Minikube: akses apps
Sumber: https://minikube.sigs.k8s.io/docs/handbook/accessing/
How to access applications running within minikube
There are two major categories of services in Kubernetes:
Berikut adalah cara mengakses aplikasi yang berjalan di dalam minikube. Ada dua kategori utama layanan di Kubernetes:
- NodePort
- LoadBalancer
minikube mendukung ke dua-nya.
NodePort access
NodePort service adalah cara paling dasar untuk mendapatkan lalu lintas eksternal langsung ke service tersebit. NodePort, seperti namanya, membuka port tertentu, dan lalu lintas apa pun yang dikirim ke port ini diteruskan ke service yang dimaksud.
Getting the NodePort using the service command
We also have a shortcut for fetching the minikube IP and a service’s NodePort:
minikube service <service-name> --url
Using minikube service with tunnel
The network is limited if using the Docker driver on Darwin, Windows, or WSL, and the Node IP is not reachable directly.
Running minikube on Linux with the Docker driver will result in no tunnel being created.
Services of type NodePort can be exposed via the
minikube service <service-name> --url
command. It must be run in a separate terminal window to keep the tunnel open. Ctrl-C in the terminal can be used to terminate the process at which time the network routes will be cleaned up.
Example of NodePort
Create a Kubernetes deployment
kubectl create deployment hello-minikube1 --image=kicbase/echo-server:1.0
Create a Kubernetes service type NodePort
kubectl expose deployment hello-minikube1 --type=NodePort --port=8080
Check Node Port
$ kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE hello-minikube1 NodePort 10.100.238.34 <none> 8080:31389/TCP 3s
Run service tunnel
minikube service hello-minikube1 --url minikube service hello-minikube1 --url runs as a process, creating a tunnel to the cluster. The command exposes the service directly to any program running on the host operating system.
service output example Check ssh tunnel in another terminal
$ ps -ef | grep docker@127.0.0.1 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -N docker@127.0.0.1 -p 55972 -i /Users/FOO/.minikube/machines/minikube/id_rsa -L TUNNEL_PORT:CLUSTER_IP:TARGET_PORT
Try in your browser
Open in your browser (ensure there is no proxy set)
http://127.0.0.1:TUNNEL_PORT
Getting the NodePort using kubectl
The minikube VM is exposed to the host system via a host-only IP address, that can be obtained with the minikube ip command. Any services of type NodePort can be accessed over that IP address, on the NodePort.
To determine the NodePort for your service, you can use a kubectl command like this (note that nodePort begins with lowercase n in JSON output):
kubectl get service <service-name> --output='jsonpath="{.spec.ports[0].nodePort}"'
Increasing the NodePort range
By default, minikube only exposes ports 30000-32767. If this does not work for you, you can adjust the range by using:
minikube start --extra-config=apiserver.service-node-port-range=1-65535
This flag also accepts a comma separated list of ports and port ranges.
LoadBalancer access
A LoadBalancer service is the standard way to expose a service to the internet. With this method, each service gets its own IP address.
Using minikube tunnel
Services of type LoadBalancer can be exposed via the minikube tunnel command. It must be run in a separate terminal window to keep the LoadBalancer running. Ctrl-C in the terminal can be used to terminate the process at which time the network routes will be cleaned up.
Example of LoadBalancer
Run the tunnel in a separate terminal
It will ask for a password.
minikube tunnel
minikube tunnel runs as a process, creating a network route on the host to the service CIDR of the cluster using the cluster’s IP address as a gateway. The tunnel command exposes the external IP directly to any program running on the host operating system.
tunnel output example Create a Kubernetes deployment
kubectl create deployment hello-minikube1 --image=kicbase/echo-server:1.0
Create a Kubernetes service with type LoadBalancer
kubectl expose deployment hello-minikube1 --type=LoadBalancer --port=8080
Check the external IP
kubectl get svc $ kc get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE hello-minikube1 LoadBalancer 10.96.184.178 10.96.184.178 8080:30791/TCP 40s
Note that without minikube tunnel, Kubernetes will show the external IP as “pending”.
Try in your browser
Open in your browser (ensure there is no proxy set)
http://REPLACE_WITH_EXTERNAL_IP:8080
Each service will get its own external IP.
DNS resolution (experimental)
If you are on macOS, the tunnel command also allows DNS resolution for Kubernetes services from the host.
NOTE: docker driver doesn’t support DNS resolution
Cleaning up orphaned routes
If the minikube tunnel shuts down in an abrupt manner, it may leave orphaned network routes on your system. If this happens, the ~/.minikube/tunnels.json file will contain an entry for that tunnel. To remove orphaned routes, run:
minikube tunnel --cleanup
NOTE: --cleanup flag’s default value is true.
Avoiding password prompts
Adding a route requires root privileges for the user, and thus there are differences in how to run minikube tunnel depending on the OS. If you want to avoid entering the root password, consider setting NOPASSWD for “ip” and “route” commands:
https://superuser.com/questions/1328452/sudoers-nopasswd-for-single-executable-but-allowing-others
Access to ports <1024 on Windows requires root permission
If you are using Docker driver on Windows, there is a chance that you have an old version of SSH client you might get an error like - Privileged ports can only be forwarded by root. or you might not be able to access the service even after minikube tunnel if the access port is less than 1024 but for ports greater than 1024 works fine.
In order to resolve this, ensure that you are running the latest version of SSH client. You can install the latest version of the SSH client on Windows by running the following in a Command Prompt with an Administrator Privileges (Requires chocolatey package manager)
choco install openssh
The latest version (OpenSSH_for_Windows_7.7p1, LibreSSL 2.6.5) which is available on Windows 10 by default doesn’t work. You can track the issue with this over here - https://github.com/PowerShell/Win32-OpenSSH/issues/1693