% podman-auto-update(1)

## NAME
podman-auto-update - Auto update containers according to their auto-update policy

## SYNOPSIS
**podman auto-update** [*options*]

## DESCRIPTION
`podman auto-update` looks up containers with a specified "io.containers.autoupdate" label (i.e., the auto-update policy).

If the label is present and set to "image", Podman reaches out to the corresponding registry to check if the image has been updated.
An image is considered updated if the digest in the local storage is different than the one of the remote image.
If an image must be updated, Podman pulls it down and restarts the systemd unit executing the container.

If "io.containers.autoupdate.authfile" label is present, Podman reaches out to corresponding authfile when pulling images.

At container-creation time, Podman looks up the "PODMAN_SYSTEMD_UNIT" environment variables and stores it verbatim in the container's label.
This variable is now set by all systemd units generated by `podman-generate-systemd` and is set to `%n` (i.e., the name of systemd unit starting the container).
This data is then being used in the auto-update sequence to instruct systemd (via DBUS) to restart the unit and hence to restart the container.

Note that `podman auto-update` relies on systemd and requires a fully-qualified image reference (e.g., quay.io/podman/stable:latest) to be used to create the container.
This enforcement is necessary to know which image to actually check and pull.
If an image ID was used, Podman would not know which image to check/pull anymore.

Moreover, the systemd units are expected to be generated with `podman-generate-systemd --new`, or similar units that create new containers in order to run the updated images.
Systemd units that start and stop a container cannot run a new image.


### Systemd Unit and Timer

Podman ships with a `podman-auto-update.service` systemd unit.  This unit is triggered daily at midnight by the `podman-auto-update.timer` systemd timer.  The timer can be altered for custom time-based updates if desired.  The unit can further be invoked by other systemd units (e.g., via the dependency tree) or manually via `systemctl start podman-auto-update.service`.


## OPTIONS

#### **--authfile**=*path*

Path of the authentication file. Default is ${XDG\_RUNTIME\_DIR}/containers/auth.json, which is set using `podman login`.
If the authorization state is not found there, $HOME/.docker/config.json is checked, which is set using `docker login`.

Note: You can also override the default path of the authentication file by setting the REGISTRY\_AUTH\_FILE
environment variable. `export REGISTRY_AUTH_FILE=path`

## EXAMPLES

```
# Start a container
$ podman run --label "io.containers.autoupdate=image" \
    --label "io.containers.autoupdate.authfile=/some/authfile.json" \
    -d busybox:latest top
bc219740a210455fa27deacc96d50a9e20516492f1417507c13ce1533dbdcd9d

# Generate a systemd unit for this container
$ podman generate systemd --new --files bc219740a210455fa27deacc96d50a9e20516492f1417507c13ce1533dbdcd9d
/home/user/containers/libpod/container-bc219740a210455fa27deacc96d50a9e20516492f1417507c13ce1533dbdcd9d.service

# Load the new systemd unit and start it
$ mv ./container-bc219740a210455fa27deacc96d50a9e20516492f1417507c13ce1533dbdcd9d.service ~/.config/systemd/user
$ systemctl --user daemon-reload
$ systemctl --user start container-bc219740a210455fa27deacc96d50a9e20516492f1417507c13ce1533dbdcd9d.service

# Auto-update the container
$ podman auto-update
container-bc219740a210455fa27deacc96d50a9e20516492f1417507c13ce1533dbdcd9d.service
```

## SEE ALSO
podman(1), podman-generate-systemd(1), podman-run(1), systemd.unit(5)
