On Premises Kubernetes Deployment
OpenMetadata supports the Installation and Running of application on OnPremises Kubernetes through Helm Charts. However, there are some additional configurations which needs to be done as prerequisites for the same.
Note
This guide presumes you have an on premises Kubernetes cluster setup and you are installing OpenMetadata in default namespace.
Prerequisites
Persistent Volumes with ReadWriteMany Access Modes
OpenMetadata helm chart depends on Airflow and Airflow expects a presistent disk that support ReadWriteMany (the volume can be mounted as read-write by many nodes).
The workaround is to create nfs-share and use that as the presistent claim to delpoy OpenMetadata by implementing the following steps in order.
Note
This guide assumes you have NFS Server already setup with Hostname or IP Address which is reachable from your on premises Kubernetes cluster and you have configured a path to be used for OpenMetadata Airflow Helm Dependency.
Dynamic Provisioning using StorageClass
To provision PersistentVolume dynamically using the StorageClass, you need to install the NFS provisioner. It is recommended to use nfs-subdir-external-provisioner helm charts for this case.
helm repo add nfs-subdir-external-provisioner https://kubernetes-sigs.github.io/nfs-subdir-external-provisioner
helm install nfs-subdir-external-provisioner nfs-subdir-external-provisioner/nfs-subdir-external-provisioner \
--create-namespace \
--namespace nfs-provisioner \
--set nfs.server=<NFS_HOSTNAME_OR_IP> \
--set nfs.path=/airflow
Replace the `NFS_HOSTNAME_OR_IP` with your NFS Server value and run the commands.
This will create a new StorageClass with `nfs-subdir-external-provisioner`. You can view the same using the kubectl command `kubectl get storageclass -n nfs-provisioner`.
Provision NFS backed PVC for Airflow DAGs and Airflow Logs
Change owner and permission manually on disks
Since airflow pods run as non root users, they would not have write access on the nfs server volumes. In order to fix the permission here, spin up a pod with persistent volumes attached and run it once.
# permissions_pod.yml
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: my-permission-pod
name: my-permission-pod
spec:
containers:
- image: busybox
name: my-permission-pod
volumeMounts:
- name: airflow-dags
mountPath: /airflow-dags
- name: airflow-logs
mountPath: /airflow-logs
command:
- "chown -R 50000 /airflow-dags /airflow-logs"
# if needed
- "chmod -R a+rwx /airflow-dags"
volumes:
- name: airflow-logs
persistentVolumeClaim:
claimName: openmetadata-dependencies-logs
- name: airflow-dags
persistentVolumeClaim:
claimName: openmetadata-dependencies-dags
dnsPolicy: ClusterFirst
restartPolicy: Always
Note
Airflow runs the pods with linux user name as airflow and linux user id as 50000.
Run the below command to create the pod and fix the permissions
kubectl create -f permissions_pod.yml
Create OpenMetadata dependencies Values
Override openmetadata dependencies airflow helm values to bind the nfs persistent volumes for DAGs and logs.
# values-dependencies.yml
airflow:
airflow:
extraVolumeMounts:
- mountPath: /airflow-logs
name: nfs-airflow-logs
- mountPath: /airflow-dags/dags
name: nfs-airflow-dags
extraVolumes:
- name: nfs-airflow-logs
persistentVolumeClaim:
claimName: openmetadata-dependencies-logs
- name: nfs-airflow-dags
persistentVolumeClaim:
claimName: openmetadata-dependencies-dags
config:
AIRFLOW__OPENMETADATA_AIRFLOW_APIS__DAG_GENERATED_CONFIGS: "/airflow-dags/dags"
dags:
path: /airflow-dags/dags
persistence:
enabled: false
logs:
path: /airflow-logs
persistence:
enabled: false
For more information on airflow helm chart values, please refer to airflow-helm.
Follow OpenMetadata Kubernetes Deployment to install and deploy helm charts with nfs volumes. When deploying openmetadata dependencies helm chart, use the below command -
helm install openmetadata-dependencies open-metadata/openmetadata-dependencies --values values-dependencies.yaml