502 bad gateway using Kubernetes with Ingress controller - kubernetes

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.