In my Kubernetes cluster, on my DB container, my persistent storage (dynamically provisioned on Digital Ocean) does not persist the storage if the pod is deleted.
I have changed the reclaim policy of the storage from Delete to Retain but this does not make a difference.
This is a copy of DB YAML file:
apiVersion: v1
kind: Service
metadata:
name: db
namespace: hm-namespace01
app: app1
spec:
type: NodePort
ports:
- port: 5432
selector:
app: app1
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: hm-pv-claim
namespace: hm-namespace01
labels:
app: app1
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
storageClassName: do-block-storage
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: app1
namespace: hm-namespace01
labels:
app: app1
spec:
selector:
matchLabels:
app: app1
tier: backend
strategy:
type: Recreate
template:
metadata:
labels:
app: app1
tier: backend
spec:
containers:
- name: app1
image: postgres:11
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 5432
volumeMounts:
- name: postgredb
mountPath: /var/lib/postgresql
volumes:
- name: postgredb
persistentVolumeClaim:
claimName: hm-pv-claim
You must match your mountPath with the Postgres PGDATA environment variable.
The default value of PGDATA is /var/lib/postgresql/data (not /var/lib/postgresql).
You need to either adjust your mountPath or set the PGDATA env to match it.
Related
I have a Raspberry Pi Cluster consisting of 1-Master 20-Nodes:
192.168.0.92 (Master)
192.168.0.112 (Node w/ USB Drive)
I mounted a USB drive to /media/hdd & set a label - purpose=volume to it.
Using the following I was able to setup a NFS server:
apiVersion: v1
kind: Namespace
metadata:
name: storage
labels:
app: storage
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: local-pv
namespace: storage
spec:
capacity:
storage: 3.5Ti
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Retain
storageClassName: local-storage
local:
path: /media/hdd
nodeAffinity:
required:
nodeSelectorTerms:
- matchExpressions:
- key: purpose
operator: In
values:
- volume
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: local-claim
namespace: storage
spec:
accessModes:
- ReadWriteOnce
storageClassName: local-storage
resources:
requests:
storage: 3Ti
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nfs-server
namespace: storage
labels:
app: nfs-server
spec:
replicas: 1
selector:
matchLabels:
app: nfs-server
template:
metadata:
labels:
app: nfs-server
name: nfs-server
spec:
containers:
- name: nfs-server
image: itsthenetwork/nfs-server-alpine:11-arm
env:
- name: SHARED_DIRECTORY
value: /exports
ports:
- name: nfs
containerPort: 2049
- name: mountd
containerPort: 20048
- name: rpcbind
containerPort: 111
securityContext:
privileged: true
volumeMounts:
- mountPath: /exports
name: mypvc
volumes:
- name: mypvc
persistentVolumeClaim:
claimName: local-claim
nodeSelector:
purpose: volume
---
kind: Service
apiVersion: v1
metadata:
name: nfs-server
namespace: storage
spec:
ports:
- name: nfs
port: 2049
- name: mountd
port: 20048
- name: rpcbind
port: 111
clusterIP: 10.96.0.11
selector:
app: nfs-server
And I was even able to make a persistent volume with this:
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-nfs-volume
labels:
directory: mysql
spec:
capacity:
storage: 200Gi
volumeMode: Filesystem
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Retain
storageClassName: slow
nfs:
path: /mysql
server: 10.244.19.5
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mysql-nfs-claim
spec:
storageClassName: slow
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 100Gi
selector:
matchLabels:
directory: mysql
But when I try to use the volume like so:
apiVersion: v1
kind: Service
metadata:
name: wordpress-mysql
labels:
app: wordpress
spec:
ports:
- port: 3306
selector:
app: wordpress
tier: mysql
clusterIP: None
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: wordpress-mysql
labels:
app: wordpress
spec:
selector:
matchLabels:
app: wordpress
tier: mysql
strategy:
type: Recreate
template:
metadata:
labels:
app: wordpress
tier: mysql
spec:
containers:
- image: mysql:5.6
name: mysql
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-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-nfs-claim
I get NFS version transport protocol not supported error.
When seeing mount.nfs: requested NFS version or transport protocol is not supported error there are three main reasons:
NFS services are not running on NFS server
NFS utils not installed on the client
NFS service hung on NFS server
According tho this artice there are three solutions to resolve the problem with your error.
First one:
Login to the NFS server and check the NFS services status. If the following command
service nfs status returns an information that NFS services are stopped on the server - just start them using service nfs start. To mount NFS share on the client use the same command.
Second one:
If after trying first solution your problem isn't resolved
try installing package nfs-utils on your server.
Third one:
Open file /etc/sysconfig/nfs and try to check below parameters
# Turn off v4 protocol support
#RPCNFSDARGS="-N 4"
# Turn off v2 and v3 protocol support
#RPCNFSDARGS="-N 2 -N 3"
Removing hash from RPCNFSDARGS lines will turn off specific version support. This way clients with mentioned NFS versions won’t be able to connect to the NFS server for mounting share. If you have any of it enabled, try disabling it and mounting at the client after the NFS server service restarts.
I read the following kubernetes docs which resulted in the following yaml's to run postgresql & pgadmin in a cluster:
--- pgadmin-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: pgadmin-deployment
spec:
replicas: 1
selector:
matchLabels:
app: pgadmin-pod
template:
metadata:
labels:
app: pgadmin-pod
spec:
containers:
- name: pgadmin-container
image: dpage/pgadmin4
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 80
env:
- name: PGADMIN_DEFAULT_EMAIL
value: email#example.com
- name: PGADMIN_DEFAULT_PASSWORD
value: password
--- pgadmin-service.yaml
apiVersion: v1
kind: Service
metadata:
name: pgadmin-service
spec:
type: NodePort
ports:
- port: 30000
targetPort: 80
selector:
app: pgadmin-pod
--- postgres-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgres-deployment
spec:
replicas: 1
selector:
matchLabels:
app: postgres-pod
template:
metadata:
labels:
app: postgres-pod
spec:
containers:
- name: postgres-container
image: postgres:9.6-alpine
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 5432
env:
- name: POSTGRES_DB
value: database
- name: POSTGRES_PASSWORD
value: password
- name: POSTGRES_USER
value: username
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgrepvc
volumes:
- name: postgrepvc
persistentVolumeClaim:
claimName: postgres-pv-claim
--- postgres-service.yaml
apiVersion: v1
kind: Service
metadata:
name: postgres-service
spec:
type: NodePort
ports:
- port: 30001
targetPort: 5432
selector:
app: postgres-pod
--- postgres-storage.yaml
postgres-storage.yaml
kind: PersistentVolume
apiVersion: v1
metadata:
name: postgres-pv-volume
labels:
type: local
app: postgres
spec:
storageClassName: manual
capacity:
storage: 5Gi
accessModes:
- ReadWriteMany
hostPath:
path: "/mnt/data"
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: postgres-pv-claim
labels:
app: postgres
spec:
storageClassName: manual
accessModes:
- ReadWriteMany
resources:
requests:
storage: 5Gi
I then run the following command kubectl create -f ./ which results in the following:
kubernetes pods / svc's
Then I try to access pgAdmin on 10.43.225.170:30000 from outside of the cluster, but I get "10.43.225.170 took too long to respond." no matter what I try.
So how do I expose pgAdmin & postgress to the outside world, and is there a way to give them static ip's so I don't have to update ip's in connection strings each time I re-deploy on kubernetes, or do I have to use statefulset for this?
Problems here
you are trying to reach node internal ip 10.43.225.170 instead of external one.
nodePort service configured incorrectly. In addition you are trying to call incorrect port
You haven't specified what platform you use. I'm using GKE, so in my case its easier because I have external IP's automatically assigned during cluster node creation. But I had to manually create ingress firewall rule to allow access from outside to nodes and required ports (30000,30001)
In any case, to be able to use nodePort - you should have external IP address assigned to one of the nodes in cluster and a Firewall rule that allows ingress traffic to that port
Going next. You are trying to call <NodeIP>:spec.ports[*].port.
As per Type NodePort documentation:
Service is visible as <NodeIP>:spec.ports[*].nodePort
You need explicitly specify nodePort
I have changed a bit your deployment, can access pgAdmin after deploying it and opening corresponding ports in firewall.
apiVersion: apps/v1
kind: Deployment
metadata:
name: pgadmin-deployment
spec:
replicas: 1
selector:
matchLabels:
app: pgadmin-pod
template:
metadata:
labels:
app: pgadmin-pod
spec:
containers:
- name: pgadmin-container
image: dpage/pgadmin4
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 80
env:
- name: PGADMIN_DEFAULT_EMAIL
value: email#example.com
- name: PGADMIN_DEFAULT_PASSWORD
value: password
---
apiVersion: v1
kind: Service
metadata:
name: pgadmin-service
spec:
type: NodePort
ports:
- nodePort: 30000
targetPort: 80
port: 80
selector:
app: pgadmin-pod
--- postgres-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgres-deployment
spec:
replicas: 1
selector:
matchLabels:
app: postgres-pod
template:
metadata:
labels:
app: postgres-pod
spec:
containers:
- name: postgres-container
image: postgres:9.6-alpine
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 5432
env:
- name: POSTGRES_DB
value: database
- name: POSTGRES_PASSWORD
value: password
- name: POSTGRES_USER
value: username
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgrepvc
volumes:
- name: postgrepvc
persistentVolumeClaim:
claimName: postgres-pv-claim
---
apiVersion: v1
kind: Service
metadata:
name: postgres-service
spec:
type: NodePort
ports:
- nodePort: 30001
targetPort: 5432
port: 5432
selector:
app: postgres-pod
---
kind: PersistentVolume
apiVersion: v1
metadata:
name: postgres-pv-volume
labels:
type: local
app: postgres
spec:
storageClassName: manual
capacity:
storage: 5Gi
accessModes:
- ReadWriteMany
hostPath:
path: "/mnt/data"
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: postgres-pv-claim
labels:
app: postgres
spec:
storageClassName: manual
accessModes:
- ReadWriteMany
resources:
requests:
storage: 5Gi
Check:
kubectl apply -f pg_my.yaml
deployment.apps/pgadmin-deployment created
service/pgadmin-service created
service/postgres-service created
persistentvolume/postgres-pv-volume created
persistentvolumeclaim/postgres-pv-claim created
#In my case I take node external ip from any node from `kubectl get nodes -o wide` output:
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP
gke-cluster-1-default-pool-*******-***** Ready <none> 20d v1.18.16-gke.502 10.186.0.7 *.*.*.*
curl *.*.*.*:30000
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>Redirecting...</title>
<h1>Redirecting...</h1>
<p>You should be redirected automatically to target URL: /login?next=%2F.
Trying to deploy a stateful jupyter notebook in Kubernetes, but not able to save the code written in a notebook, whenever the notebook pod is going down all the code is being deleted. I tried to use persistent volume but unable to achieve the expected result.
UPDATE
Changed mount path to "/home/jovyan" as jyputer saves the ipynb in this location. But now getting PermissionError: [Errno 13] Permission denied: '/home/jovyan/.local' while deploying the pod.
kind: Ingress
metadata:
name: jupyter-ingress
spec:
backend:
serviceName: jupyter-notebook-service
servicePort: 8888
---
kind: Service
apiVersion: v1
metadata:
name: jupyter-notebook-service
spec:
clusterIP: None
selector:
app: jupyter-notebook
ports:
- protocol: TCP
port: 8888
targetPort: 8888
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: jupyter-notebook
labels:
app: jupyter-notebook
spec:
replicas: 1
serviceName: "jupyter-notebook-service"
selector:
matchLabels:
app: jupyter-notebook
template:
metadata:
labels:
app: jupyter-notebook
spec:
serviceAccountName: dsx-spark
volumes:
- name: jupyter-pv-storage
persistentVolumeClaim:
claimName: jupyter-pv-claim
containers:
- name: minimal-notebook
image: jupyter/pyspark-notebook:latest
ports:
- containerPort: 8888
command: ["start-notebook.sh"]
args: ["--NotebookApp.token=''"]
volumeMounts:
- mountPath: "/home/jovyan"
name: jupyter-pv-storage
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: jupyter-pv-claim
spec:
storageClassName: jupyter-pv-storage
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
---
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: jupyter-pv-volume
labels:
type: local
spec:
storageClassName: jupyter-pv-storage
capacity:
storage: 1Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/home/jovyan"
---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: jupyternotebook-pv-storage
annotations:
storageclass.kubernetes.io/is-default-class: "true"
labels:
provisioner: kubernetes.io/vsphere-volume
parameters:
diskformat: zeroedthick
```
The Pod with jupyter notebook is non-root user so unable to mount the so we are
using initContainers to change user/permission of the Persistent Volume Claim before creating the Pod.
kind: StatefulSet
metadata:
name: jupyter-notebook
labels:
app: jupyter-notebook
spec:
replicas: 1
serviceName: "jupyter-notebook-service"
selector:
matchLabels:
app: jupyter-notebook
template:
metadata:
labels:
app: jupyter-notebook
spec:
serviceAccountName: dsx-spark
volumes:
- name: ci-jupyter-storage-def
persistentVolumeClaim:
claimName: my-jupyter-pv-claim
containers:
- name: minimal-notebook
image: jupyter/pyspark-notebook:latest
ports:
- containerPort: 8888
command: ["start-notebook.sh"]
args: ["--NotebookApp.token=''"]
volumeMounts:
- mountPath: "/home/jovyan/work"
name: ci-jupyter-storage-def
initContainers:
- name: jupyter-data-permission-fix
image: busybox
command: ["/bin/chmod","-R","777", "/data"]
volumeMounts:
- name: ci-jupyter-storage-def
mountPath: /data```
As I have already mentioned in the comments you need to make sure that:
The storage for a given Pod must either be provisioned by a PersistentVolume Provisioner based on the requested storage class, or pre-provisioned by an admin. The volumeClaimTemplates will provide stable storage using PersistentVolumes. PersistentVolumes associated with the Pods’ PersistentVolume Claims are not deleted when the Pods, or StatefulSet are deleted.
The container is running as a user that has the permissions to access that volume. It can be done by changing the permissions to 777 or as you already noticed by using a proper initContainers.
I am running local k8s cluster and defining PV as hostPath for mysql pods.
Sharing all the configuration details below .
kind: PersistentVolume
apiVersion: v1
metadata:
name: mysql-pv-volume
labels:
type: local
spec:
storageClassName: manual
capacity:
storage: 2Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/mnt/data"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mysql-pv-claim
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 2Gi
---
apiVersion: v1
kind: Service
metadata:
name: mysql
spec:
ports:
- port: 3306
selector:
app: mysql
clusterIP: None
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
name: mysql
spec:
selector:
matchLabels:
app: mysql
strategy:
type: Recreate
template:
metadata:
labels:
app: mysql
spec:
containers:
- image: mysql:5.7
name: mysql
env:
# Use secret in real usage
- name: MYSQL_ROOT_PASSWORD
value: password
ports:
- containerPort: 3306
name: mysql
volumeMounts:
- name: mysql-persistent-storage
mountPath: /var/lib/mysql
volumes:
- name: mysql-persistent-storage
persistentVolumeClaim:
claimName: mysql-pv-claim
The problem I am getting is as mysql pod is running in k8s cluster ,when its deleted and recreate ,it will choose any one of the node and deployed .So mysql hostpath always mounted to specific node .Is it a good idea to fix the node for mysql or any other options are there ?please share if any idea .
you have below choices
Use node selector or node affinity to ensure that pod gets scheduled on the node where the mount is created OR
Use local persistent volumes. it is supported on kubernetes 1.14 and above
Why are you using a PVC and a PV? Actually, for hostPath, you don't even need to create the PV object. It just gets it.
You should use a StatefulSet if you want a pod that is re-created to get the storage it was using the previous one (state).
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: web
spec:
selector:
matchLabels:
app: mysql
serviceName: "mysql"
replicas: 1
template:
metadata:
labels:
app: mysql
spec:
terminationGracePeriodSeconds: 10
containers:
- name: mysql
image: mysql:5.7
env:
- name: MYSQL_ROOT_PASSWORD
value: password
ports:
- containerPort: 3306
name: mysql
volumeMounts:
- name: mysql-persistent-storage
mountPath: /var/lib/mysql
volumeClaimTemplates:
- metadata:
name: mysql-persistent-storage
spec:
accessModes: ["ReadWriteOnce"]
# storageClassName: "standard"
resources:
requests:
storage: 2Gi
This statefulSet fails, but it is a mysql thing. As reference, should serve.
I want to create common persistence volume with nfs.
PV(nfs):
common-data-pv 1500Gi RWO Retain
192.168.0.24 /home/common-data-pv
I want a claim or pod(mount the claim) subscribed common-data-pv can define path example :
/home/common-data-pv/www-site-1(50GI)
/home/common-data-pv/www-site-2(50GI)
But i not found in documentation how i can define this.
My actual conf for pv :
kind: PersistentVolume
apiVersion: v1
metadata:
name: common-data-pv
labels:
type: common
spec:
capacity:
storage: 1500Gi
accessModes:
- ReadWriteMany
nfs:
server: 192.168.122.1
path: "/home/pv/common-data-pv"
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: common-data-pvc
namespace: kube-system
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 10Gi
selector:
matchLabels:
type: common
Example use:
apiVersion: v1
kind: ReplicationController
metadata:
name: nfs-web-1
namespace: kube-system
spec:
replicas: 2
selector:
role: web-frontend
template:
metadata:
labels:
role: web-frontend
spec:
containers:
- name: web
image: nginx:alpine
ports:
- name: web
containerPort: 80
volumeMounts:
# name must match the volume name below
- name: nfs
mountPath: "/usr/share/nginx/html"
volumes:
- name: nfs
persistentVolumeClaim:
claimName: common-data-pvc
apiVersion: v1
kind: ReplicationController
metadata:
name: nfs-web-2
namespace: kube-system
spec:
replicas: 2
selector:
role: web-frontend
template:
metadata:
labels:
role: web-frontend
spec:
containers:
- name: web
image: nginx:alpine
ports:
- name: web
containerPort: 80
volumeMounts:
# name must match the volume name below
- name: nfs
mountPath: "/usr/share/nginx/html"
volumes:
- name: nfs
persistentVolumeClaim:
claimName: common-data-pvc
To use the claim you just need to add a volumeMounts section and volumes to your manifest. Here's an example replication controller for nginx that would use your claim. Note the very last line that uses the same PVC name.
apiVersion: v1
kind: ReplicationController
metadata:
name: nfs-web
namespace: kube-system
spec:
replicas: 2
selector:
role: web-frontend
template:
metadata:
labels:
role: web-frontend
spec:
containers:
- name: web
image: nginx:alpine
ports:
- name: web
containerPort: 80
volumeMounts:
# name must match the volume name below
- name: nfs
mountPath: "/usr/share/nginx/html"
volumes:
- name: nfs
persistentVolumeClaim:
claimName: common-data-pvc
More examples can be found in the kubernetes repo under examples