From 2f342dc12d709666ca78f9d989313715d66ec216 Mon Sep 17 00:00:00 2001 From: CrypticDriver <107245892+CrypticDriver@users.noreply.github.com> Date: Wed, 22 Jul 2026 07:27:10 +0000 Subject: [PATCH] fix: honor AWS shared-config region for custom gateway hostnames MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The previous check only consulted AWS_REGION* env vars before rejecting custom hostnames, breaking deployments that configure their region via the AWS shared config (profile). Resolve through boto3's session (env vars + shared config) and only error when that chain yields nothing — never sign with a silently guessed region. --- litellm/llms/bedrock/search/transformation.py | 31 +++++++++++------ tests/search_tests/test_agentcore_search.py | 34 +++++++++++++++---- 2 files changed, 47 insertions(+), 18 deletions(-) diff --git a/litellm/llms/bedrock/search/transformation.py b/litellm/llms/bedrock/search/transformation.py index 3bae84f0026..9ab651f952c 100644 --- a/litellm/llms/bedrock/search/transformation.py +++ b/litellm/llms/bedrock/search/transformation.py @@ -190,11 +190,11 @@ class AgentCoreSearchConfig(BaseSearchConfig, BaseAWSLLM): # The signing region must match the gateway's region — derive it from # standard gateway hostnames so callers don't have to set - # aws_region_name to a region different from their default. Custom or - # private hostnames can't be parsed: fall back to an explicitly - # configured region (param or AWS env vars), and error out rather than - # silently signing for a guessed region the gateway would reject with - # a confusing auth error. + # aws_region_name to a region different from their default. For custom + # or private hostnames, defer to BaseAWSLLM's normal region resolution + # (params, env vars, AWS shared config / profile); only error out when + # that chain yields nothing, rather than silently signing for a guessed + # region the gateway would reject with a confusing auth error. signing_params = dict(optional_params) if signing_params.get("aws_region_name") is None: match = re.search( @@ -203,12 +203,21 @@ class AgentCoreSearchConfig(BaseSearchConfig, BaseAWSLLM): ) if match: signing_params["aws_region_name"] = match.group(1) - elif not any(get_secret_str(var) for var in ("AWS_REGION", "AWS_REGION_NAME", "AWS_DEFAULT_REGION")): - raise ValueError( - f"Cannot derive the SigV4 signing region from api_base '{api_base}'. " - "Set aws_region_name (or the AWS_REGION env var) to the gateway's " - "region when using a custom hostname." - ) + else: + # boto3's session resolution covers env vars AND the AWS shared + # config (profile region) — unlike BaseAWSLLM's helper, which + # silently defaults to us-west-2 when nothing is configured. + import boto3 + + configured_region = boto3.Session().region_name + if configured_region: + signing_params["aws_region_name"] = configured_region + else: + raise ValueError( + f"Cannot derive the SigV4 signing region from api_base '{api_base}' " + "or the AWS configuration chain. Set aws_region_name (or AWS_REGION / " + "a profile region) to the gateway's region when using a custom hostname." + ) # api_key="" (not None, but falsy) disables BaseAWSLLM's fallback to the # AWS_BEARER_TOKEN_BEDROCK env var: that token is a Bedrock Runtime diff --git a/tests/search_tests/test_agentcore_search.py b/tests/search_tests/test_agentcore_search.py index d5f6ab3e82f..c041bfc8d50 100644 --- a/tests/search_tests/test_agentcore_search.py +++ b/tests/search_tests/test_agentcore_search.py @@ -264,10 +264,12 @@ class TestAgentCoreSearch: assert mock_base_sign.call_args.kwargs["api_key"] == "" def test_sign_request_custom_hostname_requires_region(self): - """Non-standard hostnames can't yield a signing region — require it explicitly.""" + """Custom hostname + empty AWS config chain → clear error, no guessed region.""" config = AgentCoreSearchConfig() - saved = {var: os.environ.pop(var, None) for var in ("AWS_REGION", "AWS_REGION_NAME", "AWS_DEFAULT_REGION")} - try: + + mock_session = MagicMock() + mock_session.region_name = None # nothing configured anywhere + with patch("boto3.Session", return_value=mock_session): with pytest.raises(ValueError, match="signing region"): config.sign_request( headers={}, @@ -275,10 +277,28 @@ class TestAgentCoreSearch: request_data={"jsonrpc": "2.0"}, api_base="https://gateway.internal.example.com/mcp", ) - finally: - for var, val in saved.items(): - if val is not None: - os.environ[var] = val + + def test_sign_request_custom_hostname_uses_shared_config_region(self): + """Custom hostname + region from AWS shared config (profile) must be honored.""" + config = AgentCoreSearchConfig() + + mock_session = MagicMock() + mock_session.region_name = "eu-west-1" # e.g. from ~/.aws/config profile + with ( + patch("boto3.Session", return_value=mock_session), + patch.object( + AgentCoreSearchConfig.__mro__[2], # BaseAWSLLM + "_sign_request", + return_value=({}, b"{}"), + ) as mock_base_sign, + ): + config.sign_request( + headers={}, + optional_params={}, + request_data={"jsonrpc": "2.0"}, + api_base="https://gateway.internal.example.com/mcp", + ) + assert mock_base_sign.call_args.kwargs["optional_params"]["aws_region_name"] == "eu-west-1" def test_sign_request_passes_explicit_aws_credentials(self): """Explicit aws_* params (e.g. from a proxy search_tools entry) reach the signer."""