美文网首页
创建deployment、service案例

创建deployment、service案例

作者: jacky_8897 | 来源:发表于2021-05-19 18:31 被阅读0次

创建一个deployment, 此名称为test-httpd, replicas为5， 镜像使用httpd. selector是必须的

spec.selector.matchLabels.app的value必须何metadata.name的值一致
spec.template.metadata.labels.app的value必须何metadata.name的值一致
spec.template.metadata.name的value可以metadata.name的值不一致

test-hpptd.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: test-httpd
spec:
  replicas: 5
  selector:
    matchLabels:
      #这个app的值必须和metadata.name的一样
      app: test-httpd
  template:
    metadata:
      # 这个name的值可以不和metadata.name的一样
      name: test-httpdx
      labels:
        #这个app的值必须和metadata.name的一样
        app: test-httpd
    spec:
      containers:
        - name: httpd
          image: httpd
          ports:
            - containerPort: 80

kubectl apply -f test-httpd.yaml

kubectl get pods
# kubectl get pods
NAME                         READY   STATUS              RESTARTS   AGE
test-httpd-6dd4c6fb76-9bldc   1/1     Running             0          4s
test-httpd-6dd4c6fb76-cfqwc   0/1     ContainerCreating   0          4s
test-httpd-6dd4c6fb76-mrc82   0/1     ContainerCreating   0          4s
test-httpd-6dd4c6fb76-mzzhb   0/1     ContainerCreating   0          4s
test-httpd-6dd4c6fb76-p44v6   0/1     ContainerCreating   0          4s

# get pods -o wide
NAME                         READY   STATUS    RESTARTS   AGE   IP            NODE     NOMINATED NODE   READINESS GATES
test-httpd-6dd4c6fb76-9bldc   1/1     Running   0          68s   10.244.1.17   node01   <none>           <none>
test-httpd-6dd4c6fb76-cfqwc   1/1     Running   0          68s   10.244.1.21   node01   <none>           <none>
test-httpd-6dd4c6fb76-mrc82   1/1     Running   0          68s   10.244.1.20   node01   <none>           <none>
test-httpd-6dd4c6fb76-mzzhb   1/1     Running   0          68s   10.244.1.18   node01   <none>           <none>
test-httpd-6dd4c6fb76-p44v6   1/1     Running   0          68s   10.244.1.19   node01   <none>           <none>

events属于事件提示，它描述了整个资源从开始到现在所经历的全部过程。

Deployment没有像我们想象中直接创建并控制后端的Pod，而是又创建了一个新的资源对象:ReplicaSet(test-httpd-bc546df6f )。
Deployment--> RS(ReplicaSet)--> Pods..

# kubectl describe deployment. test-httpd
Name:                   test-httpd
Namespace:              default
CreationTimestamp:      Wed, 19 May 2021 09:01:13 +0000
Labels:                 <none>
Annotations:            deployment.kubernetes.io/revision: 1
Selector:               app=test-httpd
Replicas:               5 desired | 5 updated | 5 total | 5 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  app=test-httpd
  Containers:
   httpd:
    Image:        httpd
    Port:         80/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   test-httpd-bc546df6f (5/5 replicas created)
Events:
  Type    Reason             Age   From                   Message
  ----    ------             ----  ----                   -------
  Normal  ScalingReplicaSet  3m    deployment-controller  Scaled up replica set test-httpd-6dd4c6fb76 to 5
查看该RS的详细信息，会看到RS整个的Events
kubectl describe rs test-httpd-6dd4c6fb76
Name:           test-httpd-6dd4c6fb76
Namespace:      default
Selector:       app=test-httpd,pod-template-hash=6dd4c6fb76
Labels:         app=test-httpd
                pod-template-hash=6dd4c6fb76
Annotations:    deployment.kubernetes.io/desired-replicas: 5
                deployment.kubernetes.io/max-replicas: 7
                deployment.kubernetes.io/revision: 1
Controlled By:  Deployment/test-httpd
Replicas:       5 current / 5 desired
Pods Status:    5 Running / 0 Waiting / 0 Succeeded / 0 Failed
Pod Template:
  Labels:  app=test-httpd
           pod-template-hash=6dd4c6fb76
  Containers:
   httpd:
    Image:        httpd
    Port:         80/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Events:
  Type    Reason            Age   From                   Message
  ----    ------            ----  ----                   -------
  Normal  SuccessfulCreate  68s   replicaset-controller  Created pod: test-httpd-6dd4c6fb76-fxdt5
  Normal  SuccessfulCreate  68s   replicaset-controller  Created pod: test-httpd-6dd4c6fb76-8nsmh
  Normal  SuccessfulCreate  68s   replicaset-controller  Created pod: test-httpd-6dd4c6fb76-bhjl9
  Normal  SuccessfulCreate  68s   replicaset-controller  Created pod: test-httpd-6dd4c6fb76-2fl86
  Normal  SuccessfulCreate  68s   replicaset-controller  Created pod: test-httpd-6dd4c6fb76-mt8qn
查看任意一个Pod的详细信息，能够看到此Pod的完整的工作流程
# kubectl describe pod test-httpd-6dd4c6fb76-fxdt5
Name:         test-httpd-6dd4c6fb76-fxdt5
Namespace:    default
Priority:     0
Node:         node01/172.17.0.89
Start Time:   Wed, 19 May 2021 09:09:34 +0000
Labels:       app=test-httpd
              pod-template-hash=6dd4c6fb76
Annotations:  <none>
Status:       Running
IP:           10.244.1.3
IPs:
  IP:           10.244.1.3
Controlled By:  ReplicaSet/test-httpd-6dd4c6fb76
Containers:
  httpd:
    Container ID:   docker://03d6f36550596b83eaeb66f024f45a2faeab11e8acbf55a0c5c30d57113d7e4e
    Image:          httpd
    Image ID:       docker-pullable://httpd@sha256:e4c2b93c04762468a6cce6d507d94def02ef4dc285278d0d926e09827f4857db
    Port:           80/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Wed, 19 May 2021 09:09:49 +0000
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-dh94p (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-dh94p:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-dh94p
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason     Age    From               Message
  ----    ------     ----   ----               -------
  Normal  Scheduled  3m14s  default-scheduler  Successfully assigned default/test-httpd-6dd4c6fb76-fxdt5 to node01
  Normal  Pulling    3m12s  kubelet, node01    Pulling image "httpd"
  Normal  Pulled     3m1s   kubelet, node01    Successfully pulled image "httpd"
  Normal  Created    3m     kubelet, node01    Created container httpd
  Normal  Started    2m59s  kubelet, node01    Started container httpd
image.png

创建一个Service资源，要求与上述test-httpd进行关联

认情况下Service的资源类型Cluster IP， YAML文件中，spec.ports.port:描述的是Cluster IP的端口。
只是为后端的Pod提供了一个统一的访问入口（在k8s集群内有效）

vim test-httpd-svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: test-httpd-svc
spec:
  selector:
    app: test-httpd
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80

kubectl apply -f test-httpd-svc.yaml

kubectl get svc

kubectl get svc
NAME             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
kubernetes       ClusterIP   10.96.0.1       <none>        443/TCP   13m
test-httpd-svc   ClusterIP   10.109.147.35   <none>        80/TCP    6s

# curl 10.109.147.35
<html><body><h1>It works!</h1></body></html>

如果想要让外网能够访问到后端Pod，这里应该将Service的资源类型改为NodePort。

访问Cluster IP ,后端的Pod会轮替着为我们提供服务，也就是有负载均衡，如果没有Service资源，KUBE-PROXY组件也不会生效，因为它就是负责负载均衡，那么现在有了Service资源，它到底是怎么做到负载均衡的？底层的原理是什么？表面上来看，通过describe命令，查看SVC资源对应的Endpoint，就能够知道后端真正的Pod。

# vim  test-httpd-svc-nodeport.yaml
apiVersino: v1
kind: Service
metadata:
  name: test-httpd-svc
spec:
  selector:
    app: test-httpd
  type: NodePort
  ports:
      - protocol: TCP
        port: 80
       targetPort: 80
       nodePort:  30080 # NodePort的端口范围： 30000 - 32767

# kubectl delete svc test-httpd-svc
# kubectl apply -f  test-httpd-svc-nodeport.yaml
# kubectl get svc
NAME                      TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes                ClusterIP   10.96.0.1        <none>        443/TCP        23m
test-httpd-svc-nodeport   NodePort    10.105.227.168   <none>        80:30080/TCP   12s

# kubectl describe svc test-httpd-svc-nodeport
Name:                     test-httpd-svc-nodeport
Namespace:                default
Labels:                   <none>
Annotations:              Selector:  app=test-httpd
Type:                     NodePort
IP:                       10.105.227.168
Port:                     <unset>  80/TCP
TargetPort:               80/TCP
NodePort:                 <unset>  30080/TCP
Endpoints:                10.244.1.3:80,10.244.1.4:80,10.244.1.5:80 + 2 more...
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

# iptables-save |grep 10.105.227.168
-A KUBE-SERVICES ! -s 10.244.0.0/16 -d 10.105.227.168/32 -p tcp -m comment --comment "default/test-httpd-svc-nodeport: cluster IP" -m tcp --dport 80 -j KUBE-MARK-MASQ
-A KUBE-SERVICES -d 10.105.227.168/32 -p tcp -m comment --comment "default/test-httpd-svc-nodeport: cluster IP" -m tcp --dport 80 -j KUBE-SVC-5EC3ZPWMVIKQHGMU
# #如果目标地址是10.105.227.168/32的80端口，并且走的是TCP协议，那么就把这个流量跳转到KUBE-SVC-5EC3ZPWMVIKQHGMU

# iptables-save|grep 30080
-A KUBE-NODEPORTS -p tcp -m comment --comment "default/test-httpd-svc-nodeport:" -m tcp --dport 30080 -j KUBE-MARK-MASQ
-A KUBE-NODEPORTS -p tcp -m comment --comment "default/test-httpd-svc-nodeport:" -m tcp --dport 30080 -j KUBE-SVC-5EC3ZPWMVIKQHGMU

# iptables-save|grep KUBE-SVC-5EC3ZPWMVIKQHGMU
:KUBE-SVC-5EC3ZPWMVIKQHGMU - [0:0]
-A KUBE-NODEPORTS -p tcp -m comment --comment "default/test-httpd-svc-nodeport:" -m tcp --dport 30080 -j KUBE-SVC-5EC3ZPWMVIKQHGMU
-A KUBE-SERVICES -d 10.105.227.168/32 -p tcp -m comment --comment "default/test-httpd-svc-nodeport: cluster IP" -m tcp --dport 80 -j KUBE-SVC-5EC3ZPWMVIKQHGMU
-A KUBE-SVC-5EC3ZPWMVIKQHGMU -m comment --comment "default/test-httpd-svc-nodeport:" -m statistic --mode random --probability 0.20000000019 -j KUBE-SEP-WEJ2KHPB3UGJ3Q2L
-A KUBE-SVC-5EC3ZPWMVIKQHGMU -m comment --comment "default/test-httpd-svc-nodeport:" -m statistic --mode random --probability 0.25000000000 -j KUBE-SEP-KODG77QHMSNA4GDG
-A KUBE-SVC-5EC3ZPWMVIKQHGMU -m comment --comment "default/test-httpd-svc-nodeport:" -m statistic --mode random --probability 0.33333333349 -j KUBE-SEP-EWCOVBI4USNML6BQ
-A KUBE-SVC-5EC3ZPWMVIKQHGMU -m comment --comment "default/test-httpd-svc-nodeport:" -m statistic --mode random --probability 0.50000000000 -j KUBE-SEP-5Y2WLLQR22GOUUGX
-A KUBE-SVC-5EC3ZPWMVIKQHGMU -m comment --comment "default/test-httpd-svc-nodeport:" -j KUBE-SEP-VVJ4XJC3AZ6CMMFS

# iptables-save |grep KUBE-SEP-VVJ4XJC3AZ6CMMFS
:KUBE-SEP-VVJ4XJC3AZ6CMMFS - [0:0]
-A KUBE-SEP-VVJ4XJC3AZ6CMMFS -s 10.244.1.7/32 -m comment --comment "default/test-httpd-svc-nodeport:" -j KUBE-MARK-MASQ
-A KUBE-SEP-VVJ4XJC3AZ6CMMFS -p tcp -m comment --comment "default/test-httpd-svc-nodeport:" -m tcp -j DNAT --to-destination 10.244.1.7:80
-A KUBE-SVC-5EC3ZPWMVIKQHGMU -m comment --comment "default/test-httpd-svc-nodeport:" -j KUBE-SEP-VVJ4XJC3AZ6CMMFS

参数说明
SNAT： Source NAT 源地址转换
DNAT：Destination NAT 目标地址转换
MASQ：动态的源地址转换
Service：实现的负载均衡:默认使用的是iptables规则;

kubectl get pods -o wide
NAME                          READY   STATUS    RESTARTS   AGE   IP           NODE     NOMINATED NODE   READINESS GATES
test-httpd-6dd4c6fb76-2fl86   1/1     Running   0          35m   10.244.1.6   node01   <none>           <none>
test-httpd-6dd4c6fb76-8nsmh   1/1     Running   0          35m   10.244.1.4   node01   <none>           <none>
test-httpd-6dd4c6fb76-bhjl9   1/1     Running   0          35m   10.244.1.5   node01   <none>           <none>
test-httpd-6dd4c6fb76-fxdt5   1/1     Running   0          35m   10.244.1.3   node01   <none>           <none>
test-httpd-6dd4c6fb76-mt8qn   1/1     Running   0          35m   10.244.1.7   node01   <none>           <none>
# curl 10.244.1.6
<html><body><h1>It works!</h1></body></html>
# curl 10.244.1.3
<html><body><h1>It works!</h1></body></html>
# curl 10.244.1.5
<html><body><h1>It works!</h1></body></html>

# kubectl get svc
NAME                      TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes                ClusterIP   10.96.0.1        <none>        443/TCP        37m
test-httpd-svc-nodeport   NodePort    10.105.227.168   <none>        80:30080/TCP   14m

# curl 10.105.227.168
<html><body><h1>It works!</h1></body></html>

# nslookup test-httpd-svc-nodeport
Server:         127.0.0.53
Address:        127.0.0.53#53
# curl 127.0.0.53:30080
<html><body><h1>It works!</h1></body></html>
# kubectl get node -o wide
NAME           STATUS   ROLES    AGE     VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION       CONTAINER-RUNTIME
controlplane   Ready    master   5m43s   v1.18.0   172.17.0.19   <none>        Ubuntu 18.04.5 LTS   4.15.0-122-generic   docker://19.3.13
node01         Ready    <none>   5m13s   v1.18.0   172.17.0.21   <none>        Ubuntu 18.04.5 LTS   4.15.0-122-generic   docker://19.3.13

# curl 172.17.0.21:30080
<html><body><h1>It works!</h1></body></html>

相关文章

网友评论

      本文标题：创建deployment、service案例

      本文链接：https://www.haomeiwen.com/subject/mbipjltx.html

      延伸阅读

      深度阅读

      • 您也可以注册成为美文阅读网的作者，发表您的原创作品、分享您的心情！

      栏目导航

      热点阅读

      关于我们|服务条款|联系我们|创建deployment、service案例|投稿指南|网站地图|RSS订阅|排版工具|手机版

      提供经典美文摘抄,优美散文欣赏,现代诗歌精选,短篇小说,心情随笔,表白情书范文,故事会在线阅读欣赏

      Copyright © 2014-2023 Haomeiwen.com All Rights Reserved. 好美文阅读网 版权所有

      备案信息：桂公网安备 45052102000051号 · 桂ICP备13007215号-3

      本站所收录作品、热点评论等信息部分来源互联网，目的只是为了系统归纳学习和传递资讯

      所有作品版权归原创作者所有，与本站立场无关，如不慎侵犯了你的权益，请联系我们告知，我们将做删除处理！