DEV Community: Rohit Kalyan Kandulapati

Podman Cheatsheet

Rohit Kalyan Kandulapati — Mon, 03 Feb 2025 13:11:52 +0000

Images

Listing Images

podman images

Pulling an Image

podman pull jenkins

Deleting Images

podman rmi <image-name or image-id>

Remove un-used images at once

podman image prune

podman rmi $(podman images -aq)

Building images from a Dockerfile

# . represents that the Dockerfile is present in the location where you are running this command.
podman build -t podman-image:1.0 .

Saving images to your local in archive

podman image save -o image.tar <image-id>

Load a container from a stored archive

podman load -i archive_name.tar

Tagging an image

podman tag <image-id> target-image-name

# Tagging images with a tag
podman tag -t <image-id> target-image-name:tag

Containers

Listing the containers that are running.

podman ps

Listing all containers in your machine

podman ps -a

Running a container

# Running a container normally
podman run <image-id>

# Running a container in detached mode
podman run -d <image-id>

# Adding a name 
podman run -d --name jenkins <image-id>

Stopping a container

podman stop <container-id>

Starting a stopped container

podman start <container-id>

Removing a container

podman rm <container-id>

Logs of a container

podman logs <container-id>

# Watching logs 
podman logs --tail=100 -f <container-id>

Copying files from/to a container

# Copying files to a container
# It is better to copy files from you podman machine to a container rather than from your local.

# podman cp source_path destination_path

podman cp file_path_in_your_podman_machine container_id:path_in_your_container

# Copying files from your container to your podman machine
podman cp container_id:path_in_your_container file_path_in_your_podman_machine

Logging into a container

podman exec -it <container-id> /bin/bash

# Logging in as a root user
podman exec -it --user root <container-id> /bin/bash

Creating an image from a container

podaman commit <container-ID> image_name

Inspecting a container

podman inspect <container-id>

Network

Listing Networks

podman network ls

Creating a network

podman network create net-1

Removing a network

podman network rm net-1

Attaching network to a container

podman network connect <container-id>

Attaching network at while running the container

podman run -d --network net-1 --name jenkins <image-id>

Inspecting a network

podman network inspect net-1

Volumes

Creating a volume

podman volume create volume-1

Listing Volumes

podman volume ls

Removing Volumes

podman volume rm volume-1

Removing unused volumes in your machine

podman volume prune

Attaching Volume while running the container

podman run -d --volume volume-1:/var/jenkins_home --network net-1 --name jenkins <image-id>

Set up your own Ansible Lab using Docker

Rohit Kalyan Kandulapati — Sat, 25 Jan 2025 19:30:07 +0000

Hi there 👋
This is Rohit and this is my first post on Dev.to

I know finding the right infra for learning Ansible is hard but not impossible. Today we are going to setup our own ansible lab in our system, which don't have any restrictions and any time limits.

Prerequisites: Docker in your system, Interest in you to learn Ansible.

Steps to setup Ansible lab:

1. Pulling the image

Pull the ubuntu image
docker pull ubuntu

2. Setting Up docker network

Create a docker network with a specific subnet
docker network create ansible-network --subnet 192.168.1.0/24

3. Setting up Ansible Master Container

a. Run the ubuntu image.
docker run -d -it --name ansible-master --net ansible-network --hostname ans_master ubuntu

b. Login into the container
docker exec -it ansible-master /bin/bash

c. Run the below commands

# 1
apt update

# 2
apt install vim python-is-python3 openssh-client iputils-ping ansible -y

# 3
ssh-keygen
# you will be prompted for responses, just keep clicking enter.

4. Setting up Manage Container-1

You can use the below setup to add as many managed nodes as you want, you just need to change the container name.

a. Run the ubuntu image
docker run -d -it --name ansible-manage-1 --net ansible-network --ip 192.168.1.18 --hostname ans_master ubuntu

b. Login in to the container
docker exec -it ansible-manage-1 /bin/bash

c. Run the below commands

# 1
apt update

# 2
apt install vim python-is-python3 openssh-client openssh-server -y 

# 3
apt update

# 4
service ssh start

5. Password-less authentication

a. Copy the contents of .pub file under the path ~/.ssh/ on your control container.
b. Add that to ~/.ssh/authorized_keys in your managed containers. Create the file if that file is not present and you should do the same for all your managed containers.
c. Try running the below command in your control container.
ssh root@ans_manage
Enter yes.

Now you have successfully setup password-less authentication from your control container to managed container.

6. Validate using ping module

a. Create and inventory.ini file in your control node under /home/ubuntu and add the below contents. (Make sure you have exited from the ssh connection)

192.168.1.18 ansible_user=root

b. Run the below command
ansible -i /home/ubuntu/inventory.ini -m ping all
Just enter for one more time(last time).

Happy Learning 🎉🎉

Let us know in the comments if you find any difficulties.