   

4. Start and enable Docker:

   sudo systemctl start docker
   sudo systemctl enable docker
   

5. Run a test container:

   sudo docker run hello-world

Installing Podman:

1. Update package index and install Podman:

   . /etc/os-release
   sudo sh -c "echo 'deb http://ppa.launchpad.net/projectatomic/ppa/ubuntu ${UBUNTU_CODENAME} main' > /etc/apt/sources.list.d/podman.list"
   sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 2F9A3C2D2D5272C7
   sudo apt-get update
   sudo apt-get install -y podman
   

2. Run a test container:

   podman run hello-world

CentOS/Redhat/Rocky Linux

Installing Docker:

1. Update package index and install dependencies:

   sudo yum update -y
   sudo yum install -y yum-utils device-mapper-persistent-data lvm2
   

2. Add Docker’s official repository:

   
   sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
   

3. Install Docker:

   sudo yum install -y docker-ce

4. Start and enable Docker:

   sudo systemctl start docker
   sudo systemctl enable docker
   

5. Run a test container:

   sudo docker run hello-world

Installing Podman:

1. Update package index and install Podman:

   sudo yum update -y
   sudo yum install -y podman
   

2. Run a test container:

   podman run hello-world

Summary

Commands for Ubuntu:

• Docker:

  sudo apt-get update
  sudo apt-get install -y apt-transport-https ca-certificates curl software-properties-common
  curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
  sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
  sudo apt-get update
  sudo apt-get install -y docker-ce
  sudo systemctl start docker
  sudo systemctl enable docker
  sudo docker run hello-world
  

• Podman:

  . /etc/os-release
  sudo sh -c "echo 'deb http://ppa.launchpad.net/projectatomic/ppa/ubuntu ${UBUNTU_CODENAME} main' > /etc/apt/sources.list.d/podman.list"
  sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 2F9A3C2D2D5272C7
  sudo apt-get update
  sudo apt-get install -y podman
  podman run hello-world
  

Commands for CentOS/Redhat/Rocky Linux:

• Docker:

  sudo yum update -y
  sudo yum install -y yum-utils device-mapper-persistent-data lvm2
  sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
  sudo yum install -y docker-ce
  sudo systemctl start docker
  sudo systemctl enable docker
  sudo docker run hello-world
  

• Podman:

  sudo yum update -y
  sudo yum install -y podman
  podman run hello-world

If everything is set up correctly, you should see a message saying "Hello from Docker!" indicating that the installation was successful.

Conclusion

Both Docker and Podman are powerful tools for containerization, but your choice depends on your specific needs and environment:

• Choose Docker if:

  • You need a mature ecosystem with extensive community support.
  • You are already invested in Docker’s tooling and services.
  • You prefer the simplicity of Docker’s client-server architecture.

• Choose Podman if:

  • Security and running containers without root privileges are a priority.
  • You are looking for a more Kubernetes-native approach.
  • You want a daemon-less architecture for potentially better performance and security.

Both tools are capable and can coexist, with many users employing Docker for development and Podman for production environments due to its security and Kubernetes compatibility.