From my local machine I would like to be able to port forward to many services in a cluster. For example I have services of name serviceA-type1, serviceA-type2, serviceA-type3 ... etc. None of these services are accessible externally but can be accessed using the kubectl port-forward command. However there are so many services, that port forwarding to each is unfeasible.
Is it possible to create some kind of proxy service in kubernetes that would allow me to connect to any of the serviceA-typeN services by specifying the them in a URL? I would like to be able to port-forward to the proxy service from my local machine and it would then forward the requests to the serviceA-typeN services.
So for example, if I have set up a port forward on 8080 to this proxy, then the URL to access the serviceA-type1 service might look like:
http://localhost:8080/serviceA-type1/path/to/endpoint?a=1 etc.
I could maybe create a small application that would do this but does kubernetes provide this functionality already?
CodePudding user response：
kubectl proxy command provides this functionality.
Read more here: https://kubernetes.io/docs/tasks/administer-cluster/access-cluster-services/#manually-constructing-apiserver-proxy-urls
CodePudding user response：
Good option is to use Ingrees to achieve it.
Read more about what Ingress is.
Main concepts are:
- Ingress exposes HTTP and HTTPS routes from outside the cluster to services within the cluster. Traffic routing is controlled by rules defined on the Ingress resource.
- An Ingress may be configured to give Services externally-reachable URLs, load balance traffic, terminate SSL / TLS, and offer name-based virtual hosting.
- An Ingress controller is responsible for fulfilling the Ingress, usually with a load balancer, though it may also configure your edge router or additional frontends to help handle the traffic.
- An Ingress does not expose arbitrary ports or protocols. Exposing services other than HTTP and HTTPS to the internet typically uses a service of type
Service.Type=NodePortorService.Type=LoadBalancer.
In Kubernetes we have 4 types of Services and the default service type is Cluster IP which means the service is only reachable within the cluster.Ingress exposes your service outside the cluster so ingress acts as the entry point into your cluster.
If you plan to move to cloud (I assume you will, because all applications are going to work in cloud in future) with Ingress, it will be compatible with cloud services and eventually will save time and will be easier to migrate from local environment.
To start with ingress you need to install an Ingress controller first.
There are different ingress controllers which you can use.
You can start with most common ingress-nginx which is supported by kubernetes community.
If you're using a minikube than it can be enabled as an addon - see here
Once you have installed ingress in your cluster, you need to create a rule to have it work. Simple fanout is an example with two services and path based routing to it.