From f4e873c4e10502dd0a7fb14cc2fd87b12760a318 Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Tue, 10 Mar 2020 08:32:19 +0100 Subject: auto updates Add support to auto-update containers running in systemd units as generated with `podman generate systemd --new`. `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. We consider an image to be 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 container. Note that the restarting sequence relies on systemd. 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 this implementation of auto-updates relies on systemd and requires a fully-qualified image reference to be used to create the container. This enforcement is necessary to know which image to actually check and pull. If we used an image ID, we would not know which image to check/pull anymore. Fixes: #3575 Signed-off-by: Valentin Rothberg --- contrib/systemd/auto-update/podman-auto-update.service | 11 +++++++++++ 1 file changed, 11 insertions(+) create mode 100644 contrib/systemd/auto-update/podman-auto-update.service (limited to 'contrib/systemd/auto-update/podman-auto-update.service') diff --git a/contrib/systemd/auto-update/podman-auto-update.service b/contrib/systemd/auto-update/podman-auto-update.service new file mode 100644 index 000000000..b63f24230 --- /dev/null +++ b/contrib/systemd/auto-update/podman-auto-update.service @@ -0,0 +1,11 @@ +[Unit] +Description=Podman auto-update service +Documentation=man:podman-auto-update(1) +Wants=network.target +After=network-online.target + +[Service] +ExecStart=/usr/bin/podman auto-update + +[Install] +WantedBy=multi-user.target default.target -- cgit v1.2.3-54-g00ecf