Reword static pod task page

content/en/docs/tasks/configure-pod-container/static-pod.md

@@ -0,0 +1,243 @@
+---
+reviewers:
+- jsafrane
+title: Create static Pods
+content_template: templates/task
+---
+
+{{% capture overview %}}
+
+
+*Static Pods* are managed directly by the kubelet daemon on a specific node,
+without the {{< glossary_tooltip text="API server" term_id="kube-apiserver" >}}
+observing them.
+Unlike Pods that are managed by the control plane (eg, a
+{{< glossary_tooltip text="Deployment" term_id="deployment" >}};
+instead, the kubelet watches each static Pod (and restarts it if it crashes).
+There are no health checks for the containers in a static Pod.
+
+Static Pods are always bound to one {{< glossary_tooltip term_id="kubelet" >}} on a specific node.
+
+Kubelet automatically tries to create a {{< glossary_tooltip text="mirror Pod" term_id="mirror-pod" >}}
+on the Kubernetes API server for each static Pod.
+This means that the Pods running on a node are visible on the API server,
+but cannot be controlled from there.
+
+{{< note >}}
+If you are running clustered Kubernetes and are using static
+Pods to run a Pod on every node, you should probably be using a
+{{< glossary_tooltip text="DaemonSet" term_id="daemonset" >}}
+instead.
+{{< /note >}}
+
+{{% /capture %}}
+
+{{% capture prerequisites %}}
+
+{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
+
+This page assumes you're using {{< glossary_tooltip term_id="docker" >}} to run Pods,
+and that your nodes are running the Fedora operating system.
+Instructions for other distributions or Kubernetes installations may vary.
+
+
+{{% /capture %}}
+
+
+{{% capture steps %}}
+
+## Create a static pod {#static-pod-creation}
+
+You can configure a static Pod two different ways: either by using configuration file(s) or by HTTP.
+
+### Filesystem-hosted static Pod manifest {#configuration-files}
+
+The configuration files are just standard Pod definitions in JSON or YAML format in a specific directory. Use `kubelet --pod-manifest-path=<the directory>` to start the kubelet or add the `staticPodPath: <the directory>` field in the [KubeletConfiguration file](/docs/tasks/administer-cluster/kubelet-config-file), which periodically scans the directory and creates/deletes static Pods as YAML/JSON files appear/disappear there.
+Note that the kubelet will ignore files starting with dots when scanning the specified directory.
+
+For example, this is how to start a simple web server as a static Pod:
+
+1. Choose a node where you want to run the static Pod. In this example, it's `my-node1`.
+
+    ```shell
+    ssh my-node1
+    ```
+
+2. Choose a directory, say `/etc/kubelet.d` and place a web server Pod definition there, e.g. `/etc/kubelet.d/static-web.yaml`:
+
+```shell
+# Run this command on the node where kubelet is running
+mkdir /etc/kubelet.d/
+cat <<EOF >/etc/kubelet.d/static-web.yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  name: static-web
+  labels:
+    role: myrole
+spec:
+  containers:
+    - name: web
+      image: nginx
+      ports:
+        - name: web
+          containerPort: 80
+          protocol: TCP
+EOF
+```
+
+3. Configure your kubelet on the node to use this directory by running it with `--pod-manifest-path=/etc/kubelet.d/` argument or add the `staticPodPath: <the directory>` field in the [KubeletConfiguration file](/docs/tasks/administer-cluster/kubelet-config-file).
+    On Fedora edit `/etc/kubernetes/kubelet` to include this line:
+
+    ```
+    KUBELET_ARGS="--cluster-dns=10.254.0.10 --cluster-domain=kube.local --pod-manifest-path=/etc/kubelet.d/"
+    ```
+
+4. Restart the kubelet. On Fedora, you would run:
+
+    ```shell
+    # Run this command on the node where the kubelet is running
+    systemctl restart kubelet
+    ```
+
+### Web-hosted static pod manifest {#pods-created-via-http}
+
+Kubelet periodically downloads a file specified by `--manifest-url=<URL>` argument
+and interprets it as a JSON/YAML file that contains Pod definitions.
+Similar to how [filesystem-hosted manifests](#configuration-files) work, the kubelet
+refetches the manifest on a schedule. If there are changes to the list of static
+Pods, the kubelet applies them.
+
+If you want to use this approach, create a YAML file:
+
+```yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  name: static-web
+  labels:
+    role: myrole
+spec:
+  containers:
+    - name: web
+      image: nginx
+      ports:
+        - name: web
+          containerPort: 80
+          protocol: TCP
+```
+
+and store it on a web server so that you can pass the URL of that file to the kubelet.
+
+Configure the kubelet on your selected node to use this web manifest by running it with `--manifest-url=<manifest-url>`
+
+    On Fedora, edit `/etc/kubernetes/kubelet` to include this line:
+
+    ```
+    KUBELET_ARGS="--cluster-dns=10.254.0.10 --cluster-domain=kube.local --manifest-url=<manifest-url>`
+    ```
+
+Now, restart the kubelet. On Fedora, you would run:
+
+    ```shell
+    # Run this command on the node where the kubelet is running
+    systemctl restart kubelet
+    ```
+
+
+
+## Observe static pod behavior {#behavior-of-static-pods}
+
+When the kubelet starts, it automatically starts all defined static Pods. As you have
+defined a static Pod and restarted the kubelet, the new static Pod should
+already be running.
+
+You can view running containers (including static Pods) by running (on the node):
+```shell
+# Run this command on the node where kubelet is running
+docker ps
+```
+
+The output might be something like:
+
+```
+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
+```
+
+You can see the mirror Pod on the API server:
+
+```shell
+kubectl get pods
+```
+```
+NAME                       READY     STATUS    RESTARTS   AGE
+static-web-my-node1        1/1       Running   0          2m
+```
+
+{{< note >}}
+Make sure the kubelet has permission to create the mirror Pod in the API server. If not, the creation request is rejected by the API server. See
+[PodSecurityPolicy](/docs/concepts/policy/pod-security-policy/).
+{{< /note >}}
+
+
+{{< 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
+{{< glossary_tooltip term_id="selector" text="selectors" >}}, etc.
+
+If you try to use `kubectl` to delete the mirror Pod from the API server,
+the kubelet _doesn't_ remove the static Pod:
+
+```shell
+kubectl delete pod static-web-my-node1
+```
+```
+pod "static-web-my-node1" deleted
+```
+You can see that the Pod is still running:
+```shell
+kubectl get pods
+```
+```
+NAME                       READY     STATUS    RESTARTS   AGE
+static-web-my-node1        1/1       Running   0          12s
+```
+
+Back on your node where the kubelet is running, you can try to stop the Docker
+container manually.
+You'll see that, after a time, the kubelet will notice and will restart the Pod
+automatically:
+
+```shell
+# Run these commands on the node where the kubelet is running
+docker stop f6d05272b57e # replace with the ID of your container
+sleep 20
+docker ps
+```
+```
+CONTAINER ID        IMAGE         COMMAND                CREATED       ...
+5b920cbaf8b1        nginx:latest  "nginx -g 'daemon of   2 seconds ago ...
+```
+
+## Dynamic addition and removal of static pods
+
+The running kubelet periodically scans the configured directory (`/etc/kubelet.d` in our example) for changes and adds/removes Pods as files appear/disappear in this directory.
+
+```shell
+# This assumes you are using filesystem-hosted static Pod configuration
+# Run these commands on the node where the kubelet is running
+#
+mv /etc/kubelet.d/static-web.yaml /tmp
+sleep 20
+docker ps
+# You see that no nginx container is running
+mv /tmp/static-web.yaml  /etc/kubelet.d/
+sleep 20
+docker ps
+```
+```
+CONTAINER ID        IMAGE         COMMAND                CREATED           ...
+e7a62e3427f1        nginx:latest  "nginx -g 'daemon of   27 seconds ago
+```
+
+{{% /capture %}}

static/_redirects

@@ -295,6 +295,7 @@
 /docs/tasks/administer-cluster/romana-network-policy/     /docs/tasks/administer-cluster/network-policy-provider/romana-network-policy/ 301
 /docs/tasks/administer-cluster/running-cloud-controller.md     /docs/tasks/administer-cluster/running-cloud-controller/ 301
 /docs/tasks/administer-cluster/share-configuration/     /docs/tasks/access-application-cluster/configure-access-multiple-clusters/ 301
+/docs/tasks/administer-cluster/static-pod/ /docs/tasks/configure-pod-container/static-pod/ 301
 /docs/tasks/administer-cluster/upgrade-1-6/      /docs/tasks/administer-cluster/upgrade-downgrade/upgrade-1-6/ 301
 /docs/tasks/administer-cluster/weave-network-policy/     /docs/tasks/administer-cluster/network-policy-provider/weave-network-policy/ 301
 /docs/tasks/configure-pod-container/apply-resource-quota-limit/     /docs/tasks/administer-cluster/apply-resource-quota-limit/ 301