为什么这种在 kubernetes (GKE) 上轮廓的设置会导致 2 个正常运行的外部 IP?

Question

我一直在测试GKE kubernetes集群上尝试将contour作为替代入口控制器。

在经过一些修改的轮廓部署文档之后，我有一个提供测试 HTTP 响应的工作设置。

首先，我创建了一个"helloworld"pod，它提供http响应，通过NodePort服务和入口公开：

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: helloworld
spec:
replicas: 4
template:
metadata:
labels:
app: helloworld
spec:
containers:
- name: "helloworld-http"
image: "nginxdemos/hello:plain-text"
imagePullPolicy: Always
resources:
requests:
cpu: 250m
memory: 256Mi
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
podAffinityTerm:
labelSelector:
matchExpressions:
- key: app
operator: In
values:
- helloworld
topologyKey: "kubernetes.io/hostname"
---
apiVersion: v1
kind: Service
metadata:
name: helloworld-svc
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: helloworld
sessionAffinity: None
type: NodePort
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: helloworld-ingress
spec:
backend:
serviceName: helloworld-svc
servicePort: 80

然后，我为直接从他们的文档中复制contour创建了一个部署：

apiVersion: v1
kind: Namespace
metadata:
name: heptio-contour
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: contour
namespace: heptio-contour
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
app: contour
name: contour
namespace: heptio-contour
spec:
selector:
matchLabels:
app: contour
replicas: 2
template:
metadata:
labels:
app: contour
annotations:
prometheus.io/scrape: "true"
prometheus.io/port: "9001"
prometheus.io/path: "/stats"
prometheus.io/format: "prometheus"
spec:
containers:
- image: docker.io/envoyproxy/envoy-alpine:v1.6.0
name: envoy
ports:
- containerPort: 8080
name: http
- containerPort: 8443
name: https
command: ["envoy"]
args: ["-c", "/config/contour.yaml", "--service-cluster", "cluster0", "--service-node", "node0", "-l", "info", "--v2-config-only"]
volumeMounts:
- name: contour-config
mountPath: /config
- image: gcr.io/heptio-images/contour:master
imagePullPolicy: Always
name: contour
command: ["contour"]
args: ["serve", "--incluster"]
initContainers:
- image: gcr.io/heptio-images/contour:master
imagePullPolicy: Always
name: envoy-initconfig
command: ["contour"]
args: ["bootstrap", "/config/contour.yaml"]
volumeMounts:
- name: contour-config
mountPath: /config
volumes:
- name: contour-config
emptyDir: {}
dnsPolicy: ClusterFirst
serviceAccountName: contour
terminationGracePeriodSeconds: 30
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
podAffinityTerm:
labelSelector:
matchLabels:
app: contour
topologyKey: kubernetes.io/hostname
---
apiVersion: v1
kind: Service
metadata:
name: contour
namespace: heptio-contour
spec:
ports:
- port: 80
name: http
protocol: TCP
targetPort: 8080
- port: 443
name: https
protocol: TCP
targetPort: 8443
selector:
app: contour
type: LoadBalancer
---

默认和七轮廓命名空间现在如下所示：

$ kubectl get pods,svc,ingress -n default
NAME                              READY     STATUS    RESTARTS   AGE
pod/helloworld-7ddc8c6655-6vgdw   1/1       Running   0          6h
pod/helloworld-7ddc8c6655-92j7x   1/1       Running   0          6h
pod/helloworld-7ddc8c6655-mlvmc   1/1       Running   0          6h
pod/helloworld-7ddc8c6655-w5g7f   1/1       Running   0          6h
NAME                     TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
service/helloworld-svc   NodePort    10.59.240.105   <none>        80:31481/TCP   34m
service/kubernetes       ClusterIP   10.59.240.1     <none>        443/TCP        7h
NAME                                    HOSTS     ADDRESS         PORTS     AGE
ingress.extensions/helloworld-ingress   *         y.y.y.y   80        34m
$ kubectl get pods,svc,ingress -n heptio-contour
NAME                          READY     STATUS    RESTARTS   AGE
pod/contour-9d758b697-kwk85   2/2       Running   0          34m
pod/contour-9d758b697-mbh47   2/2       Running   0          34m
NAME              TYPE           CLUSTER-IP     EXTERNAL-IP     PORT(S)                      AGE
service/contour   LoadBalancer   10.59.250.54   x.x.x.x   80:30882/TCP,443:32746/TCP   34m

有 2 个可公开路由的 IP 地址：

• x.x.x.x - 转发到轮廓 Pod 的 GCE TCP 负载均衡器
• y.y.y.y - 一个GCE HTTP负载均衡器，通过helloworld入口转发到helloworld pods

两个公共 IP 上的curl都会从 helloworld pod 返回有效的 HTTP 响应。

# the TCP load balancer
$ curl -v x.x.x.x
* Rebuilt URL to: x.x.x.x/  
*   Trying x.x.x.x...
* TCP_NODELAY set
* Connected to x.x.x.x (x.x.x.x) port 80 (#0)
> GET / HTTP/1.1
> Host: x.x.x.x
> User-Agent: curl/7.58.0
> Accept: */*
>
< HTTP/1.1 200 OK
< server: envoy
< date: Mon, 07 May 2018 14:14:39 GMT
< content-type: text/plain
< content-length: 155
< expires: Mon, 07 May 2018 14:14:38 GMT
< cache-control: no-cache
< x-envoy-upstream-service-time: 1
<
Server address: 10.56.4.6:80
Server name: helloworld-7ddc8c6655-w5g7f
Date: 07/May/2018:14:14:39 +0000
URI: /
Request ID: ec3aa70e4155c396e7051dc972081c6a
# the HTTP load balancer
$ curl http://y.y.y.y 
* Rebuilt URL to: y.y.y.y/
*   Trying y.y.y.y...
* TCP_NODELAY set
* Connected to y.y.y.y (y.y.y.y) port 80 (#0)
> GET / HTTP/1.1
> Host: y.y.y.y
> User-Agent: curl/7.58.0
> Accept: */*
> 
< HTTP/1.1 200 OK
< Server: nginx/1.13.8
< Date: Mon, 07 May 2018 14:14:24 GMT
< Content-Type: text/plain
< Content-Length: 155
< Expires: Mon, 07 May 2018 14:14:23 GMT
< Cache-Control: no-cache
< Via: 1.1 google
< 
Server address: 10.56.2.8:80
Server name: helloworld-7ddc8c6655-mlvmc
Date: 07/May/2018:14:14:24 +0000
URI: /
Request ID: 41b1151f083eaf30368cf340cfbb92fc

我有两个公共 IP 是设计使然吗？我应该为客户使用哪一个？我可以根据自己的偏好在 TCP 和 HTTP 负载均衡器之间进行选择吗？

Answer 1

可能您配置了 GLBC 入口 (https://github.com/kubernetes/ingress-gce/blob/master/docs/faq/gce.md#how-do-i-disable-the-gce-ingress-controller)

您可以尝试使用以下入口定义吗？

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
kubernetes.io/ingress.class: "contour"
name: helloworld-ingress
spec:
backend:
serviceName: helloworld-svc
servicePort: 80

如果您想确保您的流量通过轮廓，您应该使用x.x.x.xip。