使用带有 Ingress 控制器的 Kubernetes 的 502 错误网关

Question

I have a Kubernetes setup on Minikube with this configuration:

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myappdeployment
spec:
  replicas: 5
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: custom-docker-image:latest
          ports:
            - containerPort: 3000

---
kind: Service
apiVersion: v1
metadata:
  name: example-service
spec:
  selector:
    app: myapp
  ports:
    - protocol: "TCP"
      # Port accessible inside cluster
      port: 3000
      # Port to forward to inside the pod
      targetPort: 3000
  type: NodePort

---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
  - http:
      paths:
      - path: /
        backend:
          serviceName: example-service
          servicePort: 3000

I took a look at the solution to this Stackoverflow post and it seems my configuration is.. fine?

What am I doing wrong to get 502 Bad Gateway when accessing http://192.xxx.xx.x , my Minikube address? The nginx-ingress-controller logs say:

...
Connection refused while connecting to upstream
...

Another odd piece of info, when I follow this guide to setting up the basic node service on Kubernetes, everything works and I see a "Hello world" page when I open up the Minikube add

Answer 1

Steps taken: I ran

kubectl port-forward pods/myappdeployment-5dff57cfb4-6c6bd 3000:3000

Then I visited localhost:3000 and saw

This page isn’t working
localhost didn’t send any data.
ERR_EMPTY_RESPONSE

I figured the reason is more obvious in the logs so I ran

kubectl logs pods/myappdeployment-5dff57cfb4-6c6bd 

and got

Waiting for MySQL...
no destination
Waiting for MySQL...
no destination
Waiting for MySQL...
no destination
Waiting for MySQL...
no destination
...

Thus I reasoned that I was originally getting a 502 because all of the pods were not running due to no MySQL setup.