### Install Kuboard Beta Version

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-dashboard.md

Apply the beta version of Kuboard and its metrics server. Ensure you are on the master node if following the Kubernetes installation guide from kuboard.cn.

```sh
kubectl apply -f https://kuboard.cn/install-script/kuboard-beta.yaml
kubectl apply -f https://addons.kuboard.cn/metrics-server/0.3.7/metrics-server.yaml
```

--------------------------------

### Manual Installation Script for Kubernetes Components

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubernetes.md

This is the content of the manual installation script for Kubernetes components. It achieves the same result as the quick installation method.

```shell
set -e

# Install docker
apt-get update && apt-get install -y apt-transport-https ca-certificates curl gnupg-agent software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
apt-get update && apt-get install -y docker-ce docker-ce-cli containerd.io

# Install nfs-utils
apt-get update && apt-get install -y nfs-common

# Install kubectl, kubeadm, kubelet
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF > /etc/apt/sources.list.d/kubernetes.list
    deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y kubelet kubeadm kubectl

# Hold the package version
apt-mark hold kubelet kubeadm kubectl

# Enable and start kubelet service
systemctl enable kubelet
systemctl start kubelet

echo "Install docker/kubelet successfully!"

```

--------------------------------

### Install Kuboard-Spray Docker Image

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-k8s.md

Run this command on a server with Docker installed to deploy Kuboard-Spray. Ensure Docker is installed and has at least 10GB of free disk space. The command maps host directories for data persistence and exposes port 80 for access.

```shell
docker run -d \
  --privileged \
  --restart=unless-stopped \
  --name=kuboard-spray \
  -p 80:80/tcp \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v ~/kuboard-spray-data:/data \
  eipwork/kuboard-spray:latest-amd64
    # 如果抓不到这个镜像，可以尝试一下这个备用地址：
    # swr.cn-east-2.myhuaweicloud.com/kuboard/kuboard-spray:latest-amd64
```

--------------------------------

### Quick Installation of Kubernetes Components

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubernetes.md

Execute this script on all master and worker nodes to quickly install Docker, nfs-utils, kubectl, kubeadm, and kubelet.

```shell
# Execute on master and worker nodes
curl -sSL https://kuboard.cn/install-script/v1.16.2/install_kubelet.sh | sh
```

--------------------------------

### Install Curl and Test Nginx

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/init-config.md

Inside the container shell, install the curl utility and then send a GET request to localhost to verify that the index.html file written by the init container is being served.

```bash
apt-get update
apt-get install curl
curl localhost
```

--------------------------------

### Access Service via Kuboard Proxy (Curl Example)

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-advanced/proxy/index.md

Copy and execute this command in your terminal to get a response from the proxied service. Useful for API testing.

```shell
curl -k -H "Authorization: Bearer <token>" http://localhost:8080/api/v1/namespaces/example/services/http:web-example:80/proxy/
```

--------------------------------

### Start kubectl proxy

Source: https://github.com/eip-work/kuboard-press/blob/master/guide/proxy/index.md

Execute this command in your terminal to start the kubectl proxy server. Ensure kubectl is configured on your client.

```sh
kubectl proxy
```

--------------------------------

### Install Kuboard Stable Version

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-dashboard.md

Apply the stable version of Kuboard and its metrics server. Ensure you are on the master node if following the Kubernetes installation guide from kuboard.cn.

```sh
kubectl apply -f https://kuboard.cn/install-script/kuboard.yaml
kubectl apply -f https://addons.kuboard.cn/metrics-server/0.3.7/metrics-server.yaml
```

--------------------------------

### Cron Schedule Examples

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/wl-cronjob/run.md

These examples demonstrate different ways to specify a schedule for a CronJob using cron syntax. They include basic minute-based scheduling, hourly scheduling, and using step values for more complex intervals.

```text
0 * * * *
@hourly
0 0,2,4,5,6,8,12,14,16,17,20,22 * * *
0 0-23/2 * * *
0 */2 * * *
```

--------------------------------

### Scale Deployment Example

Source: https://context7.com/eip-work/kuboard-press/llms.txt

Scales a Kubernetes deployment named 'nginx-deployment' to 3 replicas using the kubectl scale command.

```bash
kubectl scale deployment nginx-deployment --replicas=3
```

--------------------------------

### Example kubectl Output

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/config/affinity.md

This sample output shows how pods are distributed across nodes, illustrating the effect of affinity and anti-affinity configurations.

```text
NAME                           READY     STATUS    RESTARTS   AGE       IP           NODE
redis-cache-1450370735-6dzlj   1/1       Running   0          8m        10.192.4.2   kube-node-3
redis-cache-1450370735-j2j96   1/1       Running   0          8m        10.192.2.2   kube-node-1
redis-cache-1450370735-z73mh   1/1       Running   0          8m        10.192.3.1   kube-node-2
web-server-1287567482-5d4dz    1/1       Running   0          7m        10.192.2.3   kube-node-1
web-server-1287567482-6f7v5    1/1       Running   0          7m        10.192.4.3   kube-node-3
web-server-1287567482-s330j    1/1       Running   0          7m        10.192.3.2   kube-node-2
```

--------------------------------

### Start Kuboard v4 with Docker Compose

Source: https://github.com/eip-work/kuboard-press/blob/master/v4/install/quickstart.md

Execute this command in the directory containing your docker-compose.yaml file to start the Kuboard v4 services in detached mode.

```sh
docker compose up -d
```

--------------------------------

### Install Kubectl on Linux

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubectl.md

Installs the kubectl package using yum after the repository has been configured. This command should be run on a Linux client machine.

```bash
yum install -y kubectl
```

--------------------------------

### Example Deployment Annotations

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/obj/annotations.md

Shows practical annotations used in a Kubernetes Deployment, including controller-added revision information and Kuboard-specific display and configuration flags.

```yaml
metadata:
  annotations:
    deployment.kubernetes.io/revision: 7
    k8s.eip.work/displayName: busybox
    k8s.eip.work/ingress: false
    k8s.eip.work/service: none
```

--------------------------------

### Start kubectl Proxy

Source: https://context7.com/eip-work/kuboard-press/llms.txt

Starts the kubectl proxy, which provides a secure way to access Kubernetes services and the API from your local machine.

```bash
# Start kubectl proxy
kubectl proxy
# Starting to serve on 127.0.0.1:8001
```

--------------------------------

### Example Node Description Output

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-bg/architecture/nodes.md

This is an example of the detailed output you might receive when describing a Kubernetes node. It includes labels, annotations, conditions, capacity, allocatable resources, system information, and a list of non-terminated pods.

```yaml
Name:               demo-worker-temp-01
Roles:              <none>
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    kubernetes.io/arch=amd64
                    kubernetes.io/hostname=demo-worker-temp-01
                    kubernetes.io/os=linux
Annotations:        kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock
                    node.alpha.kubernetes.io/ttl: 0
                    projectcalico.org/IPv4Address: 172.172.216.105/20
                    projectcalico.org/IPv4IPIPTunnelAddr: 192.168.199.128
                    volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp:  Mon, 30 Sep 2019 06:30:16 +0800
Taints:             <none>
Unschedulable:      false
Conditions:
  Type                 Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
  ----                 ------  -----------------                 ------------------                ------                       -------
  NetworkUnavailable   False   Wed, 02 Oct 2019 22:37:33 +0800   Wed, 02 Oct 2019 22:37:33 +0800   CalicoIsUp                   Calico is running on this node
  MemoryPressure       False   Sun, 06 Oct 2019 13:44:41 +0800   Mon, 30 Sep 2019 06:30:16 +0800   KubeletHasSufficientMemory   kubelet has sufficient memory available
  DiskPressure         False   Sun, 06 Oct 2019 13:44:41 +0800   Mon, 30 Sep 2019 06:30:16 +0800   KubeletHasNoDiskPressure     kubelet has no disk pressure
  PIDPressure          False   Sun, 06 Oct 2019 13:44:41 +0800   Mon, 30 Sep 2019 06:30:16 +0800   KubeletHasSufficientPID      kubelet has sufficient PID available
  Ready                True    Sun, 06 Oct 2019 13:44:41 +0800   Wed, 02 Oct 2019 22:37:41 +0800   KubeletReady                 kubelet is posting ready status
Addresses:
  InternalIP:  172.172.216.105
  Hostname:    demo-worker-temp-01
Capacity:
 cpu:                2
 ephemeral-storage:  41147472Ki
 hugepages-1Gi:      0
 hugepages-2Mi:      0
 memory:             7733524Ki
 pods:               110
Allocatable:
 cpu:                2
 ephemeral-storage:  37921510133
 hugepages-1Gi:      0
 hugepages-2Mi:      0
 memory:             7631124Ki
 pods:               110
System Info:
 Machine ID:                 20190711105006363114529432776998
 System UUID:                841EC123-F92C-4A3A-BEC0-DAADDD625067
 Boot ID:                    70c08b02-45ed-456f-8deb-b5c0ebeab414
 Kernel Version:             3.10.0-957.21.3.el7.x86_64
 OS Image:                   CentOS Linux 7 (Core)
 Operating System:           linux
 Architecture:               amd64
 Container Runtime Version:  docker://18.9.7
 Kubelet Version:            v1.16.0
 Kube-Proxy Version:         v1.16.0
Non-terminated Pods:         (21 in total)
  Namespace                  Name                                        CPU Requests  CPU Limits  Memory Requests  Memory Limits  AGE
  ---------                  ----                                        ------------  ----------  ---------------  -------------  ---
  default                    nginx-deployment-5754944d6c-8lnlx           0 (0%)        0 (0%)      0 (0%)           0 (0%)         3d14h
  example                    gateway-example-6f6f45cd6-mhggv             0 (0%)        0 (0%)      0 (0%)           0 (0%)         3d14h
  example                    monitor-grafana-ff99b5b6f-sxppz             0 (0%)        0 (0%)      0 (0%)           0 (0%)         3d14h
  kube-system                calico-node-qjfqd                           250m (12%)    0 (0%)      0 (0%)           0 (0%)         6d7h
  kube-system                eip-nfs-cluster-storage-6c9c7d46f4-lmxql    0 (0%)        0 (0%)      0 (0%)           0 (0%)         3d14h
  kube-system                kube-proxy-4xz9h                            0 (0%)        0 (0%)      0 (0%)           0 (0%)         3d15h
  kube-system                monitor-prometheus-node-exporter-t7d24      0 (0%)        0 (0%)      0 (0%)           0 (0%)         2d20h
  kuboard-blog               cloud-busybox-867645c5dd-7l97b              0 (0%)        0 (0%)      0 (0%)           0 (0%)         3d14h
  kuboard-blog               db-wordpress-79d88d66b7-j7kj8               0 (0%)        0 (0%)      0 (0%)           0 (0%)         3d14h
  kuboard-press              svc-busybox-6cc877b848-2kl28                0 (0%)        0 (0%)      0 (0%)           0 (0%)         3d14h
  kuboard-press              web-kuboard-press-6d6f8bdbb8-c4q44          0 (0%)        0 (0%)      0 (0%)           0 (0%)         2d3h
  nginx-ingress              nginx-ingress-hsv26                         0 (0%)        0 (0%)      0 (0%)           0 (0%)         6d7h
```

--------------------------------

### Get StatefulSets and Services by Namespace

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/obj/field.md

This command demonstrates selecting multiple resource types (StatefulSets and Services) across all namespaces, filtering by those not in the 'default' namespace.

```sh
kubectl get statefulsets,services --all-namespaces --field-selector metadata.namespace!=default
```

--------------------------------

### Kubectl Context Configuration Example

Source: https://github.com/eip-work/kuboard-press/blob/master/install/config-kubectl.md

This YAML snippet shows an example of a kubeconfig file defining multiple contexts, each specifying a cluster, namespace, and user. The 'current-context' field indicates the active configuration.

```yaml
contexts:
- context:
    cluster: development
    namespace: frontend
    user: developer
  name: dev-frontend
- context:
    cluster: development
    namespace: ramp
    user: developer
  name: dev-ramp-up
- context:
    cluster: development
    namespace: storage
    user: developer
  name: dev-storage
- context:
    cluster: scratch
    namespace: default
    user: experimenter
  name: exp-scratch
current-context: dev-frontend
kind: Config
users:
...
```

--------------------------------

### Get Kubernetes Resource Lists with kubectl

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-basics/explore.md

Use `kubectl get` to list resources like Deployments, Pods, and Nodes. Add `-A` or `--all-namespaces` to see all namespaces, or `-n <namespace>` for a specific one.

```bash
# kubectl get 资源类型

#获取类型为Deployment的资源列表
kubectl get deployments

#获取类型为Pod的资源列表
kubectl get pods

#获取类型为Node的资源列表
kubectl get nodes
```

```bash
# 查看所有名称空间的 Deployment
kubectl get deployments -A
kubectl get deployments --all-namespaces
# 查看 kube-system 名称空间的 Deployment
kubectl get deployments -n kube-system
```

--------------------------------

### Describe Kubernetes Resources with kubectl

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-basics/explore.md

Use `kubectl describe` to get detailed information about a specific resource, such as a Pod or Deployment.

```bash
# kubectl describe 资源类型 资源名称

#查看名称为nginx-XXXXXX的Pod的信息
kubectl describe pod nginx-XXXXXX	

#查看名称为nginx的Deployment的信息
kubectl describe deployment nginx
```

--------------------------------

### Verify kubectl Installation

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubectl.md

Execute these commands to verify that kubectl is correctly configured and can communicate with the Kubernetes cluster.

```shell
kubectl get nodes
```

```shell
kubectl get pods -n kube-system
```

--------------------------------

### Pod with an Annotation Example

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/obj/annotations.md

Demonstrates how to add a simple annotation, `imageregistry`, to a Pod's metadata to store information like an image registry URL.

```yaml
apiVersion: v1
kind: Pod
metadata:
  name: annotations-demo
  annotations:
    imageregistry: "https://hub.docker.com/"
spec:
  containers:
  - name: nginx
    image: nginx:1.7.9
    ports:
    - containerPort: 80
```

--------------------------------

### Quick Master Node Initialization (Shell)

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubernetes.md

Execute this script on the first master node to quickly initialize it. Ensure APISERVER_NAME and POD_SUBNET are set correctly and the DNS entry is added to /etc/hosts.

```shell
# Only execute on the first master node
# Replace apiserver.demo with your desired dnsName
export APISERVER_NAME=apiserver.demo
# The network segment for Kubernetes pods, created by Kubernetes after installation, does not exist in your physical network beforehand
export POD_SUBNET=10.100.0.1/16
echo "127.0.0.1    ${APISERVER_NAME}" >> /etc/hosts
curl -sSL https://kuboard.cn/install-script/v1.16.2/init_master.sh | sh
```

--------------------------------

### Manual Master Node Initialization Setup (Shell)

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubernetes.md

This script sets up environment variables and the hosts file for manual master node initialization. The actual initialization script (init_master.sh) needs to be executed separately.

```shell
# Only execute on the first master node
# Replace apiserver.demo with your desired dnsName
export APISERVER_NAME=apiserver.demo
# The network segment for Kubernetes pods, created by Kubernetes after installation, does not exist in your physical network beforehand
export POD_SUBNET=10.100.0.1/16
echo "127.0.0.1    ${APISERVER_NAME}" >> /etc/hosts
```

--------------------------------

### Create kubectl Configuration File (Windows)

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubectl.md

Create a '.kube/config' file in the user's home directory using a text editor. Paste the content from '/etc/kubernetes/admin.conf' into this file and save it.

```text
Create file ~/.kube/config
```

--------------------------------

### Viewing Pod's resolv.conf (IPv4)

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/service/dns.md

Executes a command within the 'dns-example' Pod to display the contents of its `/etc/resolv.conf` file, reflecting the custom DNS configuration. This example assumes an IPv4 environment.

```bash
kubectl exec -it dns-example -- cat /etc/resolv.conf
```

--------------------------------

### Kubernetes Readiness Probe Configuration

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-practice/micro-service/design-pattern.md

Configure a readiness probe for a container to ensure it only receives traffic when it is ready to serve requests. This example uses an HTTP GET request.

```yaml
readinessProbe:
  httpGet:
    path: /
    port: 5000
  timeoutSeconds: 1
  periodSeconds: 5
```

--------------------------------

### Kubernetes HTTPGet Probe Example

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/pod-health.md

This Liveness probe uses an HTTP GET request to check the health of an application. It specifies the path, port, and optionally headers for the request.

```yaml
livenessProbe:
  httpGet:
    path: /health
    port: 8080
    httpHeaders:
    - name: Custom-Header
      value: Awesome
```

--------------------------------

### Get Busyboxplus Container Terminal

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/service/connecting.md

Launches an interactive busyboxplus container with curl installed, allowing you to test DNS resolution and network connectivity within the cluster. Press Enter for the command prompt.

```bash
kubectl run curl --image=radial/busyboxplus:curl -i --tty
```

--------------------------------

### Verify Kubectl Installation on Linux

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubectl.md

Checks the installed kubectl version to confirm a successful installation on a Linux system. This is a standard verification step.

```bash
kubectl version
```

--------------------------------

### Get Pod Names for a Service

Source: https://github.com/eip-work/kuboard-press/blob/master/t/cka/daily/011.md

This command retrieves only the names of pods associated with a specific service. It first uses `kubectl get service` to find the service's labels and then `kubectl get pod` with a custom output format to extract pod names.

```bash
kubectl get pods "-o=custom-columns=NAME:.metadata.name"
```

--------------------------------

### Create Deployment with Multiple Labels

Source: https://github.com/eip-work/kuboard-press/blob/master/t/cka/daily/011.md

This command demonstrates creating a deployment with multiple labels applied. It's a variation of the initial deployment creation, showcasing how to assign several key-value pairs to a Pod.

```bash
kubectl run cka-1203-03   --image=nginx --labels="a=a,b=b"
deployment.apps/cka-1203-03 created
```

--------------------------------

### Dockerfile for Building an Executable

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-practice/micro-service/design-pattern.md

This Dockerfile example demonstrates a common anti-pattern where build tools and source code are included in the final image, increasing its size and posing security risks. Consider using multi-stage builds to avoid this.

```dockerfile
FROM ubuntu:14.04

RUN apt-get update
RUN apt-get install gcc
RUN gcc hello.c -o /hello
```

--------------------------------

### Register Pod with Management Service

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/init-container.md

This example shows how an init container can register the Pod with a management service using its name and IP address. Ensure the management service host and port are correctly set.

```sh
curl -X POST http://$MANAGEMENT_SERVICE_HOST:$MANAGEMENT_SERVICE_PORT/register -d 'instance=$(<POD_NAME>)&ip=$(<POD_IP>)'
```

--------------------------------

### Install Rook Ceph Cluster

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/persistent/ceph/rook-config.md

Execute these commands sequentially to install the Rook Ceph cluster. Ensure you have kubectl configured for your Kubernetes cluster.

```sh
kubectl create -f https://kuboard.cn/statics/learning/ceph/rook-1.5.4/crds.yaml
kubectl create -f https://kuboard.cn/statics/learning/ceph/rook-1.5.4/common.yaml
kubectl create -f https://kuboard.cn/statics/learning/ceph/rook-1.5.4/operator.yaml
kubectl create -f https://kuboard.cn/statics/learning/ceph/rook-1.5.4/cluster.yaml
```

--------------------------------

### Create Kuboard Database for OpenGauss

Source: https://github.com/eip-work/kuboard-press/blob/master/v4/install/index.md

This script sets up the Kuboard database and user within an OpenGauss instance. It specifies UTF8 encoding and PG compatibility.

```sql
CREATE USER kuboard PASSWORD 'Kuboard123';
CREATE DATABASE kuboard OWNER=kuboard ENCODING='UTF8' DBCOMPATIBILITY='PG';
\c kuboard
CREATE SCHEMA kuboard AUTHORIZATION kuboard;
```

--------------------------------

### Create and Use a Namespace with kubectl

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/obj/namespaces.md

These commands demonstrate how to create a new namespace and then deploy a pod within that specific namespace. Replace '<your-namespace>' with the desired namespace name.

```bash
kubectl run nginx --image=nginx --namespace=<your-namespace>
kubectl get pods --namespace=<your-namespace>
```

--------------------------------

### ReplicaSet Pod Selector Example

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/wl-replicaset/index.md

Example of a label selector used by a ReplicaSet to identify Pods it should manage. Ensure `.spec.template.metadata.labels` matches this selector.

```yaml
matchLabels:
  tier: frontend
```

--------------------------------

### 套件描述文件示例 (addon.json)

Source: https://github.com/eip-work/kuboard-press/blob/master/guide/addon/customize.md

此JSON文件定义了套件的基本信息、脚本、Kubernetes资源和附加文件。确保脚本和k8s文件的路径相对于此文件是正确的。

```json
{
  "name": "资源层监控套件",
  "id": "eip-monitor-system",
  "version": "0.1.1",
  "lastUpdate": "2019-12-11",
  "maintainer": "shaohq@foxmail.com",
  "scripts": ["system-addon.js"],
  "k8s": ["system-k8s.yaml"],
  "resources": ["resource/1621.json", "resource/1860.json", "resource/3146.json", "resource/8588.json"],
  "isGlobal": true,
  "info": {
    "description": "通过prometheus/grafana监控Kubernetes资源层的信息，包括CPU使用、内存使用、网络使用等信息。",
    "document": "https://github.com/eip-work/kuboard-addons/tree/master/repository/eip-monitor-system/0.1.1"
  }
}
```

--------------------------------

### User Impersonation Request Headers Example

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-advanced/sec/authenticate/readme.md

Example of HTTP request headers used for user impersonation, including user, group, and extra fields.

```text
Impersonate-User: jane.doe@example.com
Impersonate-Group: developers
Impersonate-Group: admins
Impersonate-Extra-dn: cn=jane,ou=engineers,dc=example,dc=com
Impersonate-Extra-acme.com%2Fproject: some-project
Impersonate-Extra-scopes: view
Impersonate-Extra-scopes: development
```

--------------------------------

### Configure Hosts File (Linux/macOS)

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubectl.md

Append an entry to the '/etc/hosts' file to map an IP address to a hostname. Replace 'x.x.x.x' with the actual IP address of the demo-master-a-1 and 'apiserver.demo' with the host from the cluster server URL.

```shell
echo "x.x.x.x    apiserver.demo" >> /etc/hosts
```

--------------------------------

### Delete Existing Calico Installation

Source: https://github.com/eip-work/kuboard-press/blob/master/install/upgrade-k8s/calico-3.8-3.9.md

Remove the current Calico installation if the version is 3.8.2 or 3.8.x. Ensure you use the correct YAML file corresponding to your version.

```sh
# 如果版本号是 v3.8.2 或者 v3.8.x，则删除命令如下
kubectl delete -f https://kuboard.cn/install-script/calico/calico-3.8.yaml
```

--------------------------------

### Kubernetes 控制器伪代码

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/service/network.md

此伪代码展示了 Kubernetes 控制器的工作循环：不断监控当前状态并与期望状态进行比较，然后采取行动以缩小差距。

```go
while true:
  X = currentState()
  Y = desiredState()

  if X == Y:
    return  # Do nothing
  else:
    do(tasks to get to Y)
```

--------------------------------

### Get Deployments using kubectl

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-basics/deploy-app.md

Check the status and details of your Kubernetes Deployments using the kubectl get deployments command. This helps verify if the deployment was successful.

```sh
kubectl get deployments
```

--------------------------------

### Pod Owner References Example

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/gc.md

This is an example output showing the ownerReferences field for a Pod created by a ReplicaSet. It indicates the Pod's owner is a ReplicaSet named 'my-repset'.

```yaml
apiVersion: v1
kind: Pod
metadata:
  ...
  ownerReferences:
  - apiVersion: apps/v1
    controller: true
    blockOwnerDeletion: true
    kind: ReplicaSet
    name: my-repset
    uid: d9607e19-f88f-11e6-a518-42010a800195
  ...
```

--------------------------------

### Container Process Information

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/config/sec-ctx/con.md

Example output showing processes running within a container. Note that the 'USER' column reflects the runAsUser setting (2000 in this case), overriding the Pod's setting (1000).

```text
PID   USER      TIME  COMMAND
  1   2000      0:00  sleep 1h
    6   2000      0:00  sh
   11   2000      0:00  ps aux
...
```

--------------------------------

### Display Resource Kind with Output

Source: https://github.com/eip-work/kuboard-press/blob/master/t/cka/daily/011.md

This command shows the resource type (e.g., `deployment.extensions`) along with the deployment details. It's useful when dealing with multiple resource types or to explicitly see the kind of object being listed.

```bash
kubectl get deployments. --show-kind
```

--------------------------------

### Install Rook-Ceph Cluster

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/persistent/ceph/rook-config-1.4.7.md

Apply the common, operator, and cluster YAML files to install Rook-Ceph. Consider using docker-image-loader for faster image deployment, especially in air-gapped environments.

```sh
kubectl create -f https://kuboard.cn/statics/learning/ceph/rook-1.4.7/common.yaml
kubectl create -f https://kuboard.cn/statics/learning/ceph/rook-1.4.7/operator.yaml
kubectl create -f https://kuboard.cn/statics/learning/ceph/rook-1.4.7/cluster.yaml
```

--------------------------------

### Check Master Initialization Status (Shell)

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubernetes.md

Execute these commands on the first master node to monitor the status of system pods and verify node readiness after initialization. Wait until all pods are in a Running state.

```shell
# Only execute on the first master node

# Execute the following command and wait for 3-10 minutes until all pods are in the Running state
watch kubectl get pod -n kube-system -o wide

# View the master node initialization results
kubectl get nodes
```

--------------------------------

### Configure Yum Repository for Kubectl on Linux

Source: https://github.com/eip-work/kuboard-press/blob/master/install/install-kubectl.md

Sets up the necessary YUM repository configuration for installing kubectl on RHEL-based Linux distributions. Ensure this configuration is correctly applied before proceeding with the installation.

```bash
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
       http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
```

--------------------------------

### Get ReplicaSet Information with kubectl

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/wl-deployment/pause.md

Use `kubectl get rs` to list ReplicaSets associated with your Deployments. This is useful for observing the state of pods managed by different ReplicaSet versions during a rollout.

```bash
kubectl get rs
```

--------------------------------

### Build and Push Docker Image (Shell Script)

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-practice/ocp/back-center.md

These commands guide you through building the Docker image for the back-center application and pushing it to a Docker registry. Ensure you are in the back-center directory and logged into your Docker account.

```shell
# 切换到 back-center 目录
cd /root/open-capacity-platform/web-portal/back-center
# 使用你自己的 docker 用户名登录
docker login
# 构建镜像
docker build -t ocpsample/back-center:latest .
# 推送镜像
docker push ocpsample/back-center:latest
```

--------------------------------

### Get Deployment Information with kubectl

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/wl-deployment/pause.md

Use `kubectl get deployment` to view the current status of your Deployments. This command helps in verifying the desired, current, up-to-date, and available replica counts.

```bash
kubectl get deployment
```

--------------------------------

### lsblk -f Output Example

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/persistent/ceph/rook-config.md

Example output of `lsblk -f` showing disk information. The `vdb` disk is available for Ceph OSDs as its FSTYPE is empty, while `vda` and its partitions are already formatted.

```sh
lsblk -f
NAME                  FSTYPE      LABEL UUID                                   MOUNTPOINT
vda
└─vda1                LVM2_member       eSO50t-GkUV-YKTH-WsGq-hNJY-eKNf-3i07IB
  ├─ubuntu--vg-root   ext4              c2366f76-6e21-4f10-a8f3-6776212e2fe4   /
  └─ubuntu--vg-swap_1 swap              9492a3dc-ad75-47cd-9596-678e8cf17ff9   [SWAP]
vdb
```

--------------------------------

### Delay Pod Startup

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-intermediate/workload/init-container.md

A simple init container command to introduce a fixed delay before application containers start. Useful for scenarios requiring a timed startup sequence.

```sh
sleep 60
```

--------------------------------

### Describe Ingress for Configuration Details

Source: https://github.com/eip-work/kuboard-press/blob/master/learning/k8s-advanced/ts/deployment.md

This command displays the configuration details of an Ingress resource, including its backend services, which is useful for debugging Ingress setup.

```bash
kubectl describe ingress <ingress-name>
```