My goal is to monitor services with Prometheus, so I was following a guide located at:

https://github.com/coreos/prometheus-operator/blob/master/Documentation/user-guides/getting-started.md

I am relatively new to all of this, so please forgive my naiveness. I tried looking into the error, but all the answers were convoluted. I have no idea where to start on the debug process (perhaps look into the YAMLs?)

I wanted to monitor a custom Service. So, I deployed a service.yaml of the following into a custom namespace (t):

kind: Service
apiVersion: v1
metadata:
  namespace: t
  name: example-service-test
  labels:
    app: example-service-test
spec:
  selector:
    app: example-service-test
  type: NodePort
  ports:
  - name: http
    nodePort: 30901
    port: 8080
    protocol: TCP
    targetPort: http
---
apiVersion: v1
kind: Pod
metadata:
  name: example-service-test
  namespace: t
  labels:
    app: example-service-test
spec:
  containers:
  - name: example-service-test
    image: python:2.7
    imagePullPolicy: IfNotPresent
    command: ["/bin/bash"]
    args: ["-c", "echo \"<p>This is POD1 $(hostname)</p>\" > index.html; python -m SimpleHTTPServer 8080"]
    ports:
    - name: http
      containerPort: 8080

And deployed a service monitor into the namespace:

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: example-service-test
  labels:
    team: frontendtest1
  namespace: t
spec:
  selector:
    matchLabels:
      app: example-service-test
  endpoints:
  - port: http

So far, the service monitor is detecting the service, as shown: Prometheus Service Discovery. However, there is an error with obtaining the metrics from the service: Prometheus Targets.

From what I know, prometheus isn't able to access the /metrics on the sample service - in that case, do I need to expose the metrics? If so, could I get a step by step guide solution to how to expose metrics? If not, what route should I take?