Containers not accessible via container name , running in single pod(multi-container)

[neetra]

Problem: I have two applications say applicationA, applicationB.

Using Docker compose.yml: version: '3.4'

services:
  applicationa:
    environment:
      - ASPNETCORE_ENVIRONMENT=Development  

    ports:
      - "7001:80"  
  applicationb:
    environment:
      - ASPNETCORE_ENVIRONMENT=Development      

In dockerfile of applicationa (Exposed port 80), applicationb(exposed port 5000) Exposed port of applicationB is not mapped to external port thus it is not accessible directly ApplicationA access applicationB via http://containername:containerexposedport i.e http://applicationb:5000

Using Minikube: Deployment.yaml apiVersion: apps/v1 kind: Deployment metadata: name: appaappb-deployment labels: app: appaappb spec: replicas: 1 selector: matchLabels: app: appaappb template: metadata: labels: app: appaappb spec: containers:

• name: appa image: appa:latest env:
  • name: ASPNETCORE_ENVIRONMENT value: "Development" ports:
  • containerPort: 80
    imagePullPolicy: Never containers:
• name: appb image: appb:latest env:
  • name: ASPNETCORE_ENVIRONMENT value: "Development" ports:
  • containerPort: 5000
    imagePullPolicy: Never

Service (Map external port)

kubectl expose pod appaappb-deployment-8656cfcdff-wd4hv --name=appaappbservice --type="NodePort" --target-port 80 --port 80

Now as appA and appB are not in same docker network appA cannot access appB via container name and container internal port

So how to access appB in appA ?

information:

Minikube version:v1.9.2 Docker version: 19.0.3

[moshevayner]

Hey @neetra If both containers are running in the same pod (as in the example you specified), that means that they share the same IP address. So if appA needs to interact with appB, you should just use local host (127.0.0.1 and the relevant port 5000). Give that a try and let me know if that doesn’t work. Good luck!

[neetra]

@MoShitrit thanks for the response, but I am aware about this I want to know if there is any way to access?

[moshevayner]

Hey @neetra So backing up, I just want to make sure I understand the issue correctly. By access- do you mean that you wish to access appB directly using a service, and not sure how to do that? If that's the case, then all you have to do is either add another port to your existing service (kubectl edit service appaappbservice) and under spec.ports just add another object for appB, like this for example:

  - name: appB
    port: 5000
    protocol: TCP
    targetPort: 5000

Or, you can also create an additional service by running the same expose command you specified earlier, only give it a different name and a different targetPort, like this: kubectl expose pod appaappb-deployment-8656cfcdff-wd4hv --name=appbservice --type="NodePort" --target-port 5000 --port 5000

Another thing to bare in mind- once the service is updated, you'll need to find the actual node port that k8s allocated to your service, since (unless you configured it differently) the default range is a higher-number port, between 30000-32767, so you'll need to run kubectl get svc appaappbservice and get the mapping between the ports (i.e. you'll see something like that:

$ kubectl get svc appaappbservice
NAME              TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
appaappbservice   NodePort   100.71.239.74   <none>        80:32588/TCP   610d

In the above example, you'll need to access your minikube instance using port 32588.

[moshevayner]

Hey, @neetra ! I was just curious if you had a chance to try that yet? Is everything good now?

[fejta-bot]

Issues go stale after 90d of inactivity. Mark the issue as fresh with /remove-lifecycle stale. Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta. /lifecycle stale

[moshevayner]

/close

[k8s-ci-robot]

@MoShitrit: Closing this issue.

In response to [this](https://github.com/kubernetes/examples/issues/377#issuecomment-681077835): >/close Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes/test-infra](https://github.com/kubernetes/test-infra/issues/new?title=Prow%20issue:) repository.