refactor init_clients in sam delete

samcli/commands/delete/delete_context.py

@@ -5,21 +5,21 @@
 import logging
 from typing import Optional
 
-import boto3
 import click
+from botocore.exceptions import NoCredentialsError, NoRegionError
 from click import confirm, prompt
 
 from samcli.cli.cli_config_file import TomlProvider
-from samcli.cli.context import Context
 from samcli.commands.delete.exceptions import CfDeleteFailedStatusError
+from samcli.commands.exceptions import AWSServiceClientError, RegionError
 from samcli.lib.bootstrap.companion_stack.companion_stack_builder import CompanionStack
 from samcli.lib.delete.cfn_utils import CfnUtils
 from samcli.lib.package.artifact_exporter import Template
 from samcli.lib.package.ecr_uploader import ECRUploader
 from samcli.lib.package.local_files_utils import get_uploaded_s3_object_name
 from samcli.lib.package.s3_uploader import S3Uploader
 from samcli.lib.package.uploaders import Uploaders
-from samcli.lib.utils.boto_utils import get_boto_config_with_user_agent
+from samcli.lib.utils.boto_utils import get_boto_client_provider_with_config
 
 CONFIG_COMMAND = "deploy"
 CONFIG_SECTION = "parameters"
@@ -108,38 +108,29 @@ def init_clients(self):
         """
         Initialize all the clients being used by sam delete.
         """
-        if not self.region:
-            if not self.no_prompts:
-                session = boto3.Session()
-                region = session.region_name
-                self.region = region if region else "us-east-1"
-            else:
-                # TODO: as part of the guided and non-guided context separation, we need also to move the options
-                # validations to a validator similar to samcli/lib/cli_validation/image_repository_validation.py.
-                raise click.BadOptionUsage(
-                    option_name="--region",
-                    message="Missing option '--region', region is required to run the non guided delete command.",
-                )
-
-        if self.profile:
-            Context.get_current_context().profile = self.profile
-        if self.region:
-            Context.get_current_context().region = self.region
-
-        boto_config = get_boto_config_with_user_agent()
-
-        # Define cf_client based on the region as different regions can have same stack-names
-        cloudformation_client = boto3.client(
-            "cloudformation", region_name=self.region if self.region else None, config=boto_config
+        client_provider = get_boto_client_provider_with_config(
+            region=self.region if self.region else None, profile=self.profile if self.profile else None
         )
 
-        s3_client = boto3.client("s3", region_name=self.region if self.region else None, config=boto_config)
-        ecr_client = boto3.client("ecr", region_name=self.region if self.region else None, config=boto_config)
+        try:
+            cloudformation_client = client_provider("cloudformation")
+            s3_client = client_provider("s3")
+            ecr_client = client_provider("ecr")
+        except NoCredentialsError as ex:
+            raise AWSServiceClientError(
+                "Unable to resolve credentials for the AWS SDK for Python client. "
+                "Please see their documentation for options to pass in credentials: "
+                "https://boto3.amazonaws.com/v1/documentation/api/latest/guide/configuration.html"
+            ) from ex
+        except NoRegionError as ex:
+            raise RegionError(
+                "Unable to resolve a region. "
+                "Please provide a region via the --region, via --profile or by the "
+                "AWS_DEFAULT_REGION environment variable."
+            ) from ex
 
         self.s3_uploader = S3Uploader(s3_client=s3_client, bucket_name=self.s3_bucket, prefix=self.s3_prefix)
-
         self.ecr_uploader = ECRUploader(docker_client=None, ecr_client=ecr_client, ecr_repo=None, ecr_repo_multi=None)
-
         self.uploaders = Uploaders(self.s3_uploader, self.ecr_uploader)
         self.cf_utils = CfnUtils(cloudformation_client)
 

tests/unit/commands/delete/test_delete_context.py

@@ -1,15 +1,17 @@
 from samcli.lib.bootstrap.companion_stack.data_types import CompanionStack
 from unittest import TestCase
-from unittest.mock import patch, call, MagicMock
+from unittest.mock import patch, call, MagicMock, Mock
 
 import click
+from botocore.exceptions import NoCredentialsError, NoRegionError
 
 from samcli.commands.delete.delete_context import DeleteContext
 from samcli.lib.package.artifact_exporter import Template
 from samcli.cli.cli_config_file import TomlProvider
 from samcli.lib.delete.cfn_utils import CfnUtils
 from samcli.lib.package.s3_uploader import S3Uploader
 from samcli.lib.package.ecr_uploader import ECRUploader
+from samcli.commands.exceptions import AWSServiceClientError, RegionError
 
 from samcli.commands.delete.exceptions import CfDeleteFailedStatusError
 
@@ -518,3 +520,47 @@ def test_s3_option_flag_overrides_config(self, patched_boto3):
         ) as delete_context:
             self.assertEqual(delete_context.s3_bucket, "s3_bucket_override")
             self.assertEqual(delete_context.s3_prefix, "s3_prefix_override")
+
+    @patch.object(DeleteContext, "parse_config_file", MagicMock())
+    @patch("samcli.commands.delete.delete_context.click.get_current_context")
+    @patch("samcli.commands.delete.delete_context.get_boto_client_provider_with_config")
+    def test_must_throw_error_if_boto3_cannot_resolve_credentials(
+        self, get_boto_client_provider_mock, patched_get_current_context
+    ):
+        boto_client_mock = Mock(side_effect=NoCredentialsError)
+        get_boto_client_provider_mock.return_value = boto_client_mock
+        with self.assertRaises(AWSServiceClientError) as ex:
+            with DeleteContext(
+                stack_name="test",
+                region=None,
+                config_file=None,
+                config_env=None,
+                profile="profile_without_creds",
+                no_prompts=True,
+                s3_bucket=None,
+                s3_prefix=None,
+            ):
+                get_boto_client_provider_mock.assert_called_once_with(region=None, profile="profile_without_creds")
+                self.assertIn("Unable to resolve credentials for the AWS SDK for Python client", ex)
+
+    @patch.object(DeleteContext, "parse_config_file", MagicMock())
+    @patch("samcli.commands.delete.delete_context.click.get_current_context")
+    @patch("samcli.commands.delete.delete_context.get_boto_client_provider_with_config")
+    def test_must_throw_error_if_boto3_cannot_resolve_region(
+        self, get_boto_client_provider_mock, patched_get_current_context
+    ):
+        boto_client_mock = Mock(side_effect=NoRegionError)
+        get_boto_client_provider_mock.return_value = boto_client_mock
+        with self.assertRaises(RegionError) as ex:
+            with DeleteContext(
+                stack_name="test",
+                region=None,
+                config_file=None,
+                config_env=None,
+                profile="profile_without_region",
+                no_prompts=True,
+                s3_bucket=None,
+                s3_prefix=None,
+            ):
+                get_boto_client_provider_mock.assert_called_once_with(region=None, profile="profile_without_region")
+                self.assertIn("Unable to resolve a region", ex)