Getting Connection refused while trying to access service from kubernetes pod-CodePudding

I am new to kubernetes and I am trying to learn it by deploying a simple node server using AWS EKS. (kubernetes is alreay setup to talk to the created AWS EKS cluster)

Here is code for my simple node file (server.js)

const express = require('express')
const app = express()
const port = 8080

app.get('/', (req, res) => {
 res.send('Hello World!')
})

app.listen(port, () => {
console.log(`Example app listening at http://localhost:${port}`)
})

Here is how the Dockerfile looks like:

FROM node:12
# Create app directory
WORKDIR /usr/src/app
# Install app dependencies
COPY package*.json ./
RUN npm ci
# Bundle app source
COPY . .
EXPOSE 8080
CMD [ "node", "server.js" ]

I am able to run the above server in my local by creating a docker image.

Now, in order to deploy this server here are the steps that I followed:
First, I pushed the above image to doceker hub (aroraankit7/simple-server) Second, I created a deployment.yaml file which looks like this:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: simple-server-app
  labels:
    app: simple-server-app
spec:
  replicas: 2
  selector:
    matchLabels:
      app: simple-server-app
   template:
     metadata:
       labels:
         app: simple-server-app
     spec:
       containers:
       - name: simple-server
         image: aroraankit7/simple-server:v1
         ports:
         - containerPort: 8080

Third, I deployed this using kubectl apply command. Here is the output for kubectl get pods

Then, I created the service.yaml file. Here is how it looks:

apiVersion: v1
kind: Service
metadata:
name: simple-server-svc
labels:
  run: simple-server
spec:
  ports:
  - port: 8080
    targetPort: 8080
    protocol: TCP
  selector:
    run: simple-server

I then deployed this using the kubectl apply command. Output for kubectl describe services:

Next, I logged into on of my pods by using the command: kubectl -it exec simple-server-app-758dfb88f4-4cfmp bash

While inside this pod, I ran the following the command: curl http://simple-server-svc:8080 and this was the output that I got: curl: (7) Failed to connect to simple-server-svc port 8080: Connection refused

Why is the connection getting refused?

When I am running curl http:localhost://8080, I am getting the right output (Hello World! in this case)

CodePudding user response：

Your service is not bound to the deployment. You need to modify the selector in your service.yaml to the following:

apiVersion: v1
kind: Service
metadata:
 name: simple-server-svc
 labels:
  run: simple-server
spec:
  ports:
  - port: 8080
    targetPort: 8080
    protocol: TCP
  selector:
    app: simple-server-app

You can use kubectl expose command to avoid mistakes like this.