Start: 2023-01-25 21:40:07
Finished: 2023-01-25 23:20:05
One of the Nautilus DevOps team members was working on to update an existing Kubernetes template. Somehow, he made some mistakes in the template and it is failing while applying. We need to fix this as soon as possible, so take a look into it and make sure you are able to apply it without any issues. Also, do not remove any component from the template like pods/deployments/volumes etc.
/home/thor/mysql_deployment.yml is the template that needs to be fixed.
Note: The kubectl utility on jump_host has been configured to work with the kubernetes cluster.
The deployment is still not deployed so we don't any logs to inspect. The quickest step to do is to try to deploy it and watch for any error messages.
$ kubectl apply -f mysql_deployment.yml
unable to recognize "mysql_deployment.yml": no matches for kind "PersistentVolume" in version "apps/v1"
unable to recognize "mysql_deployment.yml": no matches for kind "PersistentVolumeClaim" in version "apps/v1"
error validating "mysql_deployment.yml": error validating data: ValidationError(Service.spec): unknown field "tier" in io.k8s.api.core.v1.ServiceSpec; if you choose to ignore these errors, turn validation off with --validate=false Now that we have an error message, we can now try to check the manifest.
mysql_deployment.yml
apiVersion: apps/v1
kind: PersistentVolume
metadata:
name: mysql-pv
labels:
type: local
spec:
storageClassName: standard
capacity:
storage: 250Mi
accessModes:
- ReadWriteOnce
hostPath:
path: "/mnt/data"
persistentVolumeReclaimPolicy:
- Retain
---
apiVersion: apps/v1
kind: PersistentVolumeClaim
metadata:
name: mysql-pv-claim
labels:
app: mysql-app
spec:
storageClassName: standard
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 250MB
---
apiVersion: v1
kind: Service
metadata:
name: mysql
labels:
app: mysql-app
spec:
type: NodePort
ports:
- targetPort: 3306
port: 3306
nodePort: 30011
selector:
app: mysql-app
tier: mysql
---
apiVersion: v1
kind: Deployment
metadata:
name: mysql-deployment
labels:
app: mysql-app
spec:
selector:
matchLabels:
app: mysql-app
tier: mysql
strategy:
type: Recreate
template:
metadata:
labels:
app: mysql-app
tier: mysql
spec:
containers:
- images: mysql:5.6
name: mysql
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-root-pass
key: password
- name: MYSQL_DATABASE
valueFrom:
secretKeyRef:
name: mysql-db-url
key: database
- name: MYSQL_USER
valueFrom:
secretKeyRef:
name: mysql-user-pass
key: username
- name: MYSQL_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-user-pass
key: password
ports:
- containerPort: 3306
name: mysql
volumeMounts:
- name: mysql-pv
mountPath: /var/lib/mysql
volumes:
- name: mysql-pv
persistentVolumeClaim:
claimName: mysql-pv-claim Since the manifest uses secrets that are injected as environment variables, we have to check the secrets already created.
$ kubectl get secrets
NAME TYPE DATA AGE
default-token-24vjd kubernetes.io/service-account-token 3 77m
mysql-db-url Opaque 1 12m
mysql-root-pass Opaque 1 12m
mysql-user-pass Opaque 2 12m Since there's no requirement to break down the manifest into the separate spec file for each resource, we can just fix the provided YAML file.
- "tier: mysql" needs to be indented
- "mysql-pv" should be the persistent volume name
- "app: mysql-app" under PVC should be indented
- "type: local" under PV should be indented
- "apps/v1" under PV and PVC should be "v1"
- "path: "/mnt/data"" under PV should be indented
- "persistentVolumeReclaimPolicy" under PV should have a string value
- "storage: 250MB" uNDER PVC should be 250Mi
- attributes under "volumes" under Deployment should have the correct indentation
- "claimName: mysql-pv-claim" under Deployment should be indented
- "images: mysql:5.6" under Deployment should be "image"
The fixed manifest should now look like this:
mysql_deployment.yml
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-pv
labels:
type: local
spec:
storageClassName: standard
capacity:
storage: 250Mi
accessModes:
- ReadWriteOnce
hostPath:
path: "/mnt/data"
persistentVolumeReclaimPolicy: Retain
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mysql-pv-claim
labels:
app: mysql-app
spec:
storageClassName: standard
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 250Mi
---
apiVersion: v1
kind: Service
metadata:
name: mysql
labels:
app: mysql-app
spec:
type: NodePort
ports:
- targetPort: 3306
port: 3306
nodePort: 30011
selector:
app: mysql-app
tier: mysql
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: mysql-deployment
labels:
app: mysql-app
spec:
selector:
matchLabels:
app: mysql-app
tier: mysql
strategy :
type: Recreate
template:
metadata:
labels:
app: mysql-app
tier: mysql
spec:
containers:
- image: mysql:5.6
name: mysql
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-root-pass
key: password
- name: MYSQL_DATABASE
valueFrom:
secretKeyRef:
name: mysql-db-url
key: database
- name: MYSQL_USER
valueFrom:
secretKeyRef:
name: mysql-user-pass
key: username
- name: MYSQL_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-user-pass
key: password
ports:
- containerPort: 3306
name: mysql
volumeMounts:
- name: mysql-persistent-storage
mountPath: /var/lib/mysql
volumes:
- name: mysql-persistent-storage
persistentVolumeClaim:
claimName: mysql-pv-claimApply:
kubectl apply -f . Check the resources.
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
mysql-deployment-567f75bfc-pt885 1/1 Running 0 2m31s
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 19m
mysql NodePort 10.96.0.75 <none> 3306:30011/TCP 2m38s
$ kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
mysql-pv 250Mi RWO Retain Bound default/mysql-pv-claim standard 5m32s
$ kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
mysql-pv-claim Bound mysql-pv 250Mi RWO standard 5m37s We could check the logs to ensure the MySQL deployment is running.
$ kubectl logs -f deployment/mysql-deployment
2023-01-25 14:47:50+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.6.51-1debian9 started.
2023-01-25 14:47:51+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2023-01-25 14:47:51+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.6.51-1debian9 started.
2023-01-25 14:47:51+00:00 [Note] [Entrypoint]: Initializing database files
2023-01-25 14:47:51 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).