I'm using lxc/lxd to play with the kubenetes cluster.
Is there a way to expose a deployed service locally without using minikube, so that I could access it from the local machine?
I can access it from any of the nodes in the cluster but not from outside.
Do you want to acccess the pod being served by the service? if yes, you can use kubectl port-forward to connect to your pod and access it locally
Here is an example:
If you have a service which forwards all the requests to a pod ( nginx ) at port number 80 you can configure it to your local port as follows
kubectl port-forward -n default nginx-5767f4d585-hgtfj 8081:80
Here is the syntax of the same
kubectl port-forward -n NAMESPACE ${POD} local-port:pod-port
If you want to connect to your service directly, you need to do it via kubectl proxy
Here is a reference
Hope it helps.
Related
I have a deployment with services running inside minikube on a remote linux vps, these services have Cluster IP with no external IP, I would want to access these services from a web browser
Either you change the service type LoadBalancer which will create the External for you and you can access the specific service using that.
OR
Setup the ingress and ingress controller which can be also useful to expose the service directly.
OR for just Development use not for Prod
kubectl port-forward svc/<service name> 5555:<service port here>
This creates the proxy tunnel between your K8s cluster and local. You can access your service now at localhost:5555
I am working on rancher server, k3s to improve my knowledge on these solutions.
I want to expose container services on LAN network, this is why I used kubectl port-forward.
kubectl port-forward --namespace=ns-name --address LAN-IP service/hello 30104:8080
But I can see in several web resources that is not a reliable solution, just for local testing purpose.
I tried to replace them by ingress but I am a bit lost between ingress, DNS and nginx-ingress in addition to rancher component.
I understood than load balancer need a cloud provider, to have a public IP for instance, and handle the <pending> state of load balancer.
Can you highlight me on how replace port-forward in LAN without a cloud provider?
[edit #Rajesh Dutta]
I already use NodePort, but, without port-forward the service is exposed as NODE_IP:PORT, not LAN_IP:PORT. My need is to join it from outside of the cluster.
So this is what i did :
1 - create deployment
kubectl create deployment hello --image=gcr.io/google-samples/node-hello:1.0 --port=8080 --replicas=2
2 - expose deployment(create service)
kubectl expose deployment hello --type=NodePort
3 - forward service
kubectl port-forward --namespace=ns-name --address local-ip service/hello 30104:8080
IP schema
Now, considering that i will have several service, i would find the best ways to replace port-forward.
To start with I would recommend to use NodePort service. This will expose your application to a NodePort(30000-32767). Later if you want you can choose to switch to ingress.
Assuming that you are trying with a deployment type object
command:
kubectl expose deployment deployment-name --type=NodePort --port=8080 --target-port=<rancher server port>
Hi I'm really new in kubernetes and I'm playing around with minikube and deployed a nginx server successfully, executing minikube ip I'm able to get the deployed application ip and access to it via browser or give it an alias in hosts file.
And now I'm playing around with k3d and I noticed that there is no equivalent command to get that ip for my nginx deployed application, how can I get that ip?
You can retrieve the exposed IP on the traefik service (on the kube-system namespace)
kubectl get -n kube-system service/traefik -o jsonpath="{.status.loadBalancer.ingress[0].ip}"
Whats the difference between kubectl port-forwarding (which forwards port from local host to the pod in the cluster to gain access to cluster resources) and NodePort Service type ?
You are comparing two completely different things. You should compare ClusterIP, NodePort, LoadBalancer and Ingress.
The first and most important difference is that NodePort expose is persistent while by doing it using port-forwarding, you always have to run kubectl port-forward ... and kept it active.
kubectl port-forward is meant for testing, labs, troubleshooting and not for long term solutions. It will create a tunnel between your machine and kubernetes so this solution will serve demands from/to your machine.
NodePort can give you long term solution and it can serve demands from/to anywhere inside the network your nodes reside.
If you use port forwarding kubectl port forward svc/{your_service} -n {service_namespace} you just need a clusterIP, kubectl will handle the traffic for you. Kubectl will be the proxy for your traffic
If you use nodeport for access your service means you need to open port on the worker nodes.
when you use port forwarding, that is going to cause our cluster to essentially behave like it has a node port service running inside of it without creating a service. This is strictly for the development setting. with one command you will have a node port service.
// find the name of the pod that running nats streaming server
kubectl get pods
kubectl port-forward nats-Pod-5443532542c8-5mbw9 4222:4222
kubectl will set up proxy that will forward any trafic on your local machine to a port on that specific pod.
however, to create a node port you need to write a YAML config file to set up a service. It will expose the port permanently and performs load balancing.
kubectl proxy and kubectl port-forwarding look similar and confusing to me, what are their main differences and use cases?
As mentioned in "How kubectl port-forward works?"
kubectl port-forward forwards connections to a local port to a port on a pod.
Compared to kubectl proxy, kubectl port-forward is more generic as it can forward TCP traffic while kubectl proxy can only forward HTTP traffic.
As an example, see "Kubernetes port forwarding simple like never before" from Alex Barashkov:
Port forwarding mostly used for the purpose of getting access to internal cluster resources and debugging.
How does it work?
Generally speaking, using port forwarding you could get on your ‘localhost’ any services launched in your cluster.
For example, if you have Redis installed in the cluster on 6379, by using a command like this:
kubectl port-forward redis-master-765d459796-258hz 7000:6379
you could forward Redis from the cluster to localhost:7000, access it locally and do whatever you want to do with it.
For a limited HTTP access, see kubectl proxy, and, as an example, "On Securing the Kubernetes Dashboard" from Joe Beda:
The easiest and most common way to access the cluster is through kubectl proxy. This creates a local web server that securely proxies data to the dashboard through the Kubernetes API server.
As shown in "A Step-By-Step Guide To Install & Use Kubernetes Dashboard" from Awanish:
kubectl create -f https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml
Accessing Dashboard using the kubectl
kubectl proxy
It will proxy server between your machine and Kubernetes API server.
Now, to view the dashboard in the browser, navigate to the following address in the browser of your Master VM:
http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/