feat: Add statefulset user guide

Signed-off-by: Harrison <harrisonliu_5@163.com>

content/en/docs/project-user-guide/application-workloads/statefulsets.md

@@ -7,8 +7,6 @@ description: 'Kubernetes StatefulSets'
 weight: 2240
 ---
 
-## What is the Statefulset
-
 StatefulSet is the workload API object used to manage stateful applications.
 
 Manages the deployment and scaling of a set of Pods, and provides guarantees about the ordering and uniqueness of these Pods.
@@ -17,6 +15,11 @@ Like a Deployment, a StatefulSet manages Pods that are based on an identical con
 
 If you want to use storage volumes to provide persistence for your workload, you can use a StatefulSet as part of the solution. Although individual Pods in a StatefulSet are susceptible to failure, the persistent Pod identifiers make it easier to match existing volumes to the new Pods that replace any that have failed.
 
+## Prerequisites
+
+- You need to create a workspace, project and `project-regular` account. Please refer to the [Getting Started with Multi-tenant Management](../../../quick-start/create-workspace-and-project) if not yet.
+- You need to sign in with `project-admin` account and invite `project-regular` to enter the corresponding project if not yet. Please refer to [Invite Member](../../../quick-start/create-workspace-and-project#task-3-create-a-project).
+
 ## Using StatefulSets
 
 StatefulSets are valuable for applications that require one or more of the following.
@@ -28,11 +31,11 @@ StatefulSets are valuable for applications that require one or more of the follo
 
 ## Create a StatefulSets
 
-In the kubesphere, when creating a StatefulSets, a Handless service is also created. When you had created, you can go to services to find it.
+In the kubesphere, when creating a StatefulSets, a **Handless** service is also created. When you had created, you can go to services to find it.
 
 ### Step 1: Click Create
 
- Into **Workloads**, choose **StatefulSets** and Click **Create**
+ Into **Workloads**, choose **StatefulSets** and click **Create**
 
 ![statefulsets](/images/docs/project-user-guide/workloads/statefulsets.png)
 
@@ -50,21 +53,21 @@ Click the **Add Container Image** area.
 
 ![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_form_2_container_btn.png)
 
-you can input or select the image which in the public docker hub or private image repository you want to use.
+You can input or select the image which in the public docker hub or private image repository you want to use.
 
 ![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_form_2_container_1.png)
 
 - **Image Name**
 
-  you can click the icon or input the image name to search it. kubesphere provide the Dockerhub image and your private image repository. If you want to use your private image repository, you should create a docker hub secret first in **Configurations** **Secrets**
+  You can click the icon or input the image name to search it. kubesphere provide the Dockerhub image and your private image repository. If you want to use your private image repository, you should create a docker hub secret first in **Configurations** **Secrets**
 
 - **Image Tag**
 
-  you can input tag like `imagename:tag`, If you do not specify, it will default to the latest version.
+  You can input tag like `imagename:tag`, If you do not specify, it will default to the latest version.
 
 - **container type**
 
-  choose Init Container，It means that to create the Init Container。 For more information about Init Container, please visit [Init Container](https://kubernetes.io/docs/concepts/workloads/pods/init-containers/?spm=a2c4g.11186623.2.19.16704b3e9qHXPb)
+  Choose Init Container，It means that to create the Init Container。 For more information about Init Container, please visit [Init Container](https://kubernetes.io/docs/concepts/workloads/pods/init-containers/?spm=a2c4g.11186623.2.19.16704b3e9qHXPb)
 
 ![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_form_2_container_2.png)
 
@@ -72,22 +75,42 @@ you can input or select the image which in the public docker hub or private imag
 
   The resource quota reserved by the container includes both CPU and memory resources. That is the container monopolizes the resource, preventing other services or processes from competing for resources due to insufficient resources, causing the application to become unavailable.
 
+  - CPU Request is `spec.containers[].resources.requests.cpu`. The CPU request can be exceeded.
+  - Memory Request is `spec.containers[].resource.memory`. The Memory request can be exceeded but the container may clear up when Node memory is insufficient
+
 - **Resource Limit**
 
   You can specify the upper limit of the resources that the application can use, including CPU and memory, to prevent excessive resources from being occupied. Among them, the unit of CPU resource is Core, and the unit is Mi
 
+  - CPU Limit is `spec.containers[].resources.limits.cpu`. The CPU limit can be exceeded for a short time, and the container will not be stopped.
+  - Memory Limit is `spec.containers[].resources.limits.memory`. The Memory Limit can not be exceeded. If it exceeds, the container may be stopped or scheduled to another machine with sufficient resources
+
 ![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_form_2_container_3.png)
 
-- **image pull policy**
-  - Use local image first (**ifNotPresent**): If the image exists locally, the local image is used, and the image is pulled when the local does not exist.
-  - Always pull the image (**Always**): It means that the image will be pulled from the container mirroring service every time it is deployed or expanded, instead of pulling the image locally.
-  - Only use a local image (**Never**): Only use a local image.
+- **Image Pull Policy**
+  - Use Local Image First (**ifNotPresent**): It means that pull the image only if it does not exist locally.
+  - Redownload Image (**Always**): It means that pull the image whenever the pod is started.
+  - Only Use Local Image  (**Never**): It means that whatever the image is exist or not, it doesn't pull.
 
-- **Health checkers**
+  {{< notice tip>}}
 
-    Support liveness and Readiness. The survival check is used to detect when to restart the container. For more information about health checks, please visit [Configure Liveness, Readiness, and Startup Probes](https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/?spm=a2c4g.11186623.2.23.16704b3e9qHXPb)。
+  - Default is **IfNotPresent**, but the image tag with `:latest` is default **Always**.
+  - Docker will check it when pulling the image, if MD5 has not changed, it will not pull.
+  - The `:latest` should be avoided as much as possible in the production environment, and the latest image can be automatically pulled by the `:latest` in the development environment.
 
-  - **HTTP** request is to send an HTTP get a request to the container. The supported parameters include:
+  {{< /notice >}}
+
+- **Health Checker**
+
+  Support **liveness**, **Readiness**, and **Startup**. The survival check is used to detect when to restart the container.
+
+  - `livenessProbe`：Indicates whether the container is running
+  - `readinessProbe`：Indicates whether the container is ready to serve the request
+  - `startupProbe`: Indicates whether the application in the container has been started
+
+  Both of liveness, Readiness, and Startup have included these configs:
+
+  - **HTTPGetAction**: Perform an HTTP Get request on the specified port and path on the IP address of the container. If the response status code is greater than or equal to 200 and less than 400, the diagnosis is considered successful. The supported parameters include:
     - **Scheme**：HTTP/HTTPS。
     - **Path**: The path to access the HTTP server.
     - **Port**: The access port or port name is exposed by the container. The port number must be between 1 and 65535.
@@ -98,7 +121,7 @@ you can input or select the image which in the public docker hub or private imag
     - **Success Threshold**: is `successThreshold`. Minimum consecutive successes for the probe to be considered successful after having failed. It defaults to 1 and must be 1 for liveness and startup. The minimum value is 1.
     - **Failure Threshold**: is `failureThreshold`. Minimum consecutive failures for the probe to be considered failed after having succeeded. It defaults to 3 and the minimum value is 1.
 
-  - **TCP** uses a TCP socket. With this configuration, the kubelet will attempt to open a socket to your container on the specified port. If it can establish a connection, the container is considered healthy, if it can't it is considered a failure. The supported parameters include:
+  - **TCPSocketAction**: Perform a TCP check on the specified port on the IP address of the container. If the port is open, the diagnosis is considered successful. The supported parameters include:
     - **Port**: The access port or port name is exposed by the container. The port number must be between 1 and 65535.
     - **Initial Delays**: is `initialDelaySeconds`. The number of seconds after the container has started before liveness probes are initiated, the default is 0 seconds.
     - **Period Seconds**: is `periodSeconds`.
@@ -107,8 +130,8 @@ you can input or select the image which in the public docker hub or private imag
     - **Success Threshold**: is `successThreshold`. Minimum consecutive successes for the probe to be considered successful after having failed. It defaults to 1 and must be 1 for liveness and startup. The minimum value is 1.
     - **Failure Threshold**: is `failureThreshold`. Minimum consecutive failures for the probe to be considered failed after having succeeded. It defaults to 3 and the minimum value is 1.
 
-  - **Commands** detects the health of the container by executing probe detection commands in the container. The supported parameters include:
-    - **Command**：is `exec.command`. A detection command used to detect the health of the container.
+  - **ExecAction**: Execute the specified command in the container. If the return code is 0 when the command exits, the diagnosis is considered successful. The supported parameters include:
+    - **Command**: is `exec.command`. A detection command used to detect the health of the container.
     - **Initial Delays**: is `initialDelaySeconds`. The number of seconds after the container has started before liveness probes are initiated, the default is 0 seconds.
     - **Period Seconds**: is `periodSeconds`.
       Probe frequency (in seconds), which defaults to 10 seconds. The minimum value is 1.
@@ -116,21 +139,27 @@ you can input or select the image which in the public docker hub or private imag
     - **Success Threshold**: is `successThreshold`. Minimum consecutive successes for the probe to be considered successful after having failed. It defaults to 1 and must be 1 for liveness and startup. The minimum value is 1.
     - **Failure Threshold**: is `failureThreshold`. Minimum consecutive failures for the probe to be considered failed after having succeeded. It defaults to 3 and the minimum value is 1.
 
+   For more information about health checks, please visit [Container Probes](https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/#container-probes).
+
 - **Start Command**
 
-  By default, the container runs the default image command. For more information about the command, please visit [Container Command](https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/).
+  By default, the container runs the default image command.
 
   - Run Command is the `command` of containers.
   - Parameters are the `args` of containers.
 
+  For more information about the command, please visit [Container Command](https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/).
+
 - **Environment Variables**
 
-  Supports configuring environment variables for Pod in the form of key-value pairs. For more information about the command, please visit [Pod variable](https://kubernetes.io/docs/tasks/inject-data-application/environment-variable-expose-pod-information/?spm=a2c4g.11186623.2.20.16704b3e9qHXPb)。
+  Supports configuring environment variables for Pod in the form of key-value pairs.
 
   - name：Set the name of the environment variable.
   - value：Set the value of the variable reference.
   - type：Set the type of environment variables, support customization, configuration items, keys, and variable/variable references.
 
+  For more information about the command, please visit [Pod variable](https://kubernetes.io/docs/tasks/inject-data-application/environment-variable-expose-pod-information/?spm=a2c4g.11186623.2.20.16704b3e9qHXPb).
+
 - **Container Security Context**
 
   A security context defines privilege and access control settings for a Pod or Container. [Pod Security Policies](https://kubernetes.io/docs/concepts/policy/pod-security-policy/).
@@ -145,10 +174,17 @@ you can input or select the image which in the public docker hub or private imag
 
 - **Update Strategy**
 
-  The `.spec.updateStrategy` field of StatefulSet allows you to configure and disable automatic scrolling update Pod containers, tags, resource requests or restrictions, and annotations.For more information about update strategy, please visit [Statefulset Update-Strategies](https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#update-strategies).
+  The `.spec.updateStrategy` field of StatefulSet allows you to configure and disable automatic scrolling update Pod containers, tags, resource requests or restrictions, and annotations.
 
-  - RollingUpdate (Recommended)
-  - OnDelete
+  - **RollingUpdate (Recommended)**
+
+    When  `.spec.template` should update, The Pods in the StatefulSet are automatically deleted and create a new Pod to replace. When updating, these Pods are performed in reverse order, sequentially deleting, creating, and waiting for the Pod to become Ready before proceeding to the next Pod update.
+
+  - **OnDelete**
+
+    When  `.spec.template` should update, The Pods in the StatefulSet are not automatically updated. The Pod must be manually deleted so that the controller can create a new Pod to react to its update.
+
+  For more information about the update strategy, please visit [Statefulset Update-Strategies](https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#update-strategies).
 
 - **The number of Pods when updated**
 
@@ -160,16 +196,50 @@ you can input or select the image which in the public docker hub or private imag
 
 - **Deployment Mode**
 
-  Select different deployment modes to change the affinity and anti-affinity of the inter-pod. In k8s, the affinity is used `podAffinity` and the anti-affinity is used `podAntiAffinity`. [Pod affinity](https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#inter-pod-affinity-and-anti-affinity)
+  Select different deployment modes to change the affinity and anti-affinity of the inter-pod. In k8s, the affinity is used `podAffinity` and the anti-affinity is used `podAntiAffinity`. In the Kubesphere both affinity and anti-affinity are set `preferredDuringSchedulingIgnoredDuringExecution`.
 
   - Pod Decentralized Deployment is mean anti-affinity
   - Pod Aggregation Deployment is mean affinity
 
+  For more information about affinity and anti-affinity, please visit  [Pod affinity](https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#inter-pod-affinity-and-anti-affinity)
+
 ### Step 4: Input Volumes Data
 
 ![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_form_3.png)
 
-StatefulSets can use the volume template, but you should create it in **Storage** before. For more information about volume, please visit [Volumes](../../storage/volumes)
+StatefulSets can use the volume template, but you should create it in **Storage** before.
+
+Mount Volume has 3 methods:
+
+- **Add Volume Template**: The volume Template is to dynamically create a PV. Bind the PV of the StorageClass type to the pod by setting `volumeClaimTemplates`.
+
+- **Add Volume**: Support EmptyDir and PersistentVolumeClaim.
+
+  In **Add Volume** there are 3 kinds of volumes:
+
+  - **Existing Volume**: Use *PVC* to mount.
+
+    Persistent storage volumes can be used to save user's persist data, Add Existing Volume means you need to create volumes in advance
+
+  - **Temporary Volume**: Use *emptyDir* to mount.
+
+    The temporary storage volume represents [emptyDir](https://kubernetes.cn/docs/concepts/storage/volumes/#emptydir), which is first created when a Pod is assigned to a Node, and exists as long as that Pod is running on that node. When a Pod is removed from a node for any reason, the data in the emptyDir is deleted forever.
+
+  - **HostPath**: Use *HostPath* to mount.
+
+    A HostPath volume mounts a file or directory from the host node's filesystem into your Pod. This is not something that most Pods will need, but it offers a powerful escape hatch for some applications.
+
+- **Mount ConfigMap or Secret**: Supports for configuring the key-value pairs ​​in ConfigMap or Secret via reference configuration center.
+
+  A secret volume is used to pass sensitive information, such as passwords, to Pods. Secret volumes are backed by tmpfs (a RAM-backed filesystem) so they are never written to non-volatile storage.
+
+  ConfigMap is used to store configuration data in the form of key-value pairs. The configMap resource provides a way to inject configuration data into Pods. The data stored in a ConfigMap object can be referenced in a volume of type configMap and then consumed by containerized applications running in a Pod.
+
+  - Set the value of the environment variable
+  - Set command parameters in the container
+  - Create a config file in the volume
+
+For more information about volume, please visit [Volumes](../../storage/volumes)
 
 ### Step 5: Input Advanced Data
 
@@ -183,14 +253,53 @@ StatefulSets can use the volume template, but you should create it in **Storage*
 
   Additional metadata settings for resources such as **Labels** and **Annotations**.
 
-## Operate Stateful
+## Check Statefulset Detail
+
+You can check the statefulSet detail via click statefulSet's name on the list.
+
+### Statefulset Operations
 
 ![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_list.png)
 
 You can click **More** to display what other operations about this Statefulset you can do.
 
-- Edit：you can edit the base data.
-- Edit Yaml：you can upload, download, or update the YAML file。
-- Redeploy：you can redeploy this Statefulset.
-- Delete: you can delete this Statefulset.
+- **Edit**：View and edit the base data.
+- **Edit Yaml**：View, upload, download, or update the YAML file。
+- **Redeploy**：Redeploy this Statefulset.
+- **Delete**: Delete the Statefulset.
 
+### Statefulset Detail View
+
+![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_detail.png)
+
+
+#### Statefulset Detail Operations
+
+You can click **More** to display what the operations about this Statefulset you can do.
+
+![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_detail_operation_btn.png)
+
+- **Revision Rollback**: Select the revision to rollback.
+- **Edit Service**: Set the port to expose the container image and the service port.
+- **Edit Config Template**：Set some config about Update Strategy, Container and Volume.
+- **Edit YAML**：View, upload, download, or update the YAML file。
+- **Redeploy**: Redeploy this Statefulset.
+- **Delete**: Delete the Statefulset, and return to the Statefulset list page.
+
+#### Resource Status
+
+![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_detail_state.png)
+
+- **Replica Status**: Increase or decrease the Pod Replica.
+- **Pods detail**
+
+  ![statefulsets](/images/docs/project-user-guide/workloads/statefulsets_detail_pod.png)
+
+  - The pod list provides the pod’s detail information(conditions, phase, node, pod ip, monitoring).
+  - You can view the container info by clicking the pod item.
+  - Click the container log icon to view the output logs of the container.
+  - You can view the pod detail page by clicking the pod name.
+
+#### Revision Records
+
+After the resource template of workload is changed, a new log will be generated and Pods will be rescheduled for a version update. The latest 10 versions will be saved by default. You can implement a redeployment based on the change log.