Can't connect to mysql service on kuberenetes through workbench - docker

Question

I am using Minikube and here is my configuration:
kubectl describe deployment mysql
the output:
Name: mysql
Namespace: default
CreationTimestamp: Sat, 12 Nov 2022 02:20:54 +0200
Labels: <none>
Annotations: deployment.kubernetes.io/revision: 1
Selector: app=mysql
Replicas: 1 desired | 1 updated | 1 total | 1 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=mysql
Containers:
mysql:
Image: mysql
Port: 3306/TCP
Host Port: 0/TCP
Environment:
MYSQL_ROOT_PASSWORD: <set to the key 'password' in secret 'mysql-pass'> Optional: false
Mounts:
/docker-entrypoint-initdb.d from mysql-init (rw)
Volumes:
mysql-init:
Type: ConfigMap (a volume populated by a ConfigMap)
Name: mysql-init
Optional: false
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: mysql-77fd55bbd9 (1/1 replicas created)
when I try to connect to it using mysql workbench:
it shows me:
However, when I execute this line to create a mysql-client to try to connect to mysql server:
kubectl run -it --rm --image=mysql:8.0 --restart=Never mysql-client -- mysql -h mysql -u skaffold -p
and then enter the password, it works well! but still I need to use workbench better.
any help please?
edit 1:
Here is the yaml file for the deployment and the service:
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: mysql
spec:
replicas: 1
selector:
matchLabels:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
containers:
- name: mysql
image: mysql
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-pass
key: password
ports:
- containerPort: 3306
volumeMounts:
- name: mysql-init
mountPath: /docker-entrypoint-initdb.d
volumes:
- name: mysql-init
configMap:
name: mysql-init
---
apiVersion: v1
kind: Service
metadata:
name: mysql
labels:
name: mysql
spec:
ports:
- port: 3306
targetPort: 3306
protocol: TCP
selector:
app: mysql

Answer 1

First make sure your service is running, so
kubectl get service
should return something like :
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
mysql ClusterIP 10.99.140.115 <none> 3306/TCP 2d6h
From that point onwards, I'd try running a port-forward first :
kubectl port-forward service/mysql 3306:3306
This should allow you to connect even when using a ClusterIP service.

Answer 2

If you want to connect directly to your mysql Deployment's Pod via localhost, first, you have to forward a Pod's container port to the localhost.
kubectl port-forward <pod-name> <local-port>:<container-port>
Then your mysql will be accessible on localhost:<local-port>.
The other way to communicate with your Pod is created a Service object that will pass your requests directly to the Pod. There are couple type of Services for different types of usage. Check the documentation to learn more.
The reason the following command
kubectl run -it --rm --image=mysql:8.0 --restart=Never mysql-client -- mysql -h mysql -u skaffold -p
connects to the database correctly is because the connect command is done inside the mysql container itself.
Edit 1
If you not specified the type of Service, the default is going to be ClusterIP which not allow you to expose port outside the cluster.
Because Minikube doesn't handle LoadBalancer use NodePort Service type instead.
Your Service YAML manifest should look like this:
apiVersion: v1
kind: Service
metadata:
name: mysql
labels:
name: mysql
spec:
type: NodePort
ports:
- port: 3306
targetPort: 3306
protocol: TCP
selector:
app: mysql
Finally, therefore your cluster is provisioned via Minikube, you still need to call the command below for fetch the Minikube IP and a Service’s NodePort:
minikube service <service-name> --url