K8s的api gateway---ambassador实操

对于api gateway，以前总是认知感觉和proxy差不多。

最近几天，撸完了ambassador的官方文档，才比较系统的了解了gateway的功能。

它和传统的nginx proxy或是k8s里的ingress还是有一定差别的。

近期准备在公司用起来。

一，Ambassador 是什么？

ambassador是datawire开源的服务网关，很好的支持kubernetes。具体详细介绍参考官网：https://www.getambassador.io/about/why-ambassador

Ambassador is an open source, Kubernetes-native API Gateway built on Envoy Proxy.

二，为什么先把Ambassador ？

网上关于K8S Ingress的比较文档：

http://tuohuang.info/ambassador-jwt-istio#.XVP-KfluaM8

https://juejin.im/post/5d4919ce5188251dff55b08f

https://www.lijiaocn.com/%E9%A1%B9%E7%9B%AE/2019/05/21/apigateway-base-envoy-compare.html

https://zhuanlan.zhihu.com/p/61364466

https://blog.csdn.net/hxpjava1/article/details/79375452

https://juejin.im/post/5bacb35b5188255c9e02dc71

http://www.sohu.com/a/314009713_465944

http://tuohuang.info/ambassador-jwt-istio#.XVtCjPkzbRY

https://www.getambassador.io

三，安装过程

1， 预先下载好镜像，应用如下yaml文件

https://getambassador.io/yaml/ambassador/ambassador-rbac.yaml

2， 针对实际情况，启动nodePort作为service。

---
apiVersion: v1
kind: Service
metadata:
  name: ambassador
spec:
  type: NodePort
  ports:
   - port: 80
     targetPort: 8080
  selector:
    service: ambassador

3， 测试nginx跳转

nginx.yaml内容如下(使用annotations 来进行声明式配置，方便分散管理。如果是default的命名空间，mapping中对应服务可省略.namespace后缀)：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deploy
spec:
  replicas: 1
  selector:
    matchLabels:
      name: nginx
  template:
    metadata:
      labels:
        name: nginx
    spec:
      containers:
        - name: nginx
          image: harbor.xxx.com.cn/base/middleware/nginx:1.13-alpine
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-service
  annotations:
    getambassador.io/config: |
      ---
      apiVersion: ambassador/v1
      kind: Mapping
      name: ngnix_mapping
      prefix: /
      service: nginx-service:80
      ---
      apiVersion: ambassador/v1
      kind: Mapping
      name: nginx-backend_mapping
      prefix: /backend/
      service: nginx-service:80
      labels:
        ambassador:
          - request_label:
            - nginx

spec:
  ports:
    - name: nginx
      port: 80
      targetPort: 80
      protocol: TCP
  selector:
    name: nginx

4， 测试tomcat跳转(request_label其实是在service多个port中来作过滤选择的)

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat-deploy
spec:
  replicas: 2
  selector:
    matchLabels:
      app: tomcat-deploy
  template:
    metadata:
      labels:
        app: tomcat-deploy
    spec:
      containers:
      - name: tomcat
        image: harbor.xxx.com.cn/official_hub/tomcat:8.5.23.0
        imagePullPolicy: IfNotPresent
        ports:
            - containerPort: 8080

---
apiVersion: v1
kind: Service
metadata:
    name: tomcat-svc
    annotations:
      getambassador.io/config: |
        ---
        apiVersion: ambassador/v1
        kind: Mapping
        name: tomcat_mapping
        prefix: /tomcat-svc
        service: tomcat-svc.default:8080
        ---
        apiVersion: ambassador/v1
        kind: Mapping
        name: tomcat-backend_mapping
        prefix: /tomcat/
        service: tomcat-svc.default:8080
        labels:
          ambassador:
            - request_label:
              - tomcat
spec:
  ports:
    - name: tomcat
      port: 8080
      targetPort: 8080
  selector:
    app: tomcat-deploy

5， 验证

根据几节的内容，分别访问如下几个url，检测其生效。

http://3.2.10.1:xxxx/ambassador/v0/diag/
http://3.2.10.1:30080/backend/hello.html
http://3.2.10.1:30080/tomcat/

四，ambassador性能监控

1，  zipkin作api调用性能分析

参考url：https://www.getambassador.io/user-guide/tracing-tutorial

---
apiVersion: v1
kind: Service
metadata:
  name: zipkin
  annotations:
    getambassador.io/config: |
      ---
      apiVersion: ambassador/v1
      kind: TracingService
      name: tracing
      service: zipkin:9411
      driver: zipkin
spec:
  selector:
    app: zipkin
  ports:
  - port: 9411
    name: http
    targetPort: http
    nodePort: 32764
  type: NodePort
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: zipkin
spec:
  replicas: 1
  strategy:
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: zipkin
    spec:
      containers:
      - name: zipkin
        image: harbor.xxx.com.cn/3rd_part/openzipkin/zipkin:2.16
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 9411

http://3.3.10.5:xxx/zipkin

2，  Prometheus,grafana作api的性能展示

参考URL：https://www.getambassador.io/user-guide/monitoring

【这是基于prometheus operator安装的，可能要和现在整合】