Minikube expose MySQL running on localhost as service

Question

I have minikube version v0.17.1 running on my machine. I want to simulate the environment I will have in AWS, where my MySQL instance will be outside of my Kubernetes cluster.

Basically, how can I expose my local MySQL instance running on my machine to the Kubernetes cluster running via minikube?

Answer 1

Kubernetes allows you to create a service without selector, and cluster will not create related endpoint for this service, this feature is usually used to proxy a legacy component or an outside component.

1. Create a service without selector

   apiVersion: v1
   kind: Service
   metadata:
       name: my-service
   spec:
       ports:
           - protocol: TCP
             port: 1443
             targetPort: <YOUR_MYSQL_PORT>
   

2. Create a relative Endpoint object

   apiVersion: v1
   kind: Endpoints
   metadata:
       name: my-service
   subsets:
       - addresses:
           - ip: <YOUR_MYSQL_ADDR>
         ports:
           - port: <YOUR_MYSQL_PORT>
   

3. Get service IP

   $ kubectl get svc my-service
   NAME         CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE
   my-service   <SERVICE_IP>   <none>        1443/TCP    18m
   

4. Access your MYSQL from service <SERVICE_IP>:1443 or my-service:1443

Answer 2

As of minikube 1.10, there is a special hostname host.minikube.internal that resolves to the host running the minikube VM or container. You can then configure this hostname in your pod's environment variables or the ConfigMap that defines the relevant settings.

Answer 3

Option 1 - use a headless service without selectors

Because this service has no selector, the corresponding Endpoints object will not be created. You can manually map the service to your own specific endpoints (See doc).

kind: Service
apiVersion: v1
metadata:
  name: my-service
spec:
  ports:
  - port: 80
    targetPort: 8080
---
kind: Endpoints
apiVersion: v1
metadata:
  name: my-service
subsets:
- addresses:
  - ip: 10.0.2.2
  ports:
  - port: 8080

---

Option 2 - use ExternalName service

kind: Service
apiVersion: v1
metadata:
  name: my-service
spec:
  type: ExternalName
  externalName: minikube.host

The only caveat is that it needs to be able to resolve minikube.host. Simply add this line to the etc/hosts file should do it.

10.0.2.2        minikube.host

ExternalName doesn't support port mapping at the moment.

---

Another note: The IP 10.0.2.2 is known to work with Virtual Box only (see SO). For xhyve, try replacing that with 192.168.99.1 (see GitHub issue and issue). A demo GitHub.

Answer 4

Just a reminder, if on Windows, open your firewall.