CreateContainerError while creating postgresql in k8s - postgresql

Question

I'm trying to run postgresql db at k8s and there is no errors while creating all from file, but pod at the deployment cant create container.
There is my yaml code:
ConfigMap:
apiVersion: v1
kind: ConfigMap
metadata:
name: postgres-config
labels:
app: postgres
data:
POSTGRES_DB: postgresdb
POSTGRES_USER: postgresadmin
POSTGRES_PASSWORD: adminpassword
Deployment:
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgres
spec:
replicas: 1
selector:
matchLabels:
app: postgres
template:
metadata:
labels:
app: postgres
spec:
containers:
- name: postgres
image: postgres:10.18
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 5432
envFrom:
- configMapRef:
name: postgres-config
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgredb
volumes:
- name: postgredb
persistentVolumeClaim:
claimName: postgres-pv-claim
Sevice:
apiVersion: v1
kind: Service
metadata:
name: postgres
labels:
app: postgres
spec:
type: ClusterIP
ports:
- port: 5432
selector:
app: postgres
after i'm using:
kubectl create -f filename
i got :
configmap/postgres-config created
persistentvolume/postgres-pv-volume created
persistentvolumeclaim/postgres-pv-claim created
deployment.apps/postgres created
service/postgres created
But when i'm typing:
kubectl get pods
There is an error:
postgres-78496cc865-85kt7 0/1 CreateContainerError 0 13m
this is PV and PVC, no more space at the question to ad that as a code :)

Answer 1

If you describe the pod, you'll see the warning message in there,
Warning FailedScheduling 45s (x2 over 45s) default-scheduler persistentvolumeclaim "postgres-pv-claim" not found
On a high level, a database instance can run within a Kubernetes container. A database instance stores data in files, and the files are stored in persistent volume claims. A PersistentVolumeClaim must be created and made available to a PostgreSQL instance.To create the database instance as a container, you use a deployment configuration. In order to provide an access interface that is independent of the particular container, you create a service that provides access to the database. The service remains unchanged even if a container (or pod) is moved to a different node.
In your case, create a PVC resource and bound it to PV so that will be used by the pod. As currently it does not found that , it went into pending state. This can be achieved in multiple ways, you can either use the hostPath as the local storage,
$ k get pods
NAME READY STATUS RESTARTS AGE
postgres-795cfcd67b-khfgn 1/1 Running 0 18s
Sample PV and PVC configs as below,
apiVersion: v1
kind: PersistentVolume
metadata:
name: pv-nautilus
spec:
storageClassName: manual
capacity:
storage: 8Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/home/mohan"
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: postgres-pv-claim
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
You can check the Persistent Volume doc for more details. Also, read more about storage class and StatefulSets for deploying database applications in Kubernetes cluster.

Answer 2

Thanks to all who tried to help me! Problem was at PersistentVolume.spec.hostPath.path. There was an invalid character at the path. I tried to use "./path".