kubectl和yaml文件内容介绍 Day02

1. kubectl使用

官方文档：
https://kubernetes.io/zh-cn/docs/reference/kubectl/
https://kubernetes.io/zh-cn/docs/reference/kubectl/cheatsheet/
https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#get

1. 常用命令

2. 基础命令

2.1 explain

当我们不知道如何管理一个资源（yaml）的时候，可以通过这个参数获取帮助

[root@k8s-harbor01 ~]# kubectl explain po # 这里会显示，关于pod的yaml该怎么写
KIND:     Pod
VERSION:  v1

DESCRIPTION:
     Pod is a collection of containers that can run on a host. This resource is
     created by clients and scheduled onto hosts.

FIELDS:
   apiVersion   <string>
     APIVersion defines the versioned schema of this representation of an
     object. Servers should convert recognized schemas to the latest internal
     value, and may reject unrecognized values. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources

   kind <string>
     Kind is a string value representing the REST resource this object
     represents. Servers may infer this from the endpoint the client submits
     requests to. Cannot be updated. In CamelCase. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds

   metadata     <Object>
     Standard object's metadata. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata

   spec <Object>
     Specification of the desired behavior of the pod. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status

   status       <Object>
     Most recently observed status of the pod. This data may not be up to date.
     Populated by the system. Read-only. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status


# 并且，当我们写到某一个阶段的时候，不知道有些什么参数，也可以用explain查
[root@k8s-harbor01 ~]# kubectl explain po.spec.volumes
KIND:     Pod
VERSION:  v1

RESOURCE: volumes <[]Object>
…………省略部分内容

# yaml中是有缩进和上下级关系的，上面的explain换成yaml就是这样
sepc:
  volumes:

2.2 使用explain创建一个ns

开两个窗口，一个查，一个写yaml

2.2.1 查ns怎么创建

[root@k8s-harbor01 ~]# kubectl explain ns # 下面查出来的值，都是最顶级的，不用缩进
KIND:     Namespace
VERSION:  v1

DESCRIPTION:
     Namespace provides a scope for Names. Use of multiple namespaces is
     optional.

FIELDS:
   apiVersion   <string>
     APIVersion defines the versioned schema of this representation of an
     object. Servers should convert recognized schemas to the latest internal
     value, and may reject unrecognized values. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources

   kind <string>
     Kind is a string value representing the REST resource this object
     represents. Servers may infer this from the endpoint the client submits
     requests to. Cannot be updated. In CamelCase. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds

   metadata     <Object>
     Standard object's metadata. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata

   spec <Object>
     Spec defines the behavior of the Namespace. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status

   status       <Object>
     Status describes the current status of a Namespace. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status

2.2.2 写

[root@k8s-harbor01 yaml]# vim ns-myserver.yaml
apiVersion: v1
kind: # 这里不知道类型有些什么，就继续通过explain查

2.2.3 查ns的kind类型

[root@k8s-harbor01 ~]# kubectl explain ns.kind
KIND:     Namespace # 这里就是我们要写的类型
VERSION:  v1

FIELD:    kind <string>

DESCRIPTION:
     Kind is a string value representing the REST resource this object
     represents. Servers may infer this from the endpoint the client submits
     requests to. Cannot be updated. In CamelCase. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds

2.2.4 写

[root@k8s-harbor01 yaml]# cat ns-myserver.yaml # 如果没有其他去求，这个创建ns的yaml就已经写完了
apiVersion: v1
kind: Namespace

2.2.5 查怎么写ns的名称

名称、端口等都属于元数据，所以要查metadata字段

[root@k8s-harbor01 ~]# [root@k8s-harbor01 ~]# kubectl explain ns.metadata|grep name # 内容太多 过滤下
   name <string>
     Name must be unique within a namespace. Is required when creating
     generation of an appropriate name automatically. Name is primarily intended
     More info: http://kubernetes.io/docs/user-guide/identifiers#names

2.2.6 写

[root@k8s-harbor01 yaml]# cat ns-myserver.yaml # 如果没有其他去求，这个创建ns的yaml就已经写完了
apiVersion: v1
kind: Namespace
metadata:
  name: myserver

2.2.7 创建

[root@k8s-harbor01 yaml]# kubectl apply -f ns-myserver.yaml 
namespace/myserver created
[root@k8s-harbor01 yaml]# kubectl get ns |grep myserver
myserver          Active   6s

2.3 get 显示一个或多个资源

2.3.1 get 作用

查询集群中的各种资源信息
[root@k8s-harbor01 yaml]# kubectl get --help # 获取帮助

2.3.2 查看deployment类型的控制器

其他资源类型的查看方式基本也都一样

[root@k8s-harbor01 yaml]# kubectl get deploy  # 默认查看default名称空间下的资源
No resources found in default namespace.

[root@k8s-harbor01 yaml]# kubectl get deploy -A  # -A表示查看所有名称空间下的资源
NAMESPACE     NAME                      READY   UP-TO-DATE   AVAILABLE   AGE
kube-system   calico-kube-controllers   1/1     1            1           18h
kube-system   coredns                   2/2     2            2           18h

[root@k8s-harbor01 yaml]# kubectl get deploy -n kube-system # -n 查看指定名称空间下的资源
NAME                      READY   UP-TO-DATE   AVAILABLE   AGE
calico-kube-controllers   1/1     1            1           18h
coredns                   2/2     2            2           18h

2.3.3 json格式输出

这种方式不易读，但是方便脚本处理

[root@k8s-harbor01 yaml]# kubectl get deploy -o -n kube-system # 这种方式会输出指定名称空间下的所有内容

[root@k8s-harbor01 yaml]# kubectl get deploy -n kube-system coredns -o json # 可以通过这种方式查看某一个资源

2.3.4 yaml格式输出

[root@k8s-harbor01 yaml]# kubectl get deploy -n kube-system coredns -o yaml

2.4 查看node

node是全局资源，不受ns限制

[root@k8s-harbor01 yaml]# kubectl get no # 查看方式大同小异，可以查看单独一个，也可以输出json和yaml格式
NAME           STATUS                     ROLES    AGE   VERSION
k8s-master01   Ready,SchedulingDisabled   master   18h   v1.26.1
k8s-master02   Ready,SchedulingDisabled   master   18h   v1.26.1
k8s-master03   Ready,SchedulingDisabled   master   18h   v1.26.1
k8s-node01     Ready                      node     18h   v1.26.1
k8s-node02     Ready                      node     18h   v1.26.1
k8s-node03     Ready                      node     18h   v1.26.1

2.5 describe 显示特定资源或资源组的详细信息

2.5.1 查看pod事件

其他资源类型操作也一样的

[root@k8s-harbor01 yaml]# kubectl describe po net-test3
…………省略部分内容
Events:  # 这个东西很重要，会显示一定时间内的pod事件，正常的不正常的都会记录，主要看 Message这一列
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  7s    default-scheduler  Successfully assigned default/net-test3 to k8s-node02
  Normal  Pulled     6s    kubelet            Container image "10.31.200.104/myserver/centos:7.9.2009" already present on machine
  Normal  Created    6s    kubelet            Created container net-test3
  Normal  Started    6s    kubelet            Started container net-test3

2.5.2 查看node详情

[root@k8s-harbor01 yaml]# kubectl describe no k8s-node03
# 下面列举的都是一下日常工作中关注的比较多的东西
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    kubernetes.io/arch=amd64
                    kubernetes.io/hostname=k8s-node03
                    kubernetes.io/os=linux
                    kubernetes.io/role=node
Taints:             <none>

  Namespace                   Name                        CPU Requests  CPU Limits  Memory Requests  Memory Limits  Age
  ---------                   ----                        ------------  ----------  ---------------  -------------  ---
  default                     net-test1                   0 (0%)        0 (0%)      0 (0%)           0 (0%)         19h
  kube-system                 calico-node-bcpqf           250m (12%)    0 (0%)      0 (0%)           0 (0%)         19h
  kube-system                 coredns-5879bb4b8c-g8z8b    100m (5%)     200m (10%)  70Mi (1%)        256Mi (7%)     19h
Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  Resource           Requests    Limits 
  --------           --------    ------
  cpu                350m (17%)  200m (10%)
  memory             70Mi (1%)   256Mi (7%)
  ephemeral-storage  0 (0%)      0 (0%)
  hugepages-1Gi      0 (0%)      0 (0%)
  hugepages-2Mi      0 (0%)      0 (0%)
Events:              <none>

2.6 logs 查看容器日志

logs只能看到标准输出和错误输出（/dev/stdout、/dev/stderr），非这两种类型的，只能进入容器查看

如官方的nginx：dockerfile中就有，ln -sf /dev/stdout /var/log/access.log、ln -sf /dev/stderr /var/log/error.log

2.6.1 查看所有日志

不推荐这种方式，pod日志太多，会直接卡死终端

[root@k8s-harbor01 yaml]# kubectl logs -n kube-system calico-node-bcpqf

2.6.2 实时查看日志

这个也不推荐

[root@k8s-harbor01 yaml]# kubectl logs -f -n kube-system calico-node-bcpqf

2.6.3 实时查看最后几行日志

这种方式还可以

[root@k8s-harbor01 yaml]# kubectl logs -f --tail 100  -n kube-system calico-node-bcpqf

2.6.4 分页查看所有日志

这种方式还可以

[root@k8s-harbor01 yaml]# kubectl logs -n kube-system calico-node-bcpqf | less

2.7 exec 在某个容器中执行一个命令

2.7.1 执行命令

[root@k8s-harbor01 ~]# kubectl exec  net-test2 -- cat /etc/hosts
# Kubernetes-managed hosts file.
127.0.0.1       localhost
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
fe00::0 ip6-mcastprefix
fe00::1 ip6-allnodes
fe00::2 ip6-allrouters
10.200.85.195   net-test2

2.7.2 进入pod

[root@k8s-harbor01 ~]# kubectl exec -it  net-test2 -- /bin/bash

2.8 delete 按文件名、标准输入、资源和名称或按资源和标签选择器删除资源

kubectl delete -f app.yaml
kubectl delete $资源名称

3. 配置命令

3.1 create 从文件或标准输入创建资源

工作中不常用，更推荐apply

kucectl create -f app.yaml

3.2 apply 通过文件名或标准输入将配置应用于资源

支持从yaml或json格式文件、标准输入、或指定URL创建资源对象

kucectl apply -f app.yaml
kucectl apply -f https://xxx.yaml

kucectl apply -k dir/ # 执行指定目录下的所有yaml

3.3 create和apply的区别

create属于对资源对象的全量操作，而apply属于增量。
比如说：
首次应用一个yaml文件，create和apply都可以，但是用create二次执行就会报错：资源已存在。
apply反复执行都没有问题，因为它只会加载发生变化的部分。

4. 集群管理命令

4.1 cluster-info 显示集群信息

[root@k8s-harbor01 ~]# kubectl cluster-info 
Kubernetes control plane is running at https://10.31.200.100:6443
CoreDNS is running at https://10.31.200.100:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

4.2 cordon 标记节点为不可调度

[root@k8s-harbor01 ~]# kubectl get no
NAME           STATUS                     ROLES    AGE   VERSION
k8s-master01   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-master02   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-master03   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-node01     Ready                      node     43h   v1.26.1
k8s-node02     Ready                      node     43h   v1.26.1
k8s-node03     Ready                      node     43h   v1.26.1
[root@k8s-harbor01 ~]# kubectl cordon k8s-node01
node/k8s-node01 cordoned
[root@k8s-harbor01 ~]# kubectl get no
NAME           STATUS                     ROLES    AGE   VERSION
k8s-master01   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-master02   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-master03   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-node01     Ready,SchedulingDisabled   node     43h   v1.26.1 # 这样就关闭调度了
k8s-node02     Ready                      node     43h   v1.26.1
k8s-node03     Ready                      node     43h   v1.26.1

4.4 uncordon 标记节点为可调度

一般是配合上面的命令使用

[root@k8s-harbor01 ~]# kubectl uncordon k8s-node01
node/k8s-node01 uncordoned
[root@k8s-harbor01 ~]# kubectl get no
NAME           STATUS                     ROLES    AGE   VERSION
k8s-master01   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-master02   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-master03   Ready,SchedulingDisabled   master   43h   v1.26.1
k8s-node01     Ready                      node     43h   v1.26.1 # 这样就又可以调度了
k8s-node02     Ready                      node     43h   v1.26.1
k8s-node03     Ready                      node     43h   v1.26.1

4.5 drain 驱逐节点上的pod

使用场景：清空节点，准备维护。该命令驱逐pod的同时，还会关闭节点调度。
注意：不能驱逐没有控制器的资源（如单纯的pod）和daemonset控制器管理的pod，除非添加参数

[root@k8s-harbor01 ~]# kubectl cordon k8s-node01 # 关闭node01的调度
node/k8s-node01 cordoned

[root@k8s-harbor01 ~]# kubectl get po -o wide -A |grep node01 # 可以看到有3个pod运行在node01上
default       net-test2                                 1/1     Running   0          43h   10.200.85.195    k8s-node01     <none>           <none>
kube-system   calico-node-cf7xm                         1/1     Running   0          43h   10.31.200.110    k8s-node01     <none>           <none>
kube-system   coredns-5879bb4b8c-tjhhk                  1/1     Running   0          43h   10.200.85.194    k8s-node01     <none>           <none>

[root@k8s-harbor01 ~]# kubectl drain k8s-node01 # 驱逐node01上的pod
node/k8s-node01 already cordoned
error: unable to drain node "k8s-node01" due to error:[cannot delete Pods declare no controller (use --force to override): default/net-test2, cannot delete DaemonSet-managed Pods (use --ignore-daemonsets to ignore): kube-system/calico-node-cf7xm], continuing command...
There are pending nodes to be drained:
 k8s-node01
cannot delete Pods declare no controller (use --force to override): default/net-test2
cannot delete DaemonSet-managed Pods (use --ignore-daemonsets to ignore): kube-system/calico-node-cf7xm

[root@k8s-harbor01 ~]# kubectl drain k8s-node01  --force --ignore-daemonsets
node/k8s-node01 already cordoned
Warning: deleting Pods that declare no controller: default/net-test2; ignoring DaemonSet-managed Pods: kube-system/calico-node-cf7xm
evicting pod kube-system/coredns-5879bb4b8c-tjhhk
evicting pod default/net-test2
pod/coredns-5879bb4b8c-tjhhk evicted
pod/net-test2 evicted
node/k8s-node01 drained

[root@k8s-harbor01 ~]# kubectl get po -o wide -A |grep node01 # 这样就只剩一个calico pod了
kube-system   calico-node-cf7xm                         1/1     Running   0          43h   10.31.200.110    k8s-node01     <none>           <no

4.6 taint 更新一个或者多个节点上的污点

主要是实现pod亲和性和反亲和性的
这个后面讲

[root@k8s-harbor01 ~]# kubectl taint --help

4.7 api-resources 打印服务器上支持的API资源

就是显示各种资源类型，简称、支持的apiversion版本以及各资源类型的简写。

[root@k8s-harbor01 ~]# kubectl api-resources |grep 'deployments'
NAME                              SHORTNAMES   APIVERSION                             NAMESPACED   KIND
deployments                       deploy       apps/v1                                true         Deployment

4.8 api-versions 只显示api版本

还是上面的更加适用

[root@k8s-harbor01 ~]# kubectl api-versions
admissionregistration.k8s.io/v1
apiextensions.k8s.io/v1
apiregistration.k8s.io/v1
apps/v1
authentication.k8s.io/v1
authorization.k8s.io/v1
autoscaling/v1
autoscaling/v2
batch/v1
certificates.k8s.io/v1
coordination.k8s.io/v1
discovery.k8s.io/v1
events.k8s.io/v1
flowcontrol.apiserver.k8s.io/v1beta2
flowcontrol.apiserver.k8s.io/v1beta3
networking.k8s.io/v1
node.k8s.io/v1
policy/v1
rbac.authorization.k8s.io/v1
scheduling.k8s.io/v1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1

4.9 version 输出客户端和服务端的版本信息

[root@k8s-harbor01 ~]# kubectl version --short
Flag --short has been deprecated, and will be removed in the future. The --short output will become the default.
Client Version: v1.26.1
Kustomize Version: v4.5.7
Server Version: v1.26.1

[root@k8s-harbor01 ~]# kubectl version --output=yaml
clientVersion:
  buildDate: "2023-01-18T15:58:16Z"
  compiler: gc
  gitCommit: 8f94681cd294aa8cfd3407b8191f6c70214973a4
  gitTreeState: clean
  gitVersion: v1.26.1
  goVersion: go1.19.5
  major: "1"
  minor: "26"
  platform: linux/amd64
kustomizeVersion: v4.5.7
serverVersion:
  buildDate: "2023-01-18T15:51:25Z"
  compiler: gc
  gitCommit: 8f94681cd294aa8cfd3407b8191f6c70214973a4
  gitTreeState: clean
  gitVersion: v1.26.1
  goVersion: go1.19.5
  major: "1"
  minor: "26"
  platform: linux/amd64

4.10 config 动态修改kubeconfig 文件

[root@k8s-harbor01 ~]# kubectl config
Modify kubeconfig files using subcommands like "kubectl config set current-context my-context"

 The loading order follows these rules:

  1.  If the --kubeconfig flag is set, then only that file is loaded. The flag may only be set once and no merging takes
place.
  2.  If $KUBECONFIG environment variable is set, then it is used as a list of paths (normal path delimiting rules for
your system). These paths are merged. When a value is modified, it is modified in the file that defines the stanza. When
a value is created, it is created in the first file that exists. If no files in the chain exist, then it creates the
last file in the list.
  3.  Otherwise, ${HOME}/.kube/config is used and no merging takes place.

Available Commands:
  current-context   Display the current-context
  delete-cluster    从 kubeconfig 中删除指定的集群
  delete-context    从 kubeconfig 中删除指定的上下文
  delete-user       Delete the specified user from the kubeconfig
  get-clusters      显示在 kubeconfig 中定义的集群
  get-contexts      描述一个或多个上下文
  get-users         Display users defined in the kubeconfig
  rename-context    Rename a context from the kubeconfig file
  set               Set an individual value in a kubeconfig file
  set-cluster       Set a cluster entry in kubeconfig
  set-context       Set a context entry in kubeconfig
  set-credentials   Set a user entry in kubeconfig
  unset             Unset an individual value in a kubeconfig file
  use-context       Set the current-context in a kubeconfig file
  view              显示合并的 kubeconfig 配置或一个指定的 kubeconfig 文件

Usage:
  kubectl config SUBCOMMAND [options]

Use "kubectl  --help" for more information about a given command.
Use "kubectl options" for a list of global command-line options (applies to all commands).

2. yaml

k8s中支持yaml格式的文件应用，也支持json格式的应用，但还是yaml比较常用，因为json可读性太差。

2.1 yaml文件简介

2.1.1 格式

人员名单:
  张三:
  年龄: 18 #
  职业: Linux运维工程师
  爱好: 
    - 看书
    - 学习
    - 加班
  
李四:
  年龄: 20
  职业: Java开发工程师 # 这是职业
  爱好: 
    - 开源技术
    - 微服务
    - 分布式存储

2.1.2 使用注意事项

大小写敏感
使用缩进表示层级关系
缩进时不允许使用Tal键，只允许使用空格
缩进的空格数目不重要，只要相同层级的元素左侧对齐即可
使用”#” 表示注释，从这个字符一直到行尾，都会被解析器忽略
比json更适用于配置文件

2.2 yaml文件示例

2.2.1 deployment文件示例

[root@k8s-harbor01 yaml]# cat nginx.yaml 
apiVersion: apps/v1 # API版本，可以使用kubectl explain Deployment.apiVersion查看适用版本
kind: Deployment # 资源类型
metadata: # deployment控制器的元数据信息，kubectl explain Deployment.metadata
  labels: # deployment控制器的标签，这个一般都是自定义的
    app: myserver-nginx-deployment-label # 这就是自定义的标签（key和value都是自定义），后面会用到
  name: myserver-nginx-deployment # deployment控制器的名称
  namespace: myserver # deployment控制器所在的名称空间，不定义这个字段的话就在默认的名称空间defaule
spec: # 定义deployment中容器的详细信息
  replicas: 1 # 定义deployment的副本数，也就是说可以创建多少个pod，不写默认值为1
  selector: # 标签选择器（Deploy控制器会关联标签为app: myserver-nginx-selector的pod进行管理）
    matchLabels: # 定义匹配的标签，必须要设置
      app: myserver-nginx-selector # 匹配的目标标签
  template: # 定义模板，必须定义，模板是起到描述要创建的pod的作用（pod创建就是根据模板内容来的）
    metadata: # 定义模板元数据
      labels: # 定义模板标签
        app: myserver-nginx-selector # pod标签，该标签被上面的deploy控制器关联，并且svc也是关联这个标签进行访问的
    spec: # 定义pod信息
      containers: # 定义pod中的容器列表，可以多个，最少一个，pod不能动态增减容器
      - name: myserver-nginx-container # 容器名称
        image: 10.31.200.104/myserver/nginx:latest # 容器下载镜像的地址
        imagePullPolicy: IfNotPresent # 镜像拉取策略: IfNotPresent，镜像不存在node节点就拉取。Always，不管镜像在不在，都拉取新的镜像。None，不拉取
        ports: # 定义容器的端口列表（非必须配置，此处作用就算是声明）
        - containerPort: 80 # 定义一个端口
          protocol: TCP # 端口协议。注意：端口协议只支持：SCTP、TCP、UDP
          name: http # 端口名称，不能重复
        - containerPort: 443 # 定义一个端口
          protocol: TCP # 端口协议
          name: https # 端口名称
        env: # 传递环境变量给容器，容器起来后就可以直接调用
        - name: "password" # 变量名称，必须要用引号引起来
          value: "123456" # 变量值
        - name: "age"
          value: "18"
        resources: # 资源请求与限制
          limits: # 资源限制设置，pod能使用的最大资源（上限）
            cpu: 500m # cpu限制，单位为core（核）数，此处为500毫核，可以写0.5或者500m，1000m为1核。该配置不允许低于1m
            memory: 2Gi # 内存限制，单位可以是Mib/Gib/M/B。
          requests: # 资源请求设置（只有node节点上剩余资源满足cpu配置和memory配置，node节点才能被调度过去。）
            # requests建议和limits配置成一样的，避免requests配置过低，容器启动过程中oom(简单点说就是能调度成功，但是容器启动实际需要1G内存，但是调度的时候只请求了512M，所以启动会oom)。
            cpu: 200m # cpu请求数，容器启动的初始可用数量
            memory: 512Mi # 内存请求大小，器启动的初始可用数量，用于调度pod时使用

2.2.2 service yaml文件示例

[root@k8s-harbor01 yaml]# cat nginx-svc.yaml
kind: Service # 定义资源类型为service
apiVersion: v1 # svc 的API版本
metadata: # 定义svc的元数据
  labels: # 定义svc的标签
    app: myserver-nginx # 定义具体的标签名称
  name: myserver-nginx-svc # 定义svc的名称，此名称会被core-dns解析
  namespace: myserver # svc所处的ns，一定要和相关联的pod在同一个ns下
spec: # 定义svc的详细信息
  type: NodePort # 定义svc的类型为NodePort，默认为Clusterip
  ports: # 定义访问端口
  - name: http # 定义一个端口名称
    port: 80 # svc端口
    protocol: TCP # 协议类型
    targetPort: 80 # 目标pod端口
    nodePort: 30001 # node节点暴露的端口.通过nodeport端口访问，会转发到targetPort:
  - name: https # 定义一个端口名称
    port: 443 # svc端口
    protocol: TCP # 协议类型
    targetPort: 443 # 目标pod端口
    nodePort: 30443 # node节点暴露的端口
  selector: # svc标签选择器，关联要访问的目标pod
    app: myserver-nginx-selector # 将流量路由到标签关联的pod上

2.3 应用并测试访问

2.3.1 创建deploy

[root@k8s-harbor01 yaml]# kubectl apply -f nginx.yaml
deployment.apps/myserver-nginx-deployment created
[root@k8s-harbor01 yaml]# kubectl get po -n myserver
NAME                                         READY   STATUS    RESTARTS   AGE
myserver-nginx-deployment-5c9d79c56f-zcj7b   1/1     Running   0          10s

2.3.2 创建svc

root@k8s-harbor01 yaml]# kubectl get po,svc -n myserver
NAME                                             READY   STATUS    RESTARTS   AGE
pod/myserver-nginx-deployment-5c9d79c56f-zcj7b   1/1     Running   0          61s

NAME                         TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
service/myserver-nginx-svc   NodePort   10.100.140.203   <none>        80:30001/TCP,443:30443/TCP   8s

2.3.3 测试访问

[root@k8s-harbor01 yaml]# kubectl get po,svc -n myserver
NAME                                             READY   STATUS    RESTARTS   AGE
pod/myserver-nginx-deployment-5c9d79c56f-zcj7b   1/1     Running   0          23m

NAME                         TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
service/myserver-nginx-svc   NodePort   10.100.140.203   <none>        80:30001/TCP,443:30443/TCP   22m

[root@k8s-master01 ~]# curl -I 10.100.140.203
HTTP/1.1 200 OK
Server: nginx/1.23.4
Date: Thu, 04 May 2023 13:45:18 GMT
Content-Type: text/html
Content-Length: 615
Last-Modified: Tue, 28 Mar 2023 15:01:54 GMT
Connection: keep-alive
ETag: "64230162-267"
Accept-Ranges: bytes