Add auto-update support to `podman kube play`. Auto-update policies can
be configured for:
* the entire pod via the `io.containers.autoupdate` annotation
* a specific container via the `io.containers.autoupdate/$name` annotation
To make use of rollbacks, the `io.containers.sdnotify` policy should be
set to `container` such that the workload running _inside_ the container
can send the READY message via the NOTIFY_SOCKET once ready. For
further details on auto updates and rollbacks, please refer to the
specific article [1].
Since auto updates and rollbacks bases on Podman's systemd integration,
the k8s YAML must be executed in the `podman-kube@` systemd template.
For further details on how to run k8s YAML in systemd via Podman, please
refer to the specific article [2].
An examplary k8s YAML may look as follows:
```YAML
apiVersion: v1
kind: Pod
metadata:
annotations:
io.containers.autoupdate: "local"
io.containers.autoupdate/b: "registry"
labels:
app: test
name: test_pod
spec:
containers:
- command:
- top
image: alpine
name: a
- command:
- top
image: alpine
name: b
```
[1] https://www.redhat.com/sysadmin/podman-auto-updates-rollbacks
[2] https://www.redhat.com/sysadmin/kubernetes-workloads-podman-systemd
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>
Add a new package for proxying notify sockets and waiting for the
READY=1 message to appear. May subject to further changes in
future commits.
Tests make sure that it behaves properly.
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>
Valentin Rothberg
Daniel J Walsh