Ambassador系列-03-服務配置和服務發現

Ambassador 服務配置

Ambassador提供了三種服務配置方法。

CRDs方式：Customer Resource Definitions
註解方式：Kubernetes Service Annotations
Ingress方式：Kubernetes Ingress

CRDs方式

Ambassador系列-01-介紹、安裝和使用一節中使用的就是CRDs方式，路由規則都定義在Mapping CRD中。

---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: echo-server-mapping
spec:
  prefix: /
  service: echo:8080

註解方式

在Service中增加Mapping註解，該Mapping只對該Service生效。prefix爲路徑前綴，service爲服務名+端口，後面有詳細解釋。

vi httpbin-service.yaml
---
apiVersion: v1
kind: Service
metadata:
  name: httpbin
  annotations:
    getambassador.io/config: |
      ---
      apiVersion: ambassador/v1
      kind: Mapping
      name: httpbin-mapping
      prefix: /http
      service: httpbin:80
  labels:
    app: httpbin
spec:
  ports:
  - name: http
    port: 80
    targetPort: 80
  selector:
    app: httpbin
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: httpbin
spec:
  replicas: 1
  selector:
    matchLabels:
      app: httpbin
  template:
    metadata:
      labels:
        app: httpbin
    spec:
      containers:
      - image: docker.io/kennethreitz/httpbin
        name: httpbin
        ports:
        - containerPort: 80

kubectl apply -f httpbin-service.yaml
service/httpbin created
deployment.apps/httpbin created

kubectl get pod
NAME                         READY   STATUS    RESTARTS   AGE
ambassador-877b57b69-cvzbl   1/1     Running   1          8d
ambassador-877b57b69-rtgcq   1/1     Running   1          8d
echo-5599595fd9-2vfnt        1/1     Running   1          8d
echo-5599595fd9-ffxpn        1/1     Running   1          8d
httpbin-8c4b74ffb-f5j6b      1/1     Running   0          7m54s

驗證一下。

curl -i http://192.168.1.50:38080/http/status/200
HTTP/1.1 200 OK
server: envoy
date: Sat, 07 Dec 2019 03:35:56 GMT
content-type: text/html; charset=utf-8
access-control-allow-origin: *
access-control-allow-credentials: true
content-length: 0
x-envoy-upstream-service-time: 6
lua-scripts-enabled: Processed

Ingress方式

Ambassador支持Ingress Controller，在Ingress中的配置下發給Ambassador，最終應用到Envoy中。

vi echo-server-ingress.yaml
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: ambassador
  name: echo-server-ingress
spec:
  rules:
  - http:
      paths:
      - path: /bar/
        backend:
          serviceName: echo
          servicePort: 8080

kubectl apply -f echo-server-ingress.yaml

curl -i http://192.168.1.50:38080/bar
HTTP/1.1 200 OK
date: Sat, 07 Dec 2019 03:57:59 GMT
content-type: text/plain
server: envoy
x-envoy-upstream-service-time: 2
lua-scripts-enabled: Processed
transfer-encoding: chunked


Hostname: echo-5599595fd9-2vfnt

Pod Information:
        node name:      k8s-node1
        pod name:       echo-5599595fd9-2vfnt
        pod namespace:  default
        pod IP: 10.244.1.4

Server values:
        server_version=nginx: 1.14.2 - lua: 10015

Request Information:
        client_address=10.244.1.5
        method=GET
        real path=/
        query=
        request_version=1.1
        request_scheme=http
        request_uri=http://192.168.1.50:8080/

Request Headers:
        accept=*/*
        content-length=0
        host=192.168.1.50:38080
        user-agent=curl/7.29.0
        x-envoy-expected-rq-timeout-ms=3000
        x-envoy-internal=true
        x-envoy-original-path=/bar
        x-forwarded-for=10.244.0.0
        x-forwarded-proto=http
        x-request-id=b7463d93-bf82-483c-8717-ad55c4d2088d

Request Body:
        -no body in request-