Skip to content

Commit 37d1076

Browse files
committed
correct sidecar section of 1.28 release blog
Signed-off-by: Matthias Bertschy <[email protected]>
1 parent 9f89239 commit 37d1076

File tree

1 file changed

+15
-13
lines changed

1 file changed

+15
-13
lines changed

content/en/blog/_posts/2023-08-15-kubernetes-1.28-blog.md

Lines changed: 15 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -36,9 +36,9 @@ However, since the tested/supported skew between nodes and control planes is cur
3636

3737
## Generally available: recovery from non-graceful node shutdown
3838

39-
If a node shuts down down unexpectedly or ends up in a non-recoverable state (perhaps due to hardware failure or unresponsive OS), Kubernetes allows you to clean up afterwards and allow stateful workloads to restart on a different node. For Kubernetes v1.28, that's now a stable feature.
39+
If a node shuts down unexpectedly or ends up in a non-recoverable state (perhaps due to hardware failure or unresponsive OS), Kubernetes allows you to clean up afterward and allow stateful workloads to restart on a different node. For Kubernetes v1.28, that's now a stable feature.
4040

41-
This allows stateful workloads to failover to a different node successfully after the original node is shut down or in a non-recoverable state, such as the hardware failure or broken OS.
41+
This allows stateful workloads to fail over to a different node successfully after the original node is shut down or in a non-recoverable state, such as the hardware failure or broken OS.
4242

4343
Versions of Kubernetes earlier than v1.20 lacked handling for node shutdown on Linux, the kubelet integrates with systemd
4444
and implements graceful node shutdown (beta, and enabled by default). However, even an intentional
@@ -136,22 +136,24 @@ CDI provides a standardized way of injecting complex devices into a container (i
136136
## API awareness of sidecar containers (alpha) {#sidecar-init-containers}
137137

138138
Kubernetes 1.28 introduces an alpha `restartPolicy` field for [init containers](https://github.com/kubernetes/website/blob/main/content/en/docs/concepts/workloads/pods/init-containers.md),
139-
and uses that to indicate when an init container is also a _sidecar container_. The will start init containers with `restartPolicy: Always` in the order they are defined, along with other init containers. Instead of waiting for that sidecar container to complete before starting the main container(s) for the Pod, the kubelet only waits for
140-
the sidecar init container to have started.
141-
142-
The condition for startup completion will be that the startup probe succeeded (or if no startup probe is defined) and postStart handler is completed. This condition is represented with the field Started of ContainerStatus type. See the section "Pod startup completed condition" for considerations on picking this signal.
139+
and uses that to indicate when an init container is also a _sidecar container_.
140+
The kubelet will start init containers with `restartPolicy: Always` in the order
141+
they are defined, along with other init containers.
142+
Instead of waiting for that sidecar container to complete before starting the main
143+
container(s) for the Pod, the kubelet only waits for the sidecar init container to have started.
144+
145+
The kubelet will consider the startup for the sidecar container as being completed
146+
if the startup probe succeeds and the postStart handler is completed.
147+
This condition is represented with the field Started of ContainerStatus type.
148+
If you do not define a startup probe, the kubelet will consider the container
149+
startup to be completed immediately after the postStart handler completion.
143150

144151
For init containers, you can either omit the `restartPolicy` field, or set it to `Always`. Omitting the field
145152
means that you want a true init container that runs to completion before application startup.
146153

147154
Sidecar containers do not block Pod completion: if all regular containers are complete, sidecar
148155
containers in that Pod will be terminated.
149156

150-
For sidecar containers, the restart behavior is more complex than for init containers. In a Pod with
151-
`restartPolicy` set to `Never`, a sidecar container that fails during Pod startup will **not** be restarted
152-
and the whole Pod is treated as having failed. If the Pod's `restartPolicy` is `Always` or `OnFailure`,
153-
a sidecar that fails to start will be retried.
154-
155157
Once the sidecar container has started (process running, `postStart` was successful, and
156158
any configured startup probe is passing), and then there's a failure, that sidecar container will be
157159
restarted even when the Pod's overall `restartPolicy` is `Never` or `OnFailure`.
@@ -165,7 +167,7 @@ To learn more, read [API for sidecar containers](/docs/concepts/workloads/pods/i
165167
Kubernetes automatically sets a `storageClassName` for a PersistentVolumeClaim (PVC) if you don't provide
166168
a value. The control plane also sets a StorageClass for any existing PVC that doesn't have a `storageClassName`
167169
defined.
168-
Previous versions of Kubernetes also had this behavior; for Kubernetes v1.28 is is automatic and always
170+
Previous versions of Kubernetes also had this behavior; for Kubernetes v1.28 it is automatic and always
169171
active; the feature has graduated to stable (general availability).
170172

171173
To learn more, read about [StorageClass](/docs/concepts/storage/storage-classes/) in the Kubernetes
@@ -294,4 +296,4 @@ Have something you’d like to broadcast to the Kubernetes community? Share your
294296

295297
* Read more about what’s happening with Kubernetes on the [blog](https://kubernetes.io/blog/).
296298

297-
* Learn more about the [Kubernetes Release Team](https://github.com/kubernetes/sig-release/tree/master/release-team).
299+
* Learn more about the [Kubernetes Release Team](https://github.com/kubernetes/sig-release/tree/master/release-team).

0 commit comments

Comments
 (0)