What is a Quadlet?

• File with a specific extension that lives in ~/.config/containers/systemd
• Systemd unit file generator
• Declarative Container Specification

Basic quadlet commands

• podman quadlet install
• podman quadlet list
• podman quadlet print
• podman quadlet rm

Basics of systemd: .service files

• Configuration files that give instructions to systemd on how to start, stop, restart
• Processes and daemons can be managed by unit files

Basic Systemd commands

• systemctl --user status
• systemctl --user start
• systemctl --user restart
• systemctl --user stop
• systemctl --user enable --now
• systemctl --user disable --now
• systemctl --user cat

Anatomy of a Quadlet

Source: your .container quadlet

# ~/.config/containers/systemd/minimal.container
[Container]
Image=quay.io/demo_quadlets/alpine:latest
                        

Generated: systemd unit (do not edit by hand)

# /run/user/1000/systemd/generator/minimal.service
# Automatically generated by /usr/lib/systemd/user-generators/podman-user-generator
#
[X-Container]
Image=quay.io/demo_quadlets/alpine:latest

[Unit]
Wants=podman-user-wait-network-online.service
After=podman-user-wait-network-online.service
SourcePath=/home/nsella/.config/containers/systemd/minimal.container
RequiresMountsFor=%t/containers

[Service]
Environment=PODMAN_SYSTEMD_UNIT=%n
KillMode=mixed
ExecStop=/usr/bin/podman rm -v -f -i systemd-%N
ExecStopPost=-/usr/bin/podman rm -v -f -i systemd-%N
Delegate=yes
Type=notify
NotifyAccess=all
SyslogIdentifier=%N
ExecStart=/usr/bin/podman run --name systemd-%N --replace --rm --cgroups=split --sdnotify=conmon -d quay.io/demo_quadlets/alpine:latest
                        

What systemd actually runs (ExecStart from the generated service)

/usr/bin/podman run \
    --name systemd-%N \
    --replace --rm \
    --cgroups=split \
    --sdnotify=conmon \
    -d quay.io/demo_quadlets/alpine:latest

Quadlet file types

• Container→.container
• Pod→.pod
• Kube→.kube
• Network→.network
• Volume→.volume
• Build→.build
• Image→.image
• Artifact→.artifact

Container unit file

Defines a single long-running container; maps to podman run.

podman run alpine:latest

[Container]
Image=alpine:latest
                        

mycontainer.container → mycontainer.service

Pod unit file

Creates a pod (shared network/IPC); containers join it with Pod=….

podman pod create

[Pod]
                        

mypod.pod → mypod.service

Kube unit file

Applies a Kubernetes manifest (Pod, Deployment, etc.) in one shot instead of many .container files.

podman kube play myawesomekubefile.yaml

[Kube]
Yaml=myawesomekubefile.yaml
                        

mykube.kube → mykube.service

Network unit file

Provisions a named network; containers reference it with Network=….

podman network create mynetwork

[Network]
                        

mynetwork.network → mynetwork-network.service

Volume unit file

Declares persistent disk; mount in containers with Volume=myvolume.volume:/path.

podman volume create myvolume

[Volume]
                        

myvolume.volume → myvolume-volume.service

Build unit file

Builds an image from a Containerfile next to the unit; other units can then run that tag.

podman build --tag localhost/imagename .

[Build]
ImageTag=localhost/imagename
SetWorkingDirectory=unit
                        

myimage.build → myimage-build.service

Image unit file

Pull-only service; containers use Image=myimage.image so start does not wait on the registry.

podman pull quay.io/centos/centos:latest

[Image]
Image=quay.io/centos/centos:latest
                        

myimage.image → myimage-image.service

Artifact unit file

Fetches OCI artifacts (models, bundles) for use with newer Podman features—not a runnable image by itself.

podman artifact pull quay.io/foobar/artifact:special

[Artifact]
Artifact=quay.io/foobar/artifact:special
                        

myartifact.artifact → myartifact-artifact.service

Demos