RDS: db instance identifier validation (#6519)

moto/rds/exceptions.py

@@ -192,3 +192,12 @@ class InvalidGlobalClusterStateFault(RDSClientError):
         super().__init__(
             "InvalidGlobalClusterStateFault", f"Global Cluster {arn} is not empty"
         )
+
+
+class InvalidDBInstanceIdentifier(InvalidParameterValue):
+    def __init__(self) -> None:
+        super().__init__(
+            "The parameter DBInstanceIdentifier 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."
+        )

moto/rds/models.py

@@ -1,6 +1,7 @@
 import copy
 import datetime
 import os
+import re
 import string
 
 from collections import defaultdict
@@ -33,6 +34,7 @@ from .exceptions import (
     InvalidParameterValue,
     InvalidParameterCombination,
     InvalidDBClusterStateFault,
+    InvalidDBInstanceIdentifier,
     InvalidGlobalClusterStateFault,
     ExportTaskNotFoundError,
     ExportTaskAlreadyExistsError,
@@ -921,7 +923,7 @@ class Database(CloudFormationModel):
             "availability_zone": properties.get("AvailabilityZone"),
             "backup_retention_period": properties.get("BackupRetentionPeriod"),
             "db_instance_class": properties.get("DBInstanceClass"),
-            "db_instance_identifier": resource_name,
+            "db_instance_identifier": resource_name.replace("_", "-"),
             "db_name": properties.get("DBName"),
             "preferred_backup_window": properties.get(
                 "PreferredBackupWindow", "13:14-13:44"
@@ -1562,6 +1564,7 @@ class RDSBackend(BaseBackend):
 
     def create_db_instance(self, db_kwargs: Dict[str, Any]) -> Database:
         database_id = db_kwargs["db_instance_identifier"]
+        self._validate_db_identifier(database_id)
         database = Database(**db_kwargs)
 
         cluster_id = database.db_cluster_identifier
@@ -1742,6 +1745,7 @@ class RDSBackend(BaseBackend):
     def stop_db_instance(
         self, db_instance_identifier: str, db_snapshot_identifier: Optional[str] = None
     ) -> Database:
+        self._validate_db_identifier(db_instance_identifier)
         database = self.describe_db_instances(db_instance_identifier)[0]
         # todo: certain rds types not allowed to be stopped at this time.
         # https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_StopInstance.html#USER_StopInstance.Limitations
@@ -1758,6 +1762,7 @@ class RDSBackend(BaseBackend):
         return database
 
     def start_db_instance(self, db_instance_identifier: str) -> Database:
+        self._validate_db_identifier(db_instance_identifier)
         database = self.describe_db_instances(db_instance_identifier)[0]
         # todo: bunch of different error messages to be generated from this api call
         if database.status != "stopped":
@@ -1780,6 +1785,7 @@ class RDSBackend(BaseBackend):
     def delete_db_instance(
         self, db_instance_identifier: str, db_snapshot_name: Optional[str] = None
     ) -> Database:
+        self._validate_db_identifier(db_instance_identifier)
         if db_instance_identifier in self.databases:
             if self.databases[db_instance_identifier].deletion_protection:
                 raise InvalidParameterValue(
@@ -2588,6 +2594,19 @@ class RDSBackend(BaseBackend):
         tags_dict.update({d["Key"]: d["Value"] for d in new_tags})
         return [{"Key": k, "Value": v} for k, v in tags_dict.items()]
 
+    @staticmethod
+    def _validate_db_identifier(db_identifier: str) -> None:
+        # https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBInstance.html
+        # Constraints:
+        # # 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
+        ):
+            return
+        raise InvalidDBInstanceIdentifier
+
     def describe_orderable_db_instance_options(
         self, engine: str, engine_version: str
     ) -> List[Dict[str, Any]]:

tests/test_rds/test_rds_cloudformation.py

@@ -144,7 +144,7 @@ def test_rds_db_parameter_groups():
         Parameters=[
             {"ParameterKey": key, "ParameterValue": value}
             for key, value in [
-                ("DBInstanceIdentifier", "master_db"),
+                ("DBInstanceIdentifier", "master-db"),
                 ("DBName", "my_db"),
                 ("DBUser", "my_user"),
                 ("DBPassword", "my_password"),
@@ -188,11 +188,12 @@ def test_rds_mysql_with_read_replica():
 
     template_json = json.dumps(rds_mysql_with_read_replica.template)
     cf = boto3.client("cloudformation", "us-west-1")
+    db_identifier = "master-db"
     cf.create_stack(
         StackName="test_stack",
         TemplateBody=template_json,
         Parameters=[
-            {"ParameterKey": "DBInstanceIdentifier", "ParameterValue": "master_db"},
+            {"ParameterKey": "DBInstanceIdentifier", "ParameterValue": db_identifier},
             {"ParameterKey": "DBName", "ParameterValue": "my_db"},
             {"ParameterKey": "DBUser", "ParameterValue": "my_user"},
             {"ParameterKey": "DBPassword", "ParameterValue": "my_password"},
@@ -205,27 +206,27 @@ def test_rds_mysql_with_read_replica():
 
     rds = boto3.client("rds", region_name="us-west-1")
 
-    primary = rds.describe_db_instances(DBInstanceIdentifier="master_db")[
+    primary = rds.describe_db_instances(DBInstanceIdentifier=db_identifier)[
         "DBInstances"
     ][0]
-    primary.should.have.key("MasterUsername").equal("my_user")
+    assert primary["MasterUsername"] == "my_user"
-    primary.should.have.key("AllocatedStorage").equal(20)
+    assert primary["AllocatedStorage"] == 20
-    primary.should.have.key("DBInstanceClass").equal("db.m1.medium")
+    assert primary["DBInstanceClass"] == "db.m1.medium"
-    primary.should.have.key("MultiAZ").equal(True)
+    assert primary["MultiAZ"]
-    primary.should.have.key("ReadReplicaDBInstanceIdentifiers").being.length_of(1)
+    assert len(primary["ReadReplicaDBInstanceIdentifiers"]) == 1
     replica_id = primary["ReadReplicaDBInstanceIdentifiers"][0]
 
     replica = rds.describe_db_instances(DBInstanceIdentifier=replica_id)["DBInstances"][
         0
     ]
-    replica.should.have.key("DBInstanceClass").equal("db.m1.medium")
+    assert replica["DBInstanceClass"] == "db.m1.medium"
 
     security_group_name = primary["DBSecurityGroups"][0]["DBSecurityGroupName"]
     security_group = rds.describe_db_security_groups(
         DBSecurityGroupName=security_group_name
     )["DBSecurityGroups"][0]
-    security_group["EC2SecurityGroups"][0]["EC2SecurityGroupName"].should.equal(
+    assert (
-        "application"
+        security_group["EC2SecurityGroups"][0]["EC2SecurityGroupName"] == "application"
     )
 
 
@@ -235,11 +236,12 @@ def test_rds_mysql_with_read_replica():
 def test_rds_mysql_with_read_replica_in_vpc():
     template_json = json.dumps(rds_mysql_with_read_replica.template)
     cf = boto3.client("cloudformation", "eu-central-1")
+    db_identifier = "master-db"
     cf.create_stack(
         StackName="test_stack",
         TemplateBody=template_json,
         Parameters=[
-            {"ParameterKey": "DBInstanceIdentifier", "ParameterValue": "master_db"},
+            {"ParameterKey": "DBInstanceIdentifier", "ParameterValue": db_identifier},
             {"ParameterKey": "DBName", "ParameterValue": "my_db"},
             {"ParameterKey": "DBUser", "ParameterValue": "my_user"},
             {"ParameterKey": "DBPassword", "ParameterValue": "my_password"},
@@ -250,7 +252,7 @@ def test_rds_mysql_with_read_replica_in_vpc():
     )
 
     rds = boto3.client("rds", region_name="eu-central-1")
-    primary = rds.describe_db_instances(DBInstanceIdentifier="master_db")[
+    primary = rds.describe_db_instances(DBInstanceIdentifier=db_identifier)[
         "DBInstances"
     ][0]