mysql service pending in kubernetes - mysql

Question

I created .yaml file to create mysql service on kubernetes for my internal application, but it's unreachable. I can reach application and also phpmyadmin to reach database but it's not working properly. I'm stuck with pending status on mysql pod.
.yaml file:
apiVersion: apps/v1
kind: Deployment
metadata:
name: mysql
namespace: cust
labels:
app: db
spec:
replicas: 1
selector:
matchLabels:
app: db
template:
metadata:
labels:
app: db
spec:
containers:
- name: mysql
image: mysql
imagePullPolicy: Never
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: flaskapi-cred
key: db_root_password
ports:
- containerPort: 3306
name: db-container
volumeMounts:
- name: mysql-persistent-storage
mountPath: /var/lib/mysql
volumes:
- name: mysql-persistent-storage
persistentVolumeClaim:
claimName: mysql-pv-claim
---
apiVersion: v1
kind: Service
metadata:
name: mysql
namespace: cust
labels:
app: db
spec:
ports:
- port: 3306
protocol: TCP
name: mysql
selector:
app: db
type: LoadBalancer
kubectl get all output is:
NAME READY STATUS RESTARTS AGE
pod/flaskapi-deployment-59bcb745ff-gl8xn 1/1 Running 0 117s
pod/mysql-99fb77bf4-sbhlj 0/1 Pending 0 118s
pod/phpmyadmin-deployment-5fc964bf9d-dk59t 1/1 Running 0 118s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/flaskapi-deployment 1/1 1 1 117s
deployment.apps/mysql 0/1 1 0 118s
deployment.apps/phpmyadmin-deployment 1/1 1 1 118s
I already did docker pull mysql.
Edit
Name: mysql-99fb77bf4-sbhlj
Namespace: z2
Priority: 0
Node: <none>
Labels: app=db
pod-template-hash=99fb77bf4
Annotations: <none>
Status: Pending
IP:
IPs: <none>
Controlled By: ReplicaSet/mysql-99fb77bf4
Containers:
mysql:
Image: mysql
Port: 3306/TCP
Host Port: 0/TCP
Environment:
MYSQL_ROOT_PASSWORD: <set to the key 'db_root_password' in secret 'flaskapi-secrets'> Optional: false
Mounts:
/var/lib/mysql from mysql-persistent-storage (rw)
/var/run/secrets/kubernetes.io/serviceaccount from default-token-gmbnd (ro)
Conditions:
Type Status
PodScheduled False
Volumes:
mysql-persistent-storage:
Type: PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
ClaimName: mysql-pv-claim
ReadOnly: false
default-token-gmbnd:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-gmbnd
Optional: false
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning FailedScheduling 3m44s default-scheduler persistentvolumeclaim "mysql-pv-claim" not found
Warning FailedScheduling 3m44s default-scheduler persistentvolumeclaim "mysql-pv-claim" not found

Answer 1

you are missing the volume to attach with the pod or deployment. PVC is required as your deployment configuration is using it.
you can see clearly : persistentvolumeclaim "mysql-pv-claim" not found
you can apply below YAML and try.
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-pv-volume
labels:
type: local
spec:
storageClassName: manual
capacity:
storage: 20Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/mnt/data"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mysql-pv-claim
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 20Gi

Answer 2

As the error in the message clearly shows persistentvolumeclaim "mysql-pv-claim" not found. So you need to provision a persistentvolumeclaim (PVC).
There is a static & dynamic provisioning but I'll explain static provisioning here as it will be relatively easy for you to understand & setup. You need to create a PersistentVolume (PV) which the PVC will use. There are various types of Volumes, about which you read here.
Which type of Volume you would wanna create would be your choice depending on your environment and needs. A simple example would be of volume type hostPath.
Create a PV:
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-pv-volume
namespace: cust
labels:
type: local
spec:
storageClassName: manual
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
hostPath:
# The configuration here specifies that the volume is at /tmp/data on the cluster's Node
path: "/tmp/data"
And then create a PVC:
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mysql-pv-claim
namespace: cust
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
volumeName: mysql-pv-volume
Once the PVC is successfully created, your deployment shall go through.