下载掌阅APP，畅读海量书库
立即打开
6.2 部署服务 |
|
本节主要介绍服务部署时使用的yaml文件，以及如何在Kubernetes集群中部署查看服务。
1.服务部署yaml文件说明
每个服务部署yaml文件的大同小异，这里仅以service-go示例说明：
1 kind: Service 2 apiVersion: v1 3 metadata: 4 name: service-go 5 labels: 6 app: service-go 7 spec: 8 selector: 9 app: service-go 10 ports: 11 - name: http 12 port: 80 13 --- 14 apiVersion: apps/v1 15 kind: Deployment 16 metadata: 17 name: service-go-v1 18 spec: 19 selector: 20 matchLabels: 21 app: service-go 22 version: v1 23 replicas: 1 24 template: 25 metadata: 26 labels: 27 app: service-go 28 version: v1 29 spec: 30 restartPolicy: Always 31 containers: 32 - name: service-go 33 image: registry.cn-shanghai.aliyuncs.com/istio-lab/service-go:v1 34 ports: 35 - containerPort: 80 36 resources: 37 requests: 38 cpu: 50m 39 memory: 50Mi 40 limits: 41 cpu: 100m 42 memory: 100Mi 43 --- 44 apiVersion: apps/v1 45 kind: Deployment 46 metadata: 47 name: service-go-v2 48 spec: 49 selector: 50 matchLabels: 51 app: service-go 52 version: v2 53 replicas: 1 54 template: 55 metadata: 56 labels: 57 app: service-go 58 version: v2 59 spec: 60 restartPolicy: Always 61 containers: 62 - name: service-go 63 image: registry.cn-shanghai.aliyuncs.com/istio-lab/service-go:v2 64 ports: 65 - containerPort: 80 66 resources: 67 requests: 68 cpu: 50m 69 memory: 50Mi 70 limits: 71 cpu: 100m 72 memory: 100Mi
第1～12行是Kubernetes中的Service定义，第4行指定了服务名为service-go，第8、9行指定选择包含标签app=service-go的Pod，第11、12行指定服务开放在80端口，由于没有指定targetPort，则targetPort默认与port参数一致，即后端Pod开放的端口也应该是80端口。
第14～42行是Kubernetes的Deployment定义，第17行定义了Deployment的名称为service-go-v1。第19到22行定义了Deployment管理的是包含app=service-go，且version=v1标签的Pod。第26到28行的定义表示为启动的Pod添加app=service-go和version=v1的标签。第30行定义了重启策略为Always，此策略表示不论何种情况下，只要Pod状态不正常就持续重启。第32～42行定义了Pod启动一个名称为service-go的容器。第33行定义了service-go容器使用的Docker镜像及版本，第35行定义了容器开放了80端口。第36～42行定义了容器运行时需要的资源情况，requests定义了容器启动时需要的CPU和内存资源，limits定义了容器最多能使用的CPU和内存资源。
第44～72行定义了service-go-v2的Deployment配置，与service-go-v1类似，在此不再赘述。
从上面的Service定义可以知道，Service选择了所有包含了标签名为app、值为service-go的Pod，而这包含service-go-v1和service-go-v2管理的Pod，因此请求流量会轮询地发送给服务的v1版本和v2版本。
如果你是一个Kubernetes的用户，你可能会发现，此次实验编写的Deployment中并没有使用Kubernetes的健康查检机制liveness和探测机制readiness。这是由于Envoy代理会对服务实例进行健康查检，而且如果你使用了Istio的自动TLS来加密服务间的通信时，由于Kubernetes进行健康检查时没用TLS，这可能会导致Kubernetes健康检查失败，进而导致Pod被反复重启，影响服务的稳定性。当然也可以通过其他方式来实现，绕过Istio的TLS来完成Kubernetes的健康检查，在后面的章节中，也会介绍此类方法。
其他服务的yaml部署文件类似，只是部署名称和app标签值有改动，如service-node、service-lua等值会改动。
2.在Kubernetes集群中部署服务
1）部署服务
使用上节介绍的服务部署yaml文件进行部署：
$ kubectl apply -f service/go/service-go.yaml service/service-go created deployment.apps/service-go-v1 created deployment.apps/service-go-v2 created $ kubectl apply -f service/node/service-node.yaml service/service-node created deployment.apps/service-node-v1 created deployment.apps/service-node-v2 created $ kubectl apply -f service/lua/service-lua.yaml service/service-lua created deployment.apps/service-lua-v1 created deployment.apps/service-lua-v2 created $ kubectl apply -f service/python/service-python.yaml service/service-python created deployment.apps/service-python-v1 created deployment.apps/service-python-v2 created $ kubectl apply -f service/js/service-js.yaml service/service-js created deployment.apps/service-js-v1 created deployment.apps/service-js-v2 created
2）查看服务部署状态：
$ kubectl get deploy NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE service-go-v1 1 1 1 1 3h28m service-go-v2 1 1 1 1 3h28m service-js-v1 1 1 1 1 3h28m service-js-v2 1 1 1 1 3h28m service-lua-v1 1 1 1 1 3h28m service-lua-v2 1 1 1 1 3h28m service-node-v1 1 1 1 1 3h28m service-node-v2 1 1 1 1 3h28m service-python-v1 1 1 1 1 3h28m service-python-v2 1 1 1 1 3h28m $ kubectl get pod NAME READY STATUS RESTARTS AGE service-go-v1-7cc5c6f574-2dn6n 1/1 Running 0 3h29m service-go-v2-7656dcc478-2dgc6 1/1 Running 0 3h29m service-js-v1-55756d577-49cl5 1/1 Running 0 3h29m service-js-v2-86bdfc86d9-pbq2d 1/1 Running 0 3h29m service-lua-v1-5c9bcb7778-hsbr6 1/1 Running 0 3h29m service-lua-v2-75cb5cdf8-75tm4 1/1 Running 0 3h29m service-node-v1-d44b9bf7b-6hrzd 1/1 Running 0 3h29m service-node-v2-86545d9796-4ttsf 1/1 Running 0 3h29m service-python-v1-79fc5849fd-vtzsf 1/1 Running 0 3h29m service-python-v2-7b6864b96b-9qk8c 1/1 Running 0 3h29m $ kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 4h47m service-go ClusterIP 10.108.207.28 <none> 80/TCP 3h29m service-js ClusterIP 10.97.251.7 <none> 80/TCP 3h29m service-lua ClusterIP 10.103.165.139 <none> 80/TCP 3h29m service-node ClusterIP 10.102.21.34 <none> 80/TCP 3h29m service-python ClusterIP 10.103.119.8 <none> 80/TCP 3h29m