Using iSCSI storage for container apps on ROSA

• How to deploy a Postgresql application using iSCSI storage class

• Red Hat account
• Access to Red Hat OpenShift on the Red Hat Hybrid Cloud Console
• Amazon Web Services account
• IAM user credential with appropriate permissions to create and access ROSA cluster
• AWS command line-interface
• ROSA command line-interface
• OpenShift command-line interface (oc)
• Helm 3 documentation
• A HCP ROSA cluster

Use the following yaml to deploy the postgreSQL app. 

1. Inspect the setup file using the command #cat postgres-san.yaml 

   a. Review the PostgreSQL database application:

   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:14
           env:
           - name: POSTGRES_USER
             #value: "myuser"
             value: "admin"
           - name: POSTGRES_PASSWORD
             #value: "mypassword"
             value: "adminpass"
           - name: POSTGRES_DB
             value: "mydb"
           - name: PGDATA
             value: "/var/lib/postgresql/data/pgdata"
           ports:
           - containerPort: 5432
           volumeMounts:
           - name: postgres-storage
             mountPath: /var/lib/postgresql/data
         volumes:
         - name: postgres-storage
           persistentVolumeClaim:
             claimName: postgres-pvc

   b. Request dedicated digital storage “sc-fsx-san”

    ---
   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: postgres-pvc
   spec:
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 5Gi
     storageClassName: sc-fsx-san

   c. Create a stable network address to connect to your database 

   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: postgres
   spec:
     selector:
       app: postgres
     ports:
     - protocol: TCP
       port: 5432
       targetPort: 5432
     type: ClusterIP
   

   d. Create a dedicated space and run the setup commands

   #oc create namespace postgres-san
   root@localhost HAFSX]# oc create -f postgres-san.yaml -n postgres-san
   deployment.apps/postgres created
   persistentvolumeclaim/postgres-pvc created
   service/postgres created

2. Verify that the application pod is running and that a PVC and PV are created for the application. 

    

   a. Note:  the storage class for the PVC uses the san storage class previously created using iSCSI.

3. Verify that iSCSi sessions are created in the node where the pod runs.
   
   
   
    
4. Verify that a lun is created on the volume in FSxN  for this application and the lun is mapped. You can log into the FSxN CLI using fsxadmin and the password you previously created.
   
   
   

You have now successfully deployed a Postgresql application using iSCSI storage class!

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