K
Q

Naming a service in Kubernetes prevents it from starting

10/18/2019

Here is an example of yaml file for deploying:

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress
spec:
  backend:
    serviceName: gateway-service
    servicePort: 4001
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: gateway-deployment
spec:
  selector:
    matchLabels:
      app: gateway
  replicas: 2
  template:
    metadata:
      labels:
        app: gateway
    spec:
      containers:
      - name: gateway
        image: hello-go-microservices_gateway
        imagePullPolicy: Never
        ports:
        - containerPort: 4001
          protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: gateway-service
spec:
  selector:
    app: gateway
  ports:
  - protocol: TCP
    port: 4001
    targetPort: 4001
    nodePort: 30001
  type: NodePort

As you can see, the service is called gateway-service. The problem is when I rename it to just gateway, it's pods won't start. When I rename it to gateway-service back, or rename it to gateway1, or to gateway-blablabla, everytging works well.

Kubectl's logs show:

Failed to decode: strconv.ParseInt: parsing "tcp://10.101.177.91:4001": invalid syntax
-- ligowsky
kubectl
kubernetes
yaml

Similar Questions

How install Ceph on a kubernetes cluster
Failed to join Apache Ignite topology when multiple server pods starts at the same time
Kubernetes ftp deploy simple example
All containers showing ready, but pod is not ready
app in its own namespace with a service account available in any namespace
How to configure Horizontal Pod Autoscaler to fit pods to a node?
Drone Kubernetes Runner appending CA Certificate

3 Answers

10/18/2019

I finally figured out. Thanks to P Ekambaram's comment "some issue with the pod. are you using service name in pod?"

The issue was with .env file

GATEWAY_PORT=4001

It is for local development purpose. I renamed it to LOCAL_GATEWAY_PORT and now pods work with service named "gateway".

-- ligowsky
Source: StackOverflow
10/18/2019

Try below YAML. it should work

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress
spec:
  backend:
    serviceName: gateway
    servicePort: 4001
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: gateway-deployment
spec:
  selector:
    matchLabels:
      app: gateway
  replicas: 2
  template:
    metadata:
      labels:
        app: gateway
    spec:
      containers:
      - name: gateway
        image: hello-go-microservices_gateway
        imagePullPolicy: Never
        ports:
        - containerPort: 4001
          protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: gateway
spec:
  selector:
    app: gateway
  ports:
  - protocol: TCP
    port: 4001
    targetPort: 4001
    nodePort: 30001
  type: NodePort

i just deployed deployment and service. it worked without any issues

master $ kubectl get po,svc | grep gateway

pod/gateway-deployment-6549f895b4-5d9kj   1/1     Running   0          18s
pod/gateway-deployment-6549f895b4-vzqj6   1/1     Running   0          18s
service/gateway      NodePort    10.106.132.46   <none>        4001:30001/TCP   18s
master $ curl 10.106.132.46:4001
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
-- P Ekambaram
Source: StackOverflow
10/18/2019

Thanks to P Ekambaram suggestion and just to provide more information for other community members in case they will have the same issue:

According to the Discovering services mechanism - once the service was created all information where applied to the PODS env:

Note:

When a Pod is run on a Node, the kubelet adds a set of environment variables for each active Service. It supports both Docker links compatible variables (see makeLinkVariables) and simpler {SVCNAME}_SERVICE_HOST and {SVCNAME}_SERVICE_PORT variables, where the Service name is upper-cased and dashes are converted to underscores.

Proper env variables should looks like:

GATEWAY_PORT_8080_TCP=tcp://10.4.13.154:8080
GATEWAY_PORT_8080_TCP_PROTO=tcp
GATEWAY_PORT_8080_TCP_PORT=8080
GATEWAY_PORT_8080_TCP_ADDR=10.4.13.154

GATEWAY_SERVICE_HOST=10.4.13.154
GATEWAY_SERVICE_PORT=8080

and values for: GATEWAY_PORT=tcp://10.4.13.154:8080 were overridden by your custom settings:

 GATEWAY_PORT=8080
-- Hanx
Source: StackOverflow