我在使用流量入口控制器的k8集群上部署了3个服务。访问我的Angular内置前端时出现502 Bad Gateway错误，但是通过后端节点服务器和mongo db可以正常工作。
我已经尝试过设置具有相同问题的Nginx入口控制器。我知道该应用程序的生产版本对于最终版本会更好，但据我所知，仍然可以进行开发人员访问。 Traefik入口根据IP和端口正确路由，但在此过程中某处失败。我已经执行了'frontend'窗格，curl确认页面已按预期托管在localhost：4200上。
我的docker-compose文件如下：
version: '3.7'
services:
frontend:
image: [image location]
ports:
- "4200"
volumes:
- ./frontend:/app
s3-server:
image: [image location]
ports:
- "3000"
links:
- database
database:
image: mongo
ports:
- "27017"
我的traefik yaml如下：
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: frontend
annotations:
kubernetes.io/ingress.class: traefik
spec:
rules:
- host: [domainname]
http:
paths:
- path: /
backend:
serviceName: frontend
servicePort: 4200
- path: /api
backend:
serviceName: s3-server
servicePort: 3000
- path: /db
backend:
serviceName: database
servicePort: 27017
前端服务（由compose创建）yaml：
apiVersion: v1
kind: Service
metadata:
annotations:
kompose.cmd: kompose convert
kompose.version: 1.21.0 ()
creationTimestamp: null
labels:
io.kompose.service: frontend
name: frontend
spec:
ports:
- name: "4200"
port: 4200
targetPort: 4200
selector:
io.kompose.service: frontend
status:
loadBalancer: {}
入口显示：
Host Path Backends
---- ---- --------
api.cailean.tech
/ frontend:4200 (192.168.1.27:4200)
/api s3-server:3000 (192.168.2.20:3000)
/db database:27017 (192.168.2.14:27017)
豆荚秀：
pod/database-798b8df4bd-zzxpx 1/1 Running 0 17h 192.168.2.14 kube-node-ea4d <none> <none>
pod/s3-server-76dd6b6b57-pq9lp 1/1 Running 0 15h 192.168.2.20 kube-node-ea4d <none> <none>
pod/nginx-86c57db685-qbcd4 1/1 Running 0 47m 192.168.1.26 kube-node-f94c <none> <none>
pod/frontend-5b8c7979d8-fggr6 1/1 Running 0 18m 192.168.1.27 kube-node-f94c <none> <none>
k描述svc前端：
Name: frontend
Namespace: default
Labels: io.kompose.service=frontend
Annotations: kompose.cmd: kompose convert
kompose.version: 1.21.0 ()
kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"v1","kind":"Service","metadata":{"annotations":{"kompose.cmd":"kompose convert","kompose.version":"1.21.0 ()"},"creationTim...
Selector: io.kompose.service=frontend
Type: ClusterIP
IP: 192.168.141.36
Port: 4200 4200/TCP
TargetPort: 4200/TCP
Endpoints: 192.168.1.27:4200
Session Affinity: None
Events: <none>
当连接到Nginx服务器pod（用于测试）时，如果我卷曲前端的IP地址，我会被拒绝连接。
* Expire in 0 ms for 6 (transfer 0x559ae5cb5f50)
* Trying 192.168.1.27...
* TCP_NODELAY set
* Expire in 200 ms for 4 (transfer 0x559ae5cb5f50)
* connect to 192.168.1.27 port 4200 failed: Connection refused
* Failed to connect to 192.168.1.27 port 4200: Connection refused
* Closing connection 0
curl: (7) Failed to connect to 192.168.1.27 port 4200: Connection refused
前端吊舱内的卷曲给我：
Rebuilt URL to: localhost:4200/
* Trying ::1...
* TCP_NODELAY set
* connect to ::1 port 4200 failed: Connection refused
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 4200 (#0)
> GET / HTTP/1.1
> Host: localhost:4200
> User-Agent: curl/7.52.1
> accept: */*
>
< HTTP/1.1 200 OK
< X-Powered-By: Express
< access-control-allow-origin: *
< accept-Ranges: bytes
< Content-Type: text/html; charset=UTF-8
< Content-Length: 761
< etag: W/"2f9-Ft4snhWFNqmPXU8vVB/M50CiWRU"
< Date: Tue,14 Apr 2020 12:54:50 GMT
< Connection: keep-alive
<
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>S3 Manoeuvre Selector</title>
<base href="/">
<meta name="viewport" content="width=device-width,initial-scale=1">
<link rel="icon" type="image/x-icon" href="favicon.ico">
<link href="https://fonts.googleapis.com/css?family=Roboto:300,400,500&display=swap" rel="stylesheet">
<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
</head>
<body class="mat-typography">
<app-root></app-root>
<script src="runtime.js" type="module"></script><script src="polyfills.js" type="module"></script><script src="styles.js" type="module"></script><script src="vendor.js" type="module"></script><script src="main.js" type="module"></script></body>
</html>
* Curl_http_done: called premature == 0
* Connection #0 to host localhost left intact
如您所见，它最初会失败，但可以正确解决。有什么解决办法吗？
有什么主意，为什么Bad Gateway用于有角度的前端而不是mongo db或express api？
更新： 对服务yaml进行4-6次任意更改并使用'kubectl apply -f'将不会导致严重的网关错误并按预期工作，即使该服务yaml与最初用于启动该服务的yaml完全相同。无法找到任何可能的原因……