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Merge pull request #31410 from chris-short/cbshort-issue-31394

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Update static-pod.md
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Kubernetes Prow Robot
2022-01-26 07:34:01 -08:00
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commit 37b7c6fd55
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content/en/docs/tasks/configure-pod-container/static-pod.md
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@@ -42,7 +42,7 @@ The `spec` of a static Pod cannot refer to other API objects
{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}} {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
This page assumes you're using {{< glossary_tooltip term_id="docker" >}} to run Pods, This page assumes you're using {{< glossary_tooltip term_id="cri-o" >}} to run Pods,
and that your nodes are running the Fedora operating system. and that your nodes are running the Fedora operating system.
Instructions for other distributions or Kubernetes installations may vary. Instructions for other distributions or Kubernetes installations may vary.
@@ -156,15 +156,20 @@ already be running.
You can view running containers (including static Pods) by running (on the node): You can view running containers (including static Pods) by running (on the node):
```shell ```shell
# Run this command on the node where the kubelet is running # Run this command on the node where the kubelet is running
docker ps crictl ps
``` ```
The output might be something like: The output might be something like:
```console
CONTAINER IMAGE CREATED STATE NAME ATTEMPT POD ID
129fd7d382018 docker.io/library/nginx@sha256:... 11 minutes ago Running web 0 34533c6729106
``` ```
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
f6d05272b57e nginx:latest "nginx" 8 minutes ago Up 8 minutes k8s_web.6f802af4_static-web-fk-node1_default_67e24ed9466ba55986d120c867395f3c_378e5f3c {{< note >}}
``` `crictl` outputs the image URI and SHA-256 checksum. `NAME` will look more like:
`docker.io/library/nginx@sha256:0d17b565c37bcbd895e9d92315a05c1c3c9a29f762b011a10c54a66cd53c9b31`.
{{< /note >}}
You can see the mirror Pod on the API server: You can see the mirror Pod on the API server:
@@ -172,8 +177,8 @@ You can see the mirror Pod on the API server:
kubectl get pods kubectl get pods
``` ```
``` ```
NAME READY STATUS RESTARTS AGE NAME READY STATUS RESTARTS AGE
static-web-my-node1 1/1 Running 0 2m static-web 1/1 Running 0 2m
``` ```
{{< note >}} {{< note >}}
@@ -181,7 +186,6 @@ Make sure the kubelet has permission to create the mirror Pod in the API server.
[PodSecurityPolicy](/docs/concepts/policy/pod-security-policy/). [PodSecurityPolicy](/docs/concepts/policy/pod-security-policy/).
{{< /note >}} {{< /note >}}
{{< glossary_tooltip term_id="label" text="Labels" >}} from the static Pod are {{< glossary_tooltip term_id="label" text="Labels" >}} from the static Pod are
propagated into the mirror Pod. You can use those labels as normal via propagated into the mirror Pod. You can use those labels as normal via
{{< glossary_tooltip term_id="selector" text="selectors" >}}, etc. {{< glossary_tooltip term_id="selector" text="selectors" >}}, etc.
@@ -190,34 +194,33 @@ If you try to use `kubectl` to delete the mirror Pod from the API server,
the kubelet _doesn't_ remove the static Pod: the kubelet _doesn't_ remove the static Pod:
```shell ```shell
kubectl delete pod static-web-my-node1 kubectl delete pod static-web
``` ```
``` ```
pod "static-web-my-node1" deleted pod "static-web" deleted
``` ```
You can see that the Pod is still running: You can see that the Pod is still running:
```shell ```shell
kubectl get pods kubectl get pods
``` ```
``` ```
NAME READY STATUS RESTARTS AGE NAME READY STATUS RESTARTS AGE
static-web-my-node1 1/1 Running 0 12s static-web 1/1 Running 0 4s
``` ```
Back on your node where the kubelet is running, you can try to stop the Docker Back on your node where the kubelet is running, you can try to stop the container manually.
container manually.
You'll see that, after a time, the kubelet will notice and will restart the Pod You'll see that, after a time, the kubelet will notice and will restart the Pod
automatically: automatically:
```shell ```shell
# Run these commands on the node where the kubelet is running # Run these commands on the node where the kubelet is running
docker stop f6d05272b57e # replace with the ID of your container crictl stop 129fd7d382018 # replace with the ID of your container
sleep 20 sleep 20
docker ps crictl ps
``` ```
``` ```console
CONTAINER ID IMAGE COMMAND CREATED ... CONTAINER IMAGE CREATED STATE NAME ATTEMPT POD ID
5b920cbaf8b1 nginx:latest "nginx -g 'daemon of 2 seconds ago ... 89db4553e1eeb docker.io/library/nginx@sha256:... 19 seconds ago Running web 1 34533c6729106
``` ```
## Dynamic addition and removal of static pods ## Dynamic addition and removal of static pods
@@ -230,14 +233,13 @@ The running kubelet periodically scans the configured directory (`/etc/kubelet.d
# #
mv /etc/kubelet.d/static-web.yaml /tmp mv /etc/kubelet.d/static-web.yaml /tmp
sleep 20 sleep 20
docker ps crictl ps
# You see that no nginx container is running # You see that no nginx container is running
mv /tmp/static-web.yaml /etc/kubelet.d/ mv /tmp/static-web.yaml /etc/kubelet.d/
sleep 20 sleep 20
docker ps crictl ps
``` ```
```console
CONTAINER IMAGE CREATED STATE NAME ATTEMPT POD ID
f427638871c35 docker.io/library/nginx@sha256:... 19 seconds ago Running web 1 34533c6729106
``` ```
CONTAINER ID IMAGE COMMAND CREATED ...
e7a62e3427f1 nginx:latest "nginx -g 'daemon of 27 seconds ago
```