Adds ProviderTransformer to msgraph catalog plugin for dynamic config

Signed-off-by: Adam Wallis <adam.wallis@gmail.com>

docs/integrations/azure/org.md

@@ -169,6 +169,23 @@ microsoftGraphOrg:
       select: ['id', 'displayName', 'description']
 ```
 
+### Using Provider Config Transformer
+
+Dynamic configuration scaling allows the `msgraph` catalog plugin to adjust its settings at runtime without requiring a redeploy. This feature is useful for scenarios where configuration needs to be updated based on real-time events or changing conditions. For example, you can dynamically adjust synchronization schedules, filters, and search parameters to optimize performance and responsiveness.
+
+:::note
+Adjusting fields that are not used on each scheduled ingestion (e.g., `id`, `schedule`) will have no effect.
+:::
+
+:::warning
+Dynamically changing configuration on the fly can introduce unintended consequences, such as system instability and configuration errors. Please review your transformer carefully to ensure that it is working as anticipated!
+:::
+
+#### Example Use Cases:
+
+- **Filter Scaling**: Adjust filters like `userGroupMember` and `groupFilter` dynamically.
+- **Search Parameter Adjustment**: Change search parameters such as `groupSearch` and `userSelect` on-the-fly.
+
 ### Using Custom Transformers
 
 Transformers can be configured by extending `microsoftGraphOrgEntityProviderTransformExtensionPoint`. Here is an example:
@@ -180,6 +197,7 @@ import {
   myUserTransformer,
   myGroupTransformer,
   myOrganizationTransformer,
+  myProviderConfigTransformer,
 } from './transformers';
 
 backend.add(
@@ -201,6 +219,9 @@ backend.add(
           microsoftGraphTransformers.setOrganizationTransformer(
             myOrganizationTransformer,
           );
+          microsoftGraphTransformers.setProviderConfigTransformer(
+            myProviderConfigTransformer,
+          );
           /* highlight-add-end */
         },
       });
@@ -209,7 +230,7 @@ backend.add(
 );
 ```
 
-The `myUserTransformer`, `myGroupTransformer`, and `myOrganizationTransformer` transformer functions are from the examples in the section below.
+The `myUserTransformer`, `myGroupTransformer`, `myOrganizationTransformer`, and `myProviderConfigTransformer` transformer functions are from the examples in the section below.
 
 ### Transformer Examples
 
@@ -221,6 +242,7 @@ import {
   defaultGroupTransformer,
   defaultUserTransformer,
   defaultOrganizationTransformer,
+  MicrosoftGraphProviderConfig,
 } from '@backstage/plugin-catalog-backend-module-msgraph';
 import { GroupEntity, UserEntity } from '@backstage/catalog-model';
 
@@ -263,6 +285,16 @@ export async function myOrganizationTransformer(
 ): Promise<GroupEntity | undefined> {
   return undefined;
 }
+
+// Example config transformer that expands the group filter to also include 'azure-group-a'
+export async function myProviderConfigTransformer(
+  provider: MicrosoftGraphProviderConfig,
+): Promise<MicrosoftGraphProviderConfig> {
+  if (!provider.groupFilter?.includes('azure-group-a')) {
+    provider.groupFilter = `${provider.groupFilter} or displayName eq 'azure-group-a'`;
+  }
+  return provider;
+}
 ```
 
 ## Troubleshooting