Podman

Podman

Start Podman

 podman machine start

Images

List Images

 podman images

Pull an image

 podman pull docker.io/library/httpd

Run an image

 podman run -dt -p 8080:80/tcp docker.io/library/httpd
 
 podman run -it --entrypoint="/bin/sh" docker.io/library/httpd
 
 podman run -it -v /home/user/project:/app --entrypoint="/bin/bash" python:3.9.13-buster

• The -d will run the container in detach mode, so you wont see any console.
• The -t command connects the container to your terminal so it will not exit after it runs.

The following command with -rm will clean up the container and remove any persists data.

 podman run -rm docker.io/library/httpd

To commit a container to the list of podman images.

 podman commit {id}

Continue a container This will start back up an exited container, it will continue where you left off.

 podman start {id}

Get in to a running container

  podman exec -it {id} /bin/sh

List running images

 podman ps -a

Remove Image

 podman rmi {image_sha}

Load an Image

 Worked
 cat cs-oci.tar | podman load
 
 Did not work.
 podman load oci-archive:cs-oci.tar:latest

Update the tag for an image

 podman tag e7b8dd57dec6 cs:latest

Containers

List all containers

 podman ps -a

Remove Container

 podman rm ff22b3bfecc1

Pods

Create a pod

 podman pod create --name mypod

List pods

 podman pod list

Start pod

 podman pod start {podname}

Stop pod

 podman pod stop {podname}

List all processes with pods

 podman ps -a --pod

Volume

Volume in Podman can be a virtual volume that is mounted through Podman. This virtual volume can be exported or imported as well.

You can also setup to point to a local host directory but because Podman is rootless Podman will need access to the directory, by either permissions on the directory or the user that runs the container from Podman.

Create Virtual Volume

 podman volume create myvolume

Export Virtual Volume

 podman volume export myvolume --output myvolume.tar

Repositories

To login to a repository. The below example is for harbor but could be used for others.

 podman login --username JDOE --password {cli_secret}  https://registry.harbor-url.com/

Build

To build and avoid any cached layers use the following.

 podman build --no-cache -t $container_name:$container_tag .

Logs

View Logs

 podman logs ff22b3bfecc1

Stop the latest container

 podman stop ff22b3bfecc1

Kube

Generate kubernetes yaml

 podman generate kube -f infra.yaml mypod

Load kubernetes yaml

 podman play kube infra.yaml

Kubernetes File

1. Kubernetes setup for CS.

 apiVersion: v1
 kind: ConfigMap
 metadata:
   name: cs-config
 data:
   CS_DATABASE_MONGODB_EMBEDED_ENABLED: "false"
   SPRING_DATA_MONGODB_HOST: "localhost"
 ---
 apiVersion: v1
 kind: Pod
 metadata:
   name: mypod
   labels:
     app: mypod
 spec:
   containers:
     - name: database
       image: docker.io/library/mongo:4.4.13
       securityContext:
         runAsUser: 0
       volumeMounts:
         - name: mongodb-data-volume
           mountPath: /data/db
     - name: application
       image: cs:latest
       ports:
         - containerPort: 8080
           hostPort: 8080
       envFrom:
         - configMapRef:
            name: cs-config
   volumes:
     - name: mongodb-data-volume
       persistentVolumeClaim:
         claimName: mongodb-data-storage

Examples

Example run MongoDB

 podman run \ 
   --detach \ 
   --publish 27017:27017 \
   --userns=keep-id \ 
   --volume ./mongo-data:/data/db \ 
   --name some-mongo \ 
   mongo:4.4.13 
 
 # --detach, -d - Detached mode: run the container in the background and print the new container ID. The default is false
 # --publish, -p - Publish a container’s port, or range of ports, to the host.
 # --userns - Because podman runs rootless we need to assign a user that can access the local volumn.  This sets the podman user to the same user who ran the podman command.
 # --volume, -v - Create a bind mount.
 # --name - Assign a name to the container.

Example running with pods This is a test to see how apps can talk between each other in a podman network within a pod.

Create the pod

 podman pod create --userns=keep-id --publish 8080:8080 --name mypod

 podman run --detach --volume ./mongo-data:/data/db --pod mypod --name some-mongo mongo:4.4.13

 podman run --detach --pod mypod --name myapp -e SPRING_DATA_MONGODB_HOST="localhost" -e CS_DATABASE_MONGODB_EMBEDED_ENABLED="false" e7b8dd57dec6

 Not used - only for debug
 podman run -it --pod mypod --name myapp --volume ./config:/config --entrypoint "/bin/sh" e7b8dd57dec6