Repository: getmoto/moto
Pull request #8369 (2024-12-05 21:18:47)

Core: Only instantiate Session when required
See https://github.com/getmoto/moto/issues/5469#issuecomment-2474897120

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All modified and coverable lines are covered by tests :white_check_mark:
> Project coverage is 94.59%. Comparing base [(`8fc0045`)](https://app.codecov.io/gh/getmoto/moto/commit/8fc0045cd065dca312a5947f98f761e5a31dd9c1?dropdown=coverage&el=desc&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=getmoto) to head [(`873a3bf`)](https://app.codecov.io/gh/getmoto/moto/commit/873a3bfacb9a2cc2abb200bef0ca798cfb6a7d84?dropdown=coverage&el=desc&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=getmoto).
> Report is 13 commits behind head on master.

<details><summary>Additional details and impacted files</summary>


```diff
@@           Coverage Diff            @@
##           master    #8369    +/-   ##
========================================
  Coverage   94.58%   94.59%            
========================================
  Files        1159     1159            
  Lines      101139   101299   +160     
========================================
+ Hits        95665    95819   +154     
- Misses       5474     5480     +6     
```

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|---|---|---|
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</details>

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Patch:
diff --git a/moto/core/base_backend.py b/moto/core/base_backend.py
index 59c92a851..cc637e70b 100644
--- a/moto/core/base_backend.py
+++ b/moto/core/base_backend.py
@@ -210,8 +210,6 @@ class AccountSpecificBackend(Dict[str, SERVICE_BACKEND]):
       account_specific_backend[region: str] = backend: BaseBackend
     """
 
-    session = Session()
-
     def __init__(
         self,
         service_name: str,
@@ -232,13 +230,25 @@ class AccountSpecificBackend(Dict[str, SERVICE_BACKEND]):
     @lru_cache()
     def _generate_regions(self, service_name: str) -> List[str]:
         regions = []
-        for partition in AccountSpecificBackend.session.get_available_partitions():
-            partition_regions = AccountSpecificBackend.session.get_available_regions(
-                service_name, partition_name=partition
+        for (
+            partition
+        ) in AccountSpecificBackend.get_session().get_available_partitions():
+            partition_regions = (
+                AccountSpecificBackend.get_session().get_available_regions(
+                    service_name, partition_name=partition
+                )
             )
             regions.extend(partition_regions)
         return regions
 
+    @classmethod
+    @lru_cache()
+    def get_session(cls) -> Session:  # type: ignore[misc]
+        # Only instantiate Session when we absolutely need it
+        # This gives the user time to remove any env variables that break botocore, like AWS_PROFILE
+        # See https://github.com/getmoto/moto/issues/5469#issuecomment-2474897120
+        return Session()
+
     def __hash__(self) -> int:  # type: ignore[override]
         return hash(self._id)
 
diff --git a/moto/rds/exceptions.py b/moto/rds/exceptions.py
index 1829bc3f0..f76efba4b 100644
--- a/moto/rds/exceptions.py
+++ b/moto/rds/exceptions.py
@@ -212,6 +212,23 @@ class InvalidDBInstanceIdentifier(InvalidParameterValue):
         )
 
 
+class InvalidDBSnapshotIdentifier(InvalidParameterValue):
+    def __init__(self, snapshot_identifier: str, parameter_name: str) -> None:
+        if snapshot_identifier == "":
+            exception_text = f"The parameter {parameter_name} must be provided and must not be blank."
+        elif not snapshot_identifier[0].isalpha():
+            # On AWS, this error message seems to be triggered when the first character is invalid.
+            # The two spaces before the snapshot_identifier are what AWS produces!
+            exception_text = f"Invalid snapshot identifier:  {snapshot_identifier}"
+        else:
+            exception_text = (
+                f"The parameter {parameter_name} is not a valid identifier. "
+                "Identifiers must begin with a letter; must contain only ASCII letters, digits, and hyphens; "
+                "and must not end with a hyphen or contain two consecutive hyphens."
+            )
+        super().__init__(exception_text)
+
+
 class InvalidDBInstanceEngine(InvalidParameterCombination):
     def __init__(self, instance_engine: str, cluster_engine: str) -> None:
         super().__init__(
diff --git a/moto/rds/models.py b/moto/rds/models.py
index a65d69ad3..a894b04cc 100644
--- a/moto/rds/models.py
+++ b/moto/rds/models.py
@@ -39,6 +39,7 @@ from .exceptions import (
     InvalidDBInstanceEngine,
     InvalidDBInstanceIdentifier,
     InvalidDBInstanceStateError,
+    InvalidDBSnapshotIdentifier,
     InvalidExportSourceStateError,
     InvalidGlobalClusterStateFault,
     InvalidParameterCombination,
@@ -1952,8 +1953,10 @@ class RDSBackend(BaseBackend):
             db_instance_identifier=None, db_snapshot_identifier=from_snapshot_id
         )[0]
         original_database = snapshot.database
-        new_instance_props = copy.deepcopy(original_database.__dict__)
-        new_instance_props.pop("backend")
+        new_instance_props = {}
+        for key, value in original_database.__dict__.items():
+            if key != "backend":
+                new_instance_props[key] = copy.deepcopy(value)
         if not original_database.option_group_supplied:
             # If the option group is not supplied originally, the 'option_group_name' will receive a default value
             # Force this reconstruction, and prevent any validation on the default value
@@ -2719,12 +2722,34 @@ class RDSBackend(BaseBackend):
         # # Must contain from 1 to 63 letters, numbers, or hyphens.
         # # First character must be a letter.
         # # Can't end with a hyphen or contain two consecutive hyphens.
-        if re.match(
-            "^(?!.*--)([a-zA-Z]?[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])$", db_identifier
+        if (
+            re.match(
+                "^(?!.*--)([a-zA-Z]?[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])$", db_identifier
+            )
+            and db_identifier[0].isalpha()
         ):
             return
         raise InvalidDBInstanceIdentifier
 
+    @staticmethod
+    def validate_db_snapshot_identifier(
+        db_snapshot_identifier: str, parameter_name: str
+    ) -> None:
+        # https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBSnapshot.html
+        # Constraints:
+        # # Must contain from 1 to 255 letters, numbers, or hyphens.
+        # # First character must be a letter.
+        # # Can't end with a hyphen or contain two consecutive hyphens.
+        if (
+            re.match(
+                "^(?!.*--)([a-zA-Z]?[a-zA-Z0-9-]{0,253}[a-zA-Z0-9])$",
+                db_snapshot_identifier,
+            )
+            and db_snapshot_identifier[0].isalpha()
+        ):
+            return
+        raise InvalidDBSnapshotIdentifier(db_snapshot_identifier, parameter_name)
+
     def describe_orderable_db_instance_options(
         self, engine: str, engine_version: str
     ) -> List[Dict[str, Any]]:
diff --git a/moto/rds/responses.py b/moto/rds/responses.py
index fabafe7fa..a972a2473 100644
--- a/moto/rds/responses.py
+++ b/moto/rds/responses.py
@@ -277,6 +277,11 @@ class RDSResponse(BaseResponse):
     def delete_db_instance(self) -> str:
         db_instance_identifier = self._get_param("DBInstanceIdentifier")
         db_snapshot_name = self._get_param("FinalDBSnapshotIdentifier")
+        if db_snapshot_name is not None:
+            self.backend.validate_db_snapshot_identifier(
+                db_snapshot_name, parameter_name="FinalDBSnapshotIdentifier"
+            )
+
         database = self.backend.delete_db_instance(
             db_instance_identifier, db_snapshot_name
         )
@@ -293,8 +298,13 @@ class RDSResponse(BaseResponse):
         db_instance_identifier = self._get_param("DBInstanceIdentifier")
         db_snapshot_identifier = self._get_param("DBSnapshotIdentifier")
         tags = self.unpack_list_params("Tags", "Tag")
+        self.backend.validate_db_snapshot_identifier(
+            db_snapshot_identifier, parameter_name="DBSnapshotIdentifier"
+        )
         snapshot = self.backend.create_db_snapshot(
-            db_instance_identifier, db_snapshot_identifier, tags=tags
+            db_instance_identifier,
+            db_snapshot_identifier,
+            tags=tags,
         )
         template = self.response_template(CREATE_SNAPSHOT_TEMPLATE)
         return template.render(snapshot=snapshot)
@@ -304,6 +314,10 @@ class RDSResponse(BaseResponse):
         target_snapshot_identifier = self._get_param("TargetDBSnapshotIdentifier")
         tags = self.unpack_list_params("Tags", "Tag")
         copy_tags = self._get_param("CopyTags")
+        self.backend.validate_db_snapshot_identifier(
+            target_snapshot_identifier, parameter_name="TargetDBSnapshotIdentifier"
+        )
+
         snapshot = self.backend.copy_db_snapshot(
             source_snapshot_identifier, target_snapshot_identifier, tags, copy_tags
         )
@@ -378,6 +392,11 @@ class RDSResponse(BaseResponse):
     def stop_db_instance(self) -> str:
         db_instance_identifier = self._get_param("DBInstanceIdentifier")
         db_snapshot_identifier = self._get_param("DBSnapshotIdentifier")
+        if db_snapshot_identifier is not None:
+            self.backend.validate_db_snapshot_identifier(
+                db_snapshot_identifier, parameter_name="DBSnapshotIdentifier"
+            )
+
         database = self.backend.stop_db_instance(
             db_instance_identifier, db_snapshot_identifier
         )


Test patch:
diff --git a/tests/test_rds/test_rds.py b/tests/test_rds/test_rds.py
index 7da065ace..50c862452 100644
--- a/tests/test_rds/test_rds.py
+++ b/tests/test_rds/test_rds.py
@@ -7,6 +7,8 @@ from botocore.exceptions import ClientError
 
 from moto import mock_aws
 from moto.core import DEFAULT_ACCOUNT_ID as ACCOUNT_ID
+from moto.rds.exceptions import InvalidDBInstanceIdentifier, InvalidDBSnapshotIdentifier
+from moto.rds.models import RDSBackend
 from tests import aws_verified
 
 DEFAULT_REGION = "us-west-2"
@@ -1221,8 +1223,11 @@ def test_delete_db_snapshot():
         conn.describe_db_snapshots(DBSnapshotIdentifier="snapshot-1")
 
 
+@pytest.mark.parametrize(
+    "custom_db_subnet_group", [True, False], ids=("custom_subnet", "default_subnet")
+)
 @mock_aws
-def test_restore_db_instance_from_db_snapshot():
+def test_restore_db_instance_from_db_snapshot(custom_db_subnet_group: bool):
     conn = boto3.client("rds", region_name=DEFAULT_REGION)
     conn.create_db_instance(
         DBInstanceIdentifier="db-primary-1",
@@ -1240,10 +1245,27 @@ def test_restore_db_instance_from_db_snapshot():
         DBInstanceIdentifier="db-primary-1", DBSnapshotIdentifier="snapshot-1"
     )
 
+    if custom_db_subnet_group:
+        ec2 = boto3.client("ec2", region_name=DEFAULT_REGION)
+        subnets = ec2.describe_subnets()["Subnets"]
+        conn.create_db_subnet_group(
+            DBSubnetGroupName="custom-subnet-group",
+            DBSubnetGroupDescription="xxx",
+            SubnetIds=[subnets[0]["SubnetId"]],
+        )
+
     # restore
-    new_instance = conn.restore_db_instance_from_db_snapshot(
-        DBInstanceIdentifier="db-restore-1", DBSnapshotIdentifier="snapshot-1"
-    )["DBInstance"]
+    kwargs = {
+        "DBInstanceIdentifier": "db-restore-1",
+        "DBSnapshotIdentifier": "snapshot-1",
+    }
+    if custom_db_subnet_group:
+        kwargs["DBSubnetGroupName"] = "custom-subnet-group"
+    new_instance = conn.restore_db_instance_from_db_snapshot(**kwargs)["DBInstance"]
+    if custom_db_subnet_group:
+        assert (
+            new_instance["DBSubnetGroup"]["DBSubnetGroupName"] == "custom-subnet-group"
+        )
     assert new_instance["DBInstanceIdentifier"] == "db-restore-1"
     assert new_instance["DBInstanceClass"] == "db.m1.small"
     assert new_instance["StorageType"] == "gp2"
@@ -2778,6 +2800,46 @@ def test_create_db_instance_with_availability_zone():
     assert resp["DBInstances"][0]["AvailabilityZone"] == availability_zone
 
 
+invalid_identifiers = ("-foo", "foo-", "2foo", "foo--bar", "", "foo_bar")
+invalid_db_identifiers = invalid_identifiers + ("x" * 64,)
+invalid_db_snapshot_identifiers = invalid_identifiers + ("x" * 256,)
+
+
+@pytest.mark.parametrize("invalid_db_identifier", invalid_db_identifiers)
+def test_validate_db_identifier_backend_invalid(invalid_db_identifier):
+    with pytest.raises(InvalidDBInstanceIdentifier):
+        RDSBackend._validate_db_identifier(invalid_db_identifier)
+
+
+@pytest.mark.parametrize(
+    "invalid_db_snapshot_identifier", invalid_db_snapshot_identifiers
+)
+def test_validate_db_snapshot_identifier_backend_invalid(
+    invalid_db_snapshot_identifier,
+):
+    with pytest.raises(InvalidDBSnapshotIdentifier):
+        RDSBackend.validate_db_snapshot_identifier(
+            invalid_db_snapshot_identifier, "DBSnapshotIdentifier"
+        )
+
+
+valid_identifiers = ("f", "foo", "FOO", "FOO-bar-123")
+valid_db_identifiers = valid_identifiers + ("x" * 63,)
+valid_db_snapshot_identifiers = valid_identifiers + ("x" * 255,)
+
+
+@pytest.mark.parametrize("valid_db_identifier", valid_db_identifiers)
+def test_validate_db_identifier_backend_valid(valid_db_identifier):
+    RDSBackend._validate_db_identifier(valid_db_identifier)
+
+
+@pytest.mark.parametrize("valid_db_snapshot_identifier", valid_db_snapshot_identifiers)
+def test_validate_db_snapshot_identifier_backend_valid(valid_db_snapshot_identifier):
+    RDSBackend.validate_db_snapshot_identifier(
+        valid_db_snapshot_identifier, "DBSnapshotIdentifier"
+    )
+
+
 @mock_aws
 def test_validate_db_identifier():
     client = boto3.client("rds", region_name=DEFAULT_REGION)
@@ -2817,6 +2879,97 @@ def test_validate_db_identifier():
     validation_helper(exc)
 
 
+@mock_aws
+def test_validate_db_snapshot_identifier_different_operations():
+    client = boto3.client("rds", region_name=DEFAULT_REGION)
+    db_instance_identifier = "valid-identifier"
+    valid_db_snapshot_identifier = "valid"
+    invalid_db_snapshot_identifier = "--invalid--"
+
+    client.create_db_instance(
+        DBInstanceIdentifier=db_instance_identifier,
+        Engine="postgres",
+        DBName="staging-postgres",
+        DBInstanceClass="db.m1.small",
+    )
+
+    expected_message = f"Invalid snapshot identifier:  {invalid_db_snapshot_identifier}"
+    with pytest.raises(ClientError) as exc:
+        client.create_db_snapshot(
+            DBSnapshotIdentifier=invalid_db_snapshot_identifier,
+            DBInstanceIdentifier=db_instance_identifier,
+        )
+    snapshot_validation_helper(exc, expected_message)
+
+    client.create_db_snapshot(
+        DBSnapshotIdentifier=valid_db_snapshot_identifier,
+        DBInstanceIdentifier=db_instance_identifier,
+    )
+
+    with pytest.raises(ClientError) as exc:
+        client.copy_db_snapshot(
+            SourceDBSnapshotIdentifier=valid_db_snapshot_identifier,
+            TargetDBSnapshotIdentifier=invalid_db_snapshot_identifier,
+        )
+    snapshot_validation_helper(exc, expected_message)
+
+    with pytest.raises(ClientError) as exc:
+        client.stop_db_instance(
+            DBInstanceIdentifier=db_instance_identifier,
+            DBSnapshotIdentifier=invalid_db_snapshot_identifier,
+        )
+    snapshot_validation_helper(exc, expected_message)
+
+    with pytest.raises(ClientError) as exc:
+        client.delete_db_instance(
+            DBInstanceIdentifier=db_instance_identifier,
+            FinalDBSnapshotIdentifier=invalid_db_snapshot_identifier,
+        )
+    snapshot_validation_helper(exc, expected_message)
+
+
+# Depending on what is wrong with the snapshot_identifier, AWS produces different error messages.
+snapshot_identifier_data = (
+    ("", "The parameter DBSnapshotIdentifier must be provided and must not be blank."),
+    ("-invalid", "Invalid snapshot identifier:  -invalid"),
+    (
+        "in--valid",
+        (
+            "The parameter DBSnapshotIdentifier is not a valid identifier. "
+            "Identifiers must begin with a letter; must contain only ASCII "
+            "letters, digits, and hyphens; and must not end with a hyphen "
+            "or contain two consecutive hyphens."
+        ),
+    ),
+)
+
+
+@pytest.mark.parametrize(
+    "invalid_db_snapshot_identifier,expected_message",
+    snapshot_identifier_data,
+    ids=("empty", "invalid_first_character", "default_message"),
+)
+@mock_aws
+def test_validate_db_snapshot_identifier_different_error_messages(
+    invalid_db_snapshot_identifier, expected_message
+):
+    client = boto3.client("rds", region_name=DEFAULT_REGION)
+    db_instance_identifier = "valid-identifier"
+    client.create_db_instance(
+        DBInstanceIdentifier=db_instance_identifier,
+        Engine="postgres",
+        DBName="staging-postgres",
+        DBInstanceClass="db.m1.small",
+    )
+
+    with pytest.raises(ClientError) as exc:
+        client.create_db_snapshot(
+            DBSnapshotIdentifier=invalid_db_snapshot_identifier,
+            DBInstanceIdentifier=db_instance_identifier,
+        )
+    snapshot_validation_helper(exc, expected_message)
+
+
 @mock_aws
 def test_createdb_instance_engine_with_invalid_value():
     client = boto3.client("rds", region_name=DEFAULT_REGION)
@@ -2951,3 +3104,9 @@ def validation_helper(exc):
         "letters, digits, and hyphens; "
         "and must not end with a hyphen or contain two consecutive hyphens."
     )
+
+
+def snapshot_validation_helper(exc, expected_message):
+    err = exc.value.response["Error"]
+    assert err["Code"] == "InvalidParameterValue"
+    assert err["Message"] == expected_message