Eable entra ID authentication (#910)

Co-authored-by: Denis Oliana <denis.oliana@microsoft.com>

README.md

@@ -31,7 +31,7 @@ Please see the [section below](#add-an-identity-provider) for important informat
     These variables are required:
     - `AZURE_OPENAI_RESOURCE`
     - `AZURE_OPENAI_MODEL`
-    - `AZURE_OPENAI_KEY`
+    - `AZURE_OPENAI_KEY` (optional if using Entra ID)
 
     These variables are optional:
     - `AZURE_OPENAI_TEMPERATURE`
@@ -58,7 +58,7 @@ NOTE: You may find you need to set: MacOS: `export NODE_OPTIONS="--max-old-space
     - `DATASOURCE_TYPE` (should be set to `AzureCognitiveSearch`)
     - `AZURE_SEARCH_SERVICE`
     - `AZURE_SEARCH_INDEX`
-    - `AZURE_SEARCH_KEY`
+    - `AZURE_SEARCH_KEY` (optional if using Entra ID)
 
     These variables are optional:
     - `AZURE_SEARCH_USE_SEMANTIC_SEARCH`
@@ -188,6 +188,20 @@ The Citation panel is defined at the end of `frontend/src/pages/chat/Chat.tsx`.
 
 ```
 
+### Using Entra ID
+
+The app uses Azure OpenAI on your data [(see documentation)](https://learn.microsoft.com/en-us/azure/ai-services/openai/references/on-your-data). To enable Entra ID for intra-service authentication
+
+1. Enable managed identity on Azure OpenAI
+2. Configure AI search to allow access from Azure OpenAI
+   1. Enable Role Based Access control on the used AI search instance [(see documentation)](https://learn.microsoft.com/en-us/azure/search/search-security-enable-roles)
+   2. Assign `Search Index Data Reader` and `Search Service Contributor` to the identity of the Azure OpenAI instance
+3. Do not configure `AZURE_SEARCH_KEY` and `AZURE_OPENAI_KEY` to use Entra ID authentication.
+4. Configure the webapp identity
+   1. Enable managed identity in the app service that hosts the webapp
+   2. Go to the Azure OpenAI instance and assign the role `Cognitive Services OpenAI User` to the identity of the webapp
+
+Note: RBAC assignments can take a few minutes before becoming effective.
 
 ### Best Practices
 We recommend keeping these best practices in mind:
@@ -207,7 +221,7 @@ Note: settings starting with `AZURE_SEARCH` are only needed when using Azure Ope
 | --- | --- | ------------- |
 |AZURE_SEARCH_SERVICE||The name of your Azure AI Search resource|
 |AZURE_SEARCH_INDEX||The name of your Azure AI Search Index|
-|AZURE_SEARCH_KEY||An **admin key** for your Azure AI Search resource|
+|AZURE_SEARCH_KEY||An **admin key** for your Azure AI Search resource.|
 |AZURE_SEARCH_USE_SEMANTIC_SEARCH|False|Whether or not to use semantic search|
 |AZURE_SEARCH_QUERY_TYPE|simple|Query type: simple, semantic, vector, vectorSimpleHybrid, or vectorSemanticHybrid. Takes precedence over AZURE_SEARCH_USE_SEMANTIC_SEARCH|
 |AZURE_SEARCH_SEMANTIC_SEARCH_CONFIG||The name of the semantic search configuration to use if using semantic search.|
@@ -220,11 +234,11 @@ Note: settings starting with `AZURE_SEARCH` are only needed when using Azure Ope
 |AZURE_SEARCH_VECTOR_COLUMNS||List of fields in your Azure AI Search index that contain vector embeddings of your documents to use when formulating a bot response. Represent these as a string joined with "|", e.g. `"product_description|product_manual"`|
 |AZURE_SEARCH_PERMITTED_GROUPS_COLUMN||Field from your Azure AI Search index that contains AAD group IDs that determine document-level access control.|
 |AZURE_SEARCH_STRICTNESS|3|Integer from 1 to 5 specifying the strictness for the model limiting responses to your data.|
-|AZURE_OPENAI_RESOURCE||the name of your Azure OpenAI resource|
+|AZURE_OPENAI_RESOURCE||the name of your Azure OpenAI resource (only one of AZURE_OPENAI_RESOURCE/AZURE_OPENAI_ENDPOINT is required)|
 |AZURE_OPENAI_MODEL||The name of your model deployment|
-|AZURE_OPENAI_ENDPOINT||The endpoint of your Azure OpenAI resource.|
+|AZURE_OPENAI_ENDPOINT||The endpoint of your Azure OpenAI resource (only one of AZURE_OPENAI_RESOURCE/AZURE_OPENAI_ENDPOINT is required)|
 |AZURE_OPENAI_MODEL_NAME|gpt-35-turbo-16k|The name of the model|
-|AZURE_OPENAI_KEY||One of the API keys of your Azure OpenAI resource|
+|AZURE_OPENAI_KEY||One of the API keys of your Azure OpenAI resource (optional if using Entra ID)|
 |AZURE_OPENAI_TEMPERATURE|0|What sampling temperature to use, between 0 and 2. Higher values like 0.8 will make the output more random, while lower values like 0.2 will make it more focused and deterministic. A value of 0 is recommended when using your data.|
 |AZURE_OPENAI_TOP_P|1.0|An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass. We recommend setting this to 1.0 when using your data.|
 |AZURE_OPENAI_MAX_TOKENS|1000|The maximum number of tokens allowed for the generated answer.|

app.py

@@ -126,7 +126,7 @@ def init_openai_client():
         aoai_api_key = app_settings.azure_openai.key
         ad_token_provider = None
         if not aoai_api_key:
-            logging.debug("No AZURE_OPENAI_KEY found, using Azure AD auth")
+            logging.debug("No AZURE_OPENAI_KEY found, using Azure Entra ID auth")
             ad_token_provider = get_bearer_token_provider(
                 DefaultAzureCredential(), "https://cognitiveservices.azure.com/.default"
             )