fix(integ): remove module-level env var from MTRL tests (#5929)

The 4 MTRL test files added in #5919 set SAGEMAKER_REGION=us-west-2
at module level via os.environ.setdefault(). When pytest collects tests,
it imports all modules in the directory—including these files—even when
filtering by mark (e.g. -m "gpu_intensive and us_east_1"). This poisons
the SageMakerClient singleton's region for the entire process, causing
the Nova us-east-1 integ tests (SFT, RLVR, BenchmarkEvaluator) to fail
with "ModelPackageGroup does not exist" because API calls land in
us-west-2 instead of us-east-1.

Changes:
- Remove os.environ.setdefault() calls from module level in all 4 files
- Move _ACCOUNT_ID resolution from module-level boto3 calls into lazy
  fixtures/functions (avoids import-time side effects)
- Use boto3.Session().client() pattern instead of boto3.client() to
  follow SDK conventions (wrapper over boto, not direct boto usage)
- Align with existing test patterns (DPO, SFT, RLVR) that rely on
  conftest fixtures for session management

Affected files:
- test_mtrl_evaluator.py
- test_mtrl_evaluator_3p_agent.py
- test_mtrl_trainer_integration.py
- test_multi_turn_rl_trainer_integration.py

Author: lucasjia-aws

sagemaker-train/tests/integ/train/test_mtrl_evaluator.py

@@ -22,9 +22,6 @@
 import pytest
 import logging
 
-os.environ.setdefault("AWS_DEFAULT_REGION", "us-west-2")
-os.environ.setdefault("SAGEMAKER_REGION", "us-west-2")
-
 import boto3
 from sagemaker.core.helper.session_helper import Session
 from sagemaker.train.evaluate import MultiTurnRLEvaluator
@@ -36,22 +33,30 @@
 # Timeout for evaluation pipeline execution (4 hours)
 EVALUATION_TIMEOUT_SECONDS = 14400
 
-# Resolve current account ID for account-agnostic paths
 _REGION = "us-west-2"
-_ACCOUNT_ID = boto3.client("sts", region_name=_REGION).get_caller_identity()["Account"]
-
-# Test configuration — uses current account for all resource paths
-TEST_CONFIG = {
-    #"base_model": "huggingface-vlm-qwen3-6-27b",
-    "base_model": "openai-reasoning-gpt-oss-20b",
-    "agent_arn": f"arn:aws:bedrock-agentcore:{_REGION}:{_ACCOUNT_ID}:runtime/sagemaker_rft_prod_gsm8k_streaming-Yk6O377mUS",
-    "dataset": f"s3://sagemaker-rft-{_ACCOUNT_ID}/prompts/gsm8k_small/prompts.parquet",
-    "s3_output_path": f"s3://sagemaker-{_REGION}-{_ACCOUNT_ID}/model-evaluation/output-artifacts/",
-    "mlflow_resource_arn": f"arn:aws:sagemaker:{_REGION}:{_ACCOUNT_ID}:mlflow-app/app-TTAUWUNMUHH6",
-    "model_package_group": f"arn:aws:sagemaker:{_REGION}:{_ACCOUNT_ID}:model-package-group/openai-reasoning-gpt-oss-20b-mtrl-mpg",
-    "role": f"arn:aws:iam::{_ACCOUNT_ID}:role/Admin",
-    "region": _REGION,
-}
+
+
+def _get_test_config():
+    """Build test configuration lazily (only when tests actually run)."""
+    boto_session = boto3.Session(region_name=_REGION)
+    account_id = boto_session.client("sts").get_caller_identity()["Account"]
+    return {
+        "base_model": "openai-reasoning-gpt-oss-20b",
+        "agent_arn": f"arn:aws:bedrock-agentcore:{_REGION}:{account_id}:runtime/sagemaker_rft_prod_gsm8k_streaming-Yk6O377mUS",
+        "dataset": f"s3://sagemaker-rft-{account_id}/prompts/gsm8k_small/prompts.parquet",
+        "s3_output_path": f"s3://sagemaker-{_REGION}-{account_id}/model-evaluation/output-artifacts/",
+        "mlflow_resource_arn": f"arn:aws:sagemaker:{_REGION}:{account_id}:mlflow-app/app-TTAUWUNMUHH6",
+        "model_package_group": f"arn:aws:sagemaker:{_REGION}:{account_id}:model-package-group/openai-reasoning-gpt-oss-20b-mtrl-mpg",
+        "role": f"arn:aws:iam::{account_id}:role/Admin",
+        "region": _REGION,
+        "account_id": account_id,
+    }
+
+
+@pytest.fixture(scope="module")
+def test_config():
+    """Lazily resolve test configuration (avoids module-level API calls)."""
+    return _get_test_config()
 
 
 def _ensure_model_package_group_exists(sm_client, group_name):
@@ -84,35 +89,35 @@ def _ensure_model_package_exists(sm_client, group_name, base_model_name):
 
 
 @pytest.fixture(scope="module")
-def sagemaker_session():
+def sagemaker_session_mtrl():
     """Create a SageMaker session with explicit region for CI environments."""
-    boto_session = boto3.Session(region_name=TEST_CONFIG["region"])
+    boto_session = boto3.Session(region_name=_REGION)
     return Session(boto_session=boto_session)
 
 
 @pytest.fixture(scope="module")
-def mtrl_trainer(sagemaker_session):
+def mtrl_trainer(sagemaker_session_mtrl, test_config):
     """Create a lightweight MultiTurnRLTrainer-like object for evaluator tests.
 
     Instead of going through the full constructor (which validates remote
     resources), we build a minimal object with the attributes the evaluator
     needs. This makes the test account-agnostic — it creates the required
     resources (model package group + model package) on the fly.
     """
-    sm_client = sagemaker_session.boto_session.client("sagemaker")
+    sm_client = sagemaker_session_mtrl.boto_session.client("sagemaker")
     group_name = "mtrl-integ-test-evaluator"
     _ensure_model_package_group_exists(sm_client, group_name)
     model_package_arn = _ensure_model_package_exists(
-        sm_client, group_name, TEST_CONFIG["base_model"]
+        sm_client, group_name, test_config["base_model"]
     )
 
     trainer = object.__new__(MultiTurnRLTrainer)
-    trainer._model_name = TEST_CONFIG["base_model"]
-    trainer._model_arn = f"arn:aws:sagemaker:{_REGION}:aws:hub-content/SageMakerPublicHub/Model/{TEST_CONFIG['base_model']}/1.0.0"
-    trainer.agent_env = TEST_CONFIG["agent_arn"]
+    trainer._model_name = test_config["base_model"]
+    trainer._model_arn = f"arn:aws:sagemaker:{_REGION}:aws:hub-content/SageMakerPublicHub/Model/{test_config['base_model']}/1.0.0"
+    trainer.agent_env = test_config["agent_arn"]
     trainer.bedrock_agentcore_qualifier = "DEFAULT"
-    trainer.output_model_package_group = TEST_CONFIG["model_package_group"]
-    trainer.sagemaker_session = sagemaker_session
+    trainer.output_model_package_group = test_config["model_package_group"]
+    trainer.sagemaker_session = sagemaker_session_mtrl
 
     # Use the real model package ARN from the account
     class _FakeJob:
@@ -131,27 +136,27 @@ class _FakeJob:
 class TestMTRLEvaluatorJobConfigDocument:
     """Tests validating the JobConfigDocument field naming for GA API contract."""
 
-    def test_bedrock_agent_config_fields(self, mtrl_trainer):
+    def test_bedrock_agent_config_fields(self, mtrl_trainer, test_config):
         """Verify BedrockAgentCoreConfig uses AgentRuntimeArn and Qualifier."""
         evaluator = MultiTurnRLEvaluator(
             model=mtrl_trainer,
-            dataset=TEST_CONFIG["dataset"],
-            s3_output_path=f'{TEST_CONFIG["s3_output_path"]}integ-fields-bedrock/',
-            mlflow_resource_arn=TEST_CONFIG["mlflow_resource_arn"],
-            role=TEST_CONFIG["role"],
-            region=TEST_CONFIG["region"],
-            agent_config=TEST_CONFIG["agent_arn"],
+            dataset=test_config["dataset"],
+            s3_output_path=f'{test_config["s3_output_path"]}integ-fields-bedrock/',
+            mlflow_resource_arn=test_config["mlflow_resource_arn"],
+            role=test_config["role"],
+            region=test_config["region"],
+            agent_config=test_config["agent_arn"],
             agent_qualifier="PROD",
         )
 
         evaluator._resolve_trainer_defaults()
         evaluator._resolve_agent_arn()
 
         ctx = evaluator._build_template_context(
-            aws_context={"region": TEST_CONFIG["region"], "account_id": _ACCOUNT_ID,
-                         "role_arn": TEST_CONFIG["role"]},
+            aws_context={"region": test_config["region"], "account_id": test_config["account_id"],
+                         "role_arn": test_config["role"]},
             artifacts={},
-            model_package_group_arn=TEST_CONFIG["model_package_group"],
+            model_package_group_arn=test_config["model_package_group"],
         )
 
         doc = json.loads(ctx["job_config_document_ft_str"])
@@ -166,27 +171,27 @@ def test_bedrock_agent_config_fields(self, mtrl_trainer):
         assert "AgentArn" not in agent_cfg.get("BedrockAgentCoreConfig", {})
         assert "BedrockAgentCoreQualifier" not in agent_cfg.get("BedrockAgentCoreConfig", {})
 
-    def test_lambda_agent_config_fields(self, mtrl_trainer):
+    def test_lambda_agent_config_fields(self, mtrl_trainer, test_config):
         """Verify Lambda agent uses CustomAgentLambdaConfig (not LambdaConfig)."""
         lambda_arn = "arn:aws:lambda:us-east-1:060795915353:function:SageMaker-agent-adapter-gsm8k"
         evaluator = MultiTurnRLEvaluator(
             model=mtrl_trainer,
-            dataset=TEST_CONFIG["dataset"],
-            s3_output_path=f'{TEST_CONFIG["s3_output_path"]}integ-fields-lambda/',
-            mlflow_resource_arn=TEST_CONFIG["mlflow_resource_arn"],
-            role=TEST_CONFIG["role"],
-            region=TEST_CONFIG["region"],
+            dataset=test_config["dataset"],
+            s3_output_path=f'{test_config["s3_output_path"]}integ-fields-lambda/',
+            mlflow_resource_arn=test_config["mlflow_resource_arn"],
+            role=test_config["role"],
+            region=test_config["region"],
             agent_config=lambda_arn,
         )
 
         evaluator._resolve_trainer_defaults()
         evaluator._resolve_agent_arn()
 
         ctx = evaluator._build_template_context(
-            aws_context={"region": TEST_CONFIG["region"], "account_id": _ACCOUNT_ID,
-                         "role_arn": TEST_CONFIG["role"]},
+            aws_context={"region": test_config["region"], "account_id": test_config["account_id"],
+                         "role_arn": test_config["role"]},
             artifacts={},
-            model_package_group_arn=TEST_CONFIG["model_package_group"],
+            model_package_group_arn=test_config["model_package_group"],
         )
 
         doc = json.loads(ctx["job_config_document_ft_str"])
@@ -198,26 +203,26 @@ def test_lambda_agent_config_fields(self, mtrl_trainer):
         # Ensure old field name is NOT present
         assert "LambdaConfig" not in agent_cfg
 
-    def test_model_package_config_fields(self, mtrl_trainer):
+    def test_model_package_config_fields(self, mtrl_trainer, test_config):
         """Verify ModelPackageConfig uses InputModelPackageArn only (no OutputModelPackageGroupArn for eval)."""
         evaluator = MultiTurnRLEvaluator(
             model=mtrl_trainer,
-            dataset=TEST_CONFIG["dataset"],
-            s3_output_path=f'{TEST_CONFIG["s3_output_path"]}integ-fields-mpc/',
-            mlflow_resource_arn=TEST_CONFIG["mlflow_resource_arn"],
-            role=TEST_CONFIG["role"],
-            region=TEST_CONFIG["region"],
-            agent_config=TEST_CONFIG["agent_arn"],
+            dataset=test_config["dataset"],
+            s3_output_path=f'{test_config["s3_output_path"]}integ-fields-mpc/',
+            mlflow_resource_arn=test_config["mlflow_resource_arn"],
+            role=test_config["role"],
+            region=test_config["region"],
+            agent_config=test_config["agent_arn"],
         )
 
         evaluator._resolve_trainer_defaults()
         evaluator._resolve_agent_arn()
 
         ctx = evaluator._build_template_context(
-            aws_context={"region": TEST_CONFIG["region"], "account_id": _ACCOUNT_ID,
-                         "role_arn": TEST_CONFIG["role"]},
+            aws_context={"region": test_config["region"], "account_id": test_config["account_id"],
+                         "role_arn": test_config["role"]},
             artifacts={},
-            model_package_group_arn=TEST_CONFIG["model_package_group"],
+            model_package_group_arn=test_config["model_package_group"],
         )
 
         doc = json.loads(ctx["job_config_document_ft_str"])
@@ -239,41 +244,41 @@ class TestMTRLEvaluatorIntegration:
     in accounts with the feature flag enabled (e.g., 742774200982).
     """
 
-    def test_evaluator_construction_with_trainer(self, mtrl_trainer):
+    def test_evaluator_construction_with_trainer(self, mtrl_trainer, test_config):
         """Test that MultiTurnRLEvaluator can be constructed from a trainer."""
         evaluator = MultiTurnRLEvaluator(
             model=mtrl_trainer,
-            dataset=TEST_CONFIG["dataset"],
-            s3_output_path=f'{TEST_CONFIG["s3_output_path"]}integ-construct/',
-            mlflow_resource_arn=TEST_CONFIG["mlflow_resource_arn"],
-            role=TEST_CONFIG["role"],
-            region=TEST_CONFIG["region"],
-            agent_config=TEST_CONFIG["agent_arn"],
+            dataset=test_config["dataset"],
+            s3_output_path=f'{test_config["s3_output_path"]}integ-construct/',
+            mlflow_resource_arn=test_config["mlflow_resource_arn"],
+            role=test_config["role"],
+            region=test_config["region"],
+            agent_config=test_config["agent_arn"],
         )
 
         assert evaluator is not None
         assert evaluator.model is mtrl_trainer
-        assert evaluator.dataset == TEST_CONFIG["dataset"]
-        assert evaluator.region == TEST_CONFIG["region"]
+        assert evaluator.dataset == test_config["dataset"]
+        assert evaluator.region == test_config["region"]
 
-    def test_evaluator_construction_with_base_model(self):
+    def test_evaluator_construction_with_base_model(self, test_config):
         """Test that MultiTurnRLEvaluator can be constructed from a base model string."""
         evaluator = MultiTurnRLEvaluator(
-            model=TEST_CONFIG["base_model"],
-            dataset=TEST_CONFIG["dataset"],
-            s3_output_path=f'{TEST_CONFIG["s3_output_path"]}integ-base/',
-            agent_config=TEST_CONFIG["agent_arn"],
-            mlflow_resource_arn=TEST_CONFIG["mlflow_resource_arn"],
-            role=TEST_CONFIG["role"],
-            region=TEST_CONFIG["region"],
+            model=test_config["base_model"],
+            dataset=test_config["dataset"],
+            s3_output_path=f'{test_config["s3_output_path"]}integ-base/',
+            agent_config=test_config["agent_arn"],
+            mlflow_resource_arn=test_config["mlflow_resource_arn"],
+            role=test_config["role"],
+            region=test_config["region"],
         )
 
         assert evaluator is not None
-        assert evaluator.model == TEST_CONFIG["base_model"]
+        assert evaluator.model == test_config["base_model"]
 
-    def test_get_all_mtrl_evaluations(self):
+    def test_get_all_mtrl_evaluations(self, test_config):
         """Test listing all MTRL evaluation executions."""
-        all_execs = MultiTurnRLEvaluator.get_all(region=TEST_CONFIG["region"])
+        all_execs = MultiTurnRLEvaluator.get_all(region=test_config["region"])
 
         if hasattr(all_execs, '__iter__'):
             all_execs = list(all_execs)