Skip to content

Latest commit

 

History

History
121 lines (91 loc) · 4.69 KB

port-forwarding.md

File metadata and controls

121 lines (91 loc) · 4.69 KB
Raw

port-forwarding

When working with Kubernetes it is often required to connect to services running on your nodes without exposing those services to the internet. We accomplish this using Kubernetes Config files, and the kubectl port-forward command.

Let's give that a try!

Here's a guide of how to connect to your Azure Kubernetes Cluster(AKS) once its deployed and Port Forward

Here's a guide of how to connect to your Google Kubernetes Cluster(GKE) once its deployed and Port Forward

Here's a guide of how to connect to your Amazon Kubernetes Cluster(EKS) once its deployed and Port Forward

Below is a guide of how to connect to your unmanaged Amazon Kubernetes Cluster(aws)

1. Login to node using cloud console:

Open the cloud console and visit the page that lists your running virtual machines, in AWS this is the EC2 Instances page (the region parameter of this url must be updated if your instances are not in us-east-1).

Click on the node id link in the UI for your leader, then click Connect in the top right. Copy the "Public IP address" value and paste it in a note for yourself. We will need it later to connect to our node remotely. Type "ubuntu" into the User name field, and click Connect.

2. Retrieve Kubernetes config:

When you have a prompt available to you, enter the following command to retrieve the Kubernetes config for your microk8s cluster:

microk8s config

This will give you a great big blob of yaml. Consider this your key to access the cluster from the outside of the cloud. With it on your machine you will be able to talk to the Kubernetes control plane.

apiVersion: v1
clusters:
- cluster:
    certificate-authority-data:
    dNPUHFObk9utNxN5cNI3T2bWF...PQotLS0tLLUVORCtLS0tCgBDRVJUSUZJQ0FURS0==
    server: https://173.31.90.189:16443 # the IP address provided here is typically the private IP of the Kubernetes controller. We need to update this to the public IP of the controller so we can access it from outside of the node's network. The port should stay as "16443" and the scheme as "https://".
  name: microk8s-cluster
contexts:
- context:
    cluster: microk8s-cluster
    user: admin
  name: microk8s
current-context: microk8s
kind: Config
preferences: {}
users:
- name: admin
  user:
    token: dnQmY3lJz...3Y4ODo3c2MwN0ltT1R

3. Update IP Address in Kubernetes Config:

You want to take this yaml blob to a text editor and replace the IP address listed and replace it with the public IP address of your leader node that you copied just before connecting. If you don't change the IP address it will be set to the Private IP of the node, and we can't connect to the private IP from outside of the cloud.

4. Add Kubernetes config to your work station:

Next you want to take that text with the newly set Public IP, and put it in your kubernetes config file, which is probably located at ~/.kube/config. You can merge your configs, but if you are new to this you can just delete the contents of that default config file file and replace them with our yaml.

5. Port Forwarding a Service:

Port forwarding a service is the same process no matter which service you are forwarding, there are just a couple variables. Let's examine this process for ArgoCD, because it will be running on every CNDI cluster, but this applies equally to any other service.

We need to know the namespace of the service, the service name, the exposed port and the desired port. Let's see what we can find out about the services argo is running now that we have setup control plane access in the last step.

# TODO: find a way to avoid this flag if possible without a custom domain name
kubectl get svc --namespace argocd --insecure-skip-tls-verify

We can now see that in our Kubernetes cluster we have a number of Argo services running in the argocd namespace. The one we want is argocd-server running on ports 80 and 443.

Let's forward the application running on port 80 to our local machine.

kubectl port-forward svc/argocd-server --namespace argocd :80

You will see a message similar to:

Forwarding from 127.0.0.1:50445 -> 8080

Let's open the port displayed in the browser:

eg: http:https://127.0.0.1:50445

You should now see a login page for argo, and a place to enter a username and password. The username is admin and the password is available in the .env file we created for you under the key ARGOCD_ADMIN_PASSWORD.