Kubernetes 可以连接两个集群 IP 服务吗？

Question

情况是我想连接一个租户内的两个集群 IP 服务，该租户已经将 Traefik 作为 NodePort，以便这两个服务中的任何一个都可以是 LoadBalancer，因为 NodePort 被 Traefik 使用。

我尝试连接的两个服务的工作方式如下。第一个，我称之为 "Master"，将从客户端收到带有文本的 post，并将调用另一个名为 "slave" 的服务，后者将添加一些文本（"Hola Patri") 到客户端发送的文本。这两个服务是Docker镜像中app.py定义的flask服务。您可以在下面的两张图片中看到 app.py：

master/app.py

from flask import Flask, request
import requests                                                                                                                                                                                                                                                                                                                                                       

app = Flask(__name__)                                                              

@app.route("/", methods = ['GET', 'POST'])                                                 

def put(): 
    if request.method == 'POST':                                                    
        text = request.get_data()  
        r = requests.post("http://slave:5001",data=text)   
        result = r.text
        return result                                                        

if __name__ == '__main__':                                                         
    app.run(host="0.0.0.0", port=5000, debug=True)

slave/app.py

from flask import Flask, request                                                                                                                                                                                                                                                                                                                                                       

app = Flask(__name__)                                                              

@app.route("/", methods = ['GET', 'POST'])                                                 

def put(): 
    if request.method == 'POST':                                                    
        text = request.get_data()
        #text = request.data
        texto_final = str(text) + 'Hola Patri'                                                      
        return texto_final                                                     

if __name__ == '__main__':                                                         
    app.run(host="0.0.0.0", port=5001, debug=True)

部署和服务的配置在两个 yaml 中定义：master_src.yaml 和 slave_src.yaml。

master_src.yaml

kind: Namespace
apiVersion: v1
metadata:
  name: innovation
  labels:
    name: innovation

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: master
  namespace: innovation
spec:
  replicas: 1
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      securityContext:
        runAsUser: 1000
        fsGroup: 1000            
      containers:
      - name: master
        imagePullPolicy: Always
        securityContext:
            runAsUser: 1000
            runAsNonRoot: true
        image: reg-dhc.app.corpintra.net/galiani/innovation:mastertest
        ports:
        - protocol: TCP
          containerPort: 5000
      imagePullSecrets:
        - name: galiani-innovation-pull-secret

---
apiVersion: v1
kind: Service
metadata:
  name: master
  namespace: innovation
spec:
  ports:
  - protocol: TCP
    port: 5000
    targetPort: 5000
  selector:
    app: myapp

slave_src.yaml

kind: Namespace
apiVersion: v1
metadata:
  name: innovation
  labels:
    name: innovation

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: slave
  namespace: innovation
spec:
  replicas: 1
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      securityContext:
        runAsUser: 1000
        fsGroup: 1000  
      containers:
      - name: slave
        imagePullPolicy: Always
        securityContext:
            runAsUser: 1000
            runAsNonRoot: true
        image: reg-dhc.app.corpintra.net/galiani/innovation:slavetest
        ports:
        - protocol: TCP
          containerPort: 5001
      imagePullSecrets:
        - name: galiani-innovation-pull-secret

---
apiVersion: v1
kind: Service
metadata:
  name: slave
  namespace: innovation
spec:
  selector:
    app: myapp
  ports:
  - protocol: TCP
    port: 5001
    targetPort: 5001

我还创建了一个网络策略来允许两个服务之间的流量。用于定义网络策略的 yaml 如下。

networkpolicy_src.yaml

kind: NetworkPolicy
apiVersion: extensions/v1beta1
metadata:
  name: ingress-to-all
  namespace: innovation
spec:
  podSelector:
    matchLabels:
      app: myapp
  ingress: 
  - from:
    - podSelector:
        matchLabels:
          app: myapp
    ports:
      - port: 5000
        protocol: TCP
      - port: 5001
        protocol: TCP
  policyTypes:
  - Ingress

主服务和从服务之间的连接不工作。我可以独立访问主从。然而，当我尝试向主服务器（使用 curl）创建 POST 并且它应该连接到从服务器时，我收到以下错误：

curl: (52) Empty reply from server

提前感谢您的帮助！

关于使用 traefik 连接的新问题。这是 trafik ingress 的 yaml：

kind: Ingress
apiVersion: extensions/v1beta1
metadata:
  name: ingress-innovation
  namespace: innovation
  annotations:
    traefik.frontend.rule.type: PathPrefixStrip
spec:  
  rules:
  - http:
      paths:
      - path: /master
        backend:
          serviceName: master
          servicePort: 5000
      - path: /slave
        backend:
          serviceName: slave
          servicePort: 5001

我也更正了 networkpolicy yaml，现在是：

kind: NetworkPolicy
apiVersion: extensions/v1beta1
metadata:
  name: master-to-slave
  namespace: innovation
spec:
  podSelector:
    matchLabels:
      app: app-slave
  ingress:
    - ports:
      - port: 5000
        protocol: TCP
      - port: 5001
        protocol: TCP
    - from:
      - namespaceSelector:
          matchLabels:
            app: app-master

再次感谢您的帮助！

Answer 1

问题可能是主控和从属具有相同的标签 app: myapp。将主部署和服务的标签更改为 app: master，从属部署和服务的标签更改为 app: slave。

Kubernetes 可以连接两个集群 IP 服务吗？

Could two cluster IP services be connected in Kubernetes?

kubernetes

traefik

kubernetes-service

kubernetes-networkpolicy