fix: embedding job fails using IAM role (#5252)

api/core/model_runtime/model_providers/bedrock/bedrock.yaml

@@ -23,7 +23,7 @@ provider_credential_schema:
     - variable: aws_access_key_id
       required: false
       label:
-        en_US: Access Key (If not provided, credentials are obtained from your running environment. e.g. IAM role)
+        en_US: Access Key (If not provided, credentials are obtained from the running environment.)
         zh_Hans: Access Key
       type: secret-input
       placeholder:

api/core/model_runtime/model_providers/bedrock/text_embedding/text_embedding.py

@@ -49,8 +49,8 @@ class BedrockTextEmbeddingModel(TextEmbeddingModel):
         bedrock_runtime = boto3.client(
             service_name='bedrock-runtime',
             config=client_config,
-            aws_access_key_id=credentials["aws_access_key_id"],
-            aws_secret_access_key=credentials["aws_secret_access_key"]
+            aws_access_key_id=credentials.get("aws_access_key_id", None),
+            aws_secret_access_key=credentials.get("aws_secret_access_key", None)
         )
 
         embeddings = []