3.3. Migrating local databases to an external database server using the Operator

Procedure

1. Configure port forwarding for the local PostgreSQL database pod by running the following command on a terminal:

   oc port-forward -n <your-namespace> <pgsql-pod-name> <forward-to-port>:<forward-from-port>

   Where:

   • The <pgsql-pod-name> variable denotes the name of a PostgreSQL pod with the format backstage-psql-<deployment-name>-<_index>.
   • The <forward-to-port> variable denotes the port of your choice to forward PostgreSQL data to.

   • The <forward-from-port> variable denotes the local PostgreSQL instance port, such as 5432.

     Example: Configuring port forwarding

     oc port-forward -n developer-hub backstage-psql-developer-hub-0 15432:5432

2. Make a copy of the following db_copy.sh script and edit the details based on your configuration:

   #!/bin/bash
   
   to_host=<db-service-host> 

   1

   
   to_port=5432 

   2

   
   to_user=postgres 

   3

   
   
   from_host=127.0.0.1 

   4

   
   from_port=15432 

   5

   
   from_user=postgres 

   6

   
   
   allDB=("backstage_plugin_app" "backstage_plugin_auth" "backstage_plugin_catalog" "backstage_plugin_permission" "backstage_plugin_scaffolder" "backstage_plugin_search") 

   7

   
   
   for db in ${!allDB[@]};
   do
     db=${allDB[$db]}
     echo Copying database: $db
     PGPASSWORD=$TO_PSW psql -h $to_host -p $to_port -U $to_user -c "create database $db;"
     pg_dump -h $from_host -p $from_port -U $from_user -d $db | PGPASSWORD=$TO_PSW psql -h $to_host -p $to_port -U $to_user -d $db
   done

   1

   The destination host name, for example, <db-instance-name>.rds.amazonaws.com.

   2

   The destination port, such as 5432.

   3

   The destination server username, for example, postgres.

   4

   The source host name, such as 127.0.0.1.

   5

   The source port number, such as the <forward-to-port> variable.

   6

   The source server username, for example, postgres.

   7

   The name of databases to import in double quotes separated by spaces, for example, ("backstage_plugin_app" "backstage_plugin_auth" "backstage_plugin_catalog" "backstage_plugin_permission" "backstage_plugin_scaffolder" "backstage_plugin_search").

3. Create a destination database for copying the data:

   /bin/bash TO_PSW=<destination-db-password> /path/to/db_copy.sh 

   1

   1

   The <destination-db-password> variable denotes the password to connect to the destination database.

   注意

   You can stop port forwarding when the copying of the data is complete. For more information about handling large databases and using the compression tools, see the Handling Large Databases section on the PostgreSQL website.

4. Reconfigure your Backstage custom resource (CR). For more information, see Configuring an external PostgreSQL instance using the Operator.

5. Check that the following code is present at the end of your Backstage CR after reconfiguration:

   # ...
   spec:
     database:
       enableLocalDb: false
     application:
     # ...
       extraFiles:
         secrets:
           - name: my-rhdh-database-certificates-secrets
             key: postgres-crt.pem # key name as in my-rhdh-database-certificates-secrets Secret
       extraEnvs:
         secrets:
           - name: my-rhdh-database-secrets
   # ...

   注意

   Reconfiguring the Backstage CR deletes the corresponding StatefulSet and Pod objects, but does not delete the PersistenceVolumeClaim object. Use the following command to delete the local PersistenceVolumeClaim object:

   oc -n developer-hub delete pvc <local-psql-pvc-name>

   where, the <local-psql-pvc-name> variable is in the data-<psql-pod-name> format.

6. Apply the configuration changes.

Verification

1. Verify that your RHDH instance is running with the migrated data and does not contain the local PostgreSQL database by running the following command:

   oc get pods -n <your-namespace>

2. Check the output for the following details:

   • The backstage-developer-hub-xxx pod is in running state.

   • The backstage-psql-developer-hub-0 pod is not available.

     You can also verify these details using the Topology view in the OpenShift Container Platform web console.