docs: (IAC-1208) Crunchy 4 PostgreSQL Transfer Tooling Experimental Doc

docs/user/PostPostgreSQLDataTransfer_Experimental.md

@@ -17,6 +17,8 @@ You had an existing SAS Viya platform deployment that was created using the viya
 
 ### Recommended Steps:
 
+#### Crunchy 5
+
 1. After following the [PostgreSQL Data Transfer Guide](https://documentation.sas.com/?cdcId=itopscdc&cdcVersion=default&docsetId=pgdatamig&docsetTarget=titlepage.htm) under "Steps for Crunchy Data 5" you manually added entries for the external PostgreSQL clusters into the kustomization.yaml and produced a file that includes details for **both** the internal Crunchy and external Postgres instance. You then built and applied the manifest so that the Viya deployment is reconfigured to point to the external Postgres instance.
 2. The final step in the [PostgreSQL Data Transfer Guide](https://documentation.sas.com/?cdcId=itopscdc&cdcVersion=default&docsetId=pgdatamig&docsetTarget=titlepage.htm) under "Steps for Crunchy Data 5"  asks you to manually remove entries to related to Crunchy and rebuild your manifests again. At this point in time you could instead remove the manual modifications you made to the kustomization.yaml and make changes to your `ansible-vars.yaml` so that the viya4-deployment project can manage your installation again.
    1. First remove any files you manually copied over to site-config to configure the external PostgreSQL clusters. Like `sas-bases/examples/postgres/postgres-user.env` and `site-config/postgres/dataserver-transformer.yaml`, viya4-deployment will be generating this for you.
@@ -30,4 +32,20 @@ You had an existing SAS Viya platform deployment that was created using the viya
       * If as part of your data transfer, you provisioned your PostgreSQL clusters without the use of a Viya 4 IAC projects, then you will need to manually add definitions for each of your PostgreSQL clusters. You can see an example definition here in our [CONFIG-VARS.md documentation](https://github.com/sassoftware/viya4-deployment/blob/main/docs/CONFIG-VARS.md#postgresql)
    2. If your PostgreSQL Cluster requires a certificate for connection, in your `ansible-vars.yaml` ensure that `V4_CFG_TLS_TRUSTED_CA_CERTS` is set and points to either the certificate or a directory containing that certificate.
    3. In your `ansible-vars.yaml` set `DEPLOY` to false
-   4. Run the ansible-playbook again with the `viya,install` tags. Since `DEPLOY` is set to false, the SAS Viya platform deployment will not be modified, however in your deployment directory you should see an updated kustomization.yaml with generated entries for your PostgreSQL clusters and those files should automatically be present in your site-config directory.
+   4. Run the ansible-playbook again with the `viya,install` tags. Since `DEPLOY` is set to false, the SAS Viya platform deployment will not be modified, however in your deployment directory you should see an updated kustomization.yaml with generated entries for your PostgreSQL clusters and those files should automatically be present in your site-config directory.
+
+#### Crunchy 4 
+
+1. While following the [PostgreSQL Data Transfer Guide](https://documentation.sas.com/?cdcId=itopscdc&cdcVersion=default&docsetId=pgdatamig&docsetTarget=titlepage.htm) under "Steps for Crunchy Data 4" in Step 5 you are asked to remove all entries in your kustomization.yaml that contain a set of strings that are used for Crunchy 4 Data PostgreSQL configuration. Since the viya4-deployment project automatically manages the configuration and creation of the PostgreSQL related entries in your kustomziation.yaml, you can skip Step 5 from the "Steps for Crunchy Data 4" for now.
+2. You will now need to configure your ansible-vars.yaml to make the switch over from Crunchy Data PostgreSQL to an external PostgreSQL cluster.
+      * If as part of your data transfer, you provisioned your PostgreSQL clusters using any [Viya 4 IAC projects](https://github.com/search?q=org%3Asassoftware+viya4-iac-&type=repositories), then your PostgreSQL configuration and connection information should already be present in the .tfstate file, so you don't need to add those entries in your `ansible-vars.yaml`. You should modify the `V4_CFG_POSTGRES_SERVERS` variable if it's still configured to use an internal Crunchy instance like so:
+      ```yaml
+      # modify as below to use external instance
+      V4_CFG_POSTGRES_SERVERS:
+        default:
+          internal: false
+      ```
+      * If as part of your data transfer, you provisioned your PostgreSQL clusters without the use of a Viya 4 IAC project, then you will need to manually add definitions for each of your PostgreSQL clusters. You can see an example definition here in our [CONFIG-VARS.md documentation](https://github.com/sassoftware/viya4-deployment/blob/main/docs/CONFIG-VARS.md#postgresql)
+3. Going back to the [PostgreSQL Data Transfer Guide](https://documentation.sas.com/?cdcId=itopscdc&cdcVersion=default&docsetId=pgdatamig&docsetTarget=titlepage.htm) under "Steps for Crunchy Data 4" perform Step 8 and start the operator if your deployment is managed by the SAS Deployment Operator (if `V4_DEPLOYMENT_OPERATOR_ENABLED` was set to true)
+4. Run the ansible-playbook again with the `viya,install` tags. This will update the kustomization.yaml by removing entries related to Crunchy 4 and add entries for your external PostgreSQL cluster, all managed by viya4-deployment. The manifest will be rebuilt and reapplied to the cluster.
+5. Go back to the [PostgreSQL Data Transfer Guide](https://documentation.sas.com/?cdcId=itopscdc&cdcVersion=default&docsetId=pgdatamig&docsetTarget=titlepage.htm) under "Steps for Crunchy Data 4" and perform Steps 10 and onwards to complete the data transfer.