Techdebt: Get regions from SSM instead of Boto3

MANIFEST.in

@@ -1,6 +1,7 @@
 include README.md LICENSE AUTHORS.md
 include requirements.txt requirements-dev.txt
 include moto/config/resources/aws_managed_rules.json
+include moto/core/regions.json
 include moto/ec2/_models/*.py
 include moto/ec2/resources/instance_types.json
 include moto/ec2/resources/instance_type_offerings/*/*.json

moto/budgets/models.py

@@ -141,5 +141,5 @@ def describe_notifications_for_budget(
 
 
 budgets_backends = BackendDict(
-    BudgetsBackend, "budgets", use_boto3_regions=False, additional_regions=["global"]
+    BudgetsBackend, "budgets", use_ssm_regions=False, additional_regions=["global"]
 )

moto/ce/models.py

@@ -153,5 +153,5 @@ def untag_resource(self, resource_arn: str, tag_keys: List[str]) -> None:
 
 
 ce_backends = BackendDict(
-    CostExplorerBackend, "ce", use_boto3_regions=False, additional_regions=["global"]
+    CostExplorerBackend, "ce", use_ssm_regions=False, additional_regions=["global"]
 )

moto/cloudfront/models.py

@@ -432,6 +432,6 @@ def delete_origin_access_control(self, control_id: str) -> None:
 cloudfront_backends = BackendDict(
     CloudFrontBackend,
     "cloudfront",
-    use_boto3_regions=False,
+    use_ssm_regions=False,
     additional_regions=["global"],
 )

moto/core/base_backend.py

@@ -1,15 +1,18 @@
-from boto3 import Session
 import re
 import string
 from functools import lru_cache
 from threading import RLock
 from typing import Any, List, Dict, Optional, ClassVar, TypeVar, Iterator
 from uuid import uuid4
 from moto.settings import allow_unknown_region, enable_iso_regions
+from moto.utilities.utils import load_resource
 from .model_instances import model_data
 from .utils import convert_regex_to_flask_path
 
 
+regions_by_service = load_resource(__name__, "regions.json")
+
+
 class InstanceTrackerMeta(type):
     def __new__(meta, name: str, bases: Any, dct: Dict[str, Any]) -> type:
         cls = super(InstanceTrackerMeta, meta).__new__(meta, name, bases, dct)
@@ -191,19 +194,17 @@ def __init__(
         service_name: str,
         account_id: str,
         backend: type,
-        use_boto3_regions: bool,
+        use_ssm_regions: bool,
         additional_regions: Optional[List[str]],
     ):
         self.service_name = service_name
         self.account_id = account_id
         self.backend = backend
         self.regions = []
-        if use_boto3_regions:
-            sess = Session()
-            for partition in sess.get_available_partitions():
-                self.regions.extend(
-                    sess.get_available_regions(service_name, partition_name=partition)
-                )
+        if use_ssm_regions:
+            self.regions.extend(
+                regions_by_service.get(service_name) or regions_by_service["__all"]
+            )
         self.regions.extend(additional_regions or [])
         self._id = str(uuid4())
 
@@ -268,12 +269,12 @@ def __init__(
         self,
         backend: Any,
         service_name: str,
-        use_boto3_regions: bool = True,
+        use_ssm_regions: bool = True,
         additional_regions: Optional[List[str]] = None,
     ):
         self.backend = backend
         self.service_name = service_name
-        self._use_boto3_regions = use_boto3_regions
+        self._use_ssm_regions = use_ssm_regions
         self._additional_regions = additional_regions
         self._id = str(uuid4())
 
@@ -312,6 +313,6 @@ def _create_account_specific_backend(self, account_id: str) -> None:
                     service_name=self.service_name,
                     account_id=account_id,
                     backend=self.backend,
-                    use_boto3_regions=self._use_boto3_regions,
+                    use_ssm_regions=self._use_ssm_regions,
                     additional_regions=self._additional_regions,
                 )

moto/dynamodb_v20111205/models.py

@@ -393,6 +393,6 @@ def update_item(
 dynamodb_backends = BackendDict(
     DynamoDBBackend,
     "dynamodb_v20111205",
-    use_boto3_regions=False,
+    use_ssm_regions=False,
     additional_regions=["global"],
 )

moto/iam/models.py

@@ -3310,5 +3310,5 @@ def get_service_linked_role_deletion_status(self) -> bool:
 
 
 iam_backends = BackendDict(
-    IAMBackend, "iam", use_boto3_regions=False, additional_regions=["global"]
+    IAMBackend, "iam", use_ssm_regions=False, additional_regions=["global"]
 )

moto/instance_metadata/models.py

@@ -8,6 +8,6 @@ class InstanceMetadataBackend(BaseBackend):
 instance_metadata_backends = BackendDict(
     InstanceMetadataBackend,
     "instance_metadata",
-    use_boto3_regions=False,
+    use_ssm_regions=False,
     additional_regions=["global"],
 )

moto/organizations/models.py

@@ -940,6 +940,6 @@ def remove_account_from_organization(self, **kwargs: str) -> None:
 organizations_backends = BackendDict(
     OrganizationsBackend,
     "organizations",
-    use_boto3_regions=False,
+    use_ssm_regions=False,
     additional_regions=["global"],
 )

moto/route53/models.py

@@ -929,5 +929,5 @@ def get_reusable_delegation_set(self, delegation_set_id: str) -> DelegationSet:
 
 
 route53_backends = BackendDict(
-    Route53Backend, "route53", use_boto3_regions=False, additional_regions=["global"]
+    Route53Backend, "route53", use_ssm_regions=False, additional_regions=["global"]
 )

moto/s3/models.py

@@ -2619,16 +2619,16 @@ def __init__(
         self,
         backend: Any,
         service_name: str,
-        use_boto3_regions: bool = True,
+        use_ssm_regions: bool = True,
         additional_regions: Optional[List[str]] = None,
     ):
-        super().__init__(backend, service_name, use_boto3_regions, additional_regions)
+        super().__init__(backend, service_name, use_ssm_regions, additional_regions)
 
         # Maps bucket names to account IDs. This is used to locate the exact S3Backend
         # holding the bucket and to maintain the common bucket namespace.
         self.bucket_accounts: Dict[str, str] = {}
 
 
 s3_backends = S3BackendDict(
-    S3Backend, service_name="s3", use_boto3_regions=False, additional_regions=["global"]
+    S3Backend, service_name="s3", use_ssm_regions=False, additional_regions=["global"]
 )

moto/s3control/models.py

@@ -142,6 +142,6 @@ def get_access_point_policy_status(self, account_id: str, name: str) -> bool:
 s3control_backends = BackendDict(
     S3ControlBackend,
     "s3control",
-    use_boto3_regions=False,
+    use_ssm_regions=False,
     additional_regions=["global"],
 )

moto/sts/models.py

@@ -198,5 +198,5 @@ def _create_access_key(self, role: str) -> Tuple[str, AccessKey]:
 
 
 sts_backends = BackendDict(
-    STSBackend, "sts", use_boto3_regions=False, additional_regions=["global"]
+    STSBackend, "sts", use_ssm_regions=False, additional_regions=["global"]
 )

moto/support/models.py

@@ -224,5 +224,5 @@ def describe_cases(
 
 
 support_backends = BackendDict(
-    SupportBackend, "support", use_boto3_regions=False, additional_regions=["us-east-1"]
+    SupportBackend, "support", use_ssm_regions=False, additional_regions=["us-east-1"]
 )

scripts/ssm_get_default_params.py

@@ -4,9 +4,23 @@
 import subprocess
 import time
 
+import moto
+from moto.utilities.utils import load_resource
 from moto.ssm.utils import convert_to_tree
 
 
+root_dir = subprocess.check_output(["git", "rev-parse", "--show-toplevel"]).decode().strip()
+
+
+alt_names = {
+    "lambda": "awslambda",
+    "aps": "amp",  # Prometheus
+    "costexplorer": "ce",
+    "waf": "wafv2",
+    "identitystore": "ssoadmin"
+}
+
+
 def retrieve_by_path(client, path):
     print(f"Retrieving all parameters from {path}. "
           f"AWS has around 14000 parameters, and we can only retrieve 10 at the time, so this may take a while.\n\n")
@@ -44,17 +58,38 @@ def main():
     for path in default_param_paths:
         params = retrieve_by_path(client, path)
         tree = convert_to_tree(params)
-        root_dir = (
-            subprocess.check_output(["git", "rev-parse", "--show-toplevel"])
-                .decode()
-                .strip()
-        )
+
         filename = "{}.json".format(path.split("/")[-1])
         dest = os.path.join(root_dir, "moto/ssm/resources/{}".format(filename))
         print("Writing data to {0}".format(dest))
         with open(dest, "w") as open_file:
             json.dump(tree, open_file, sort_keys=True, indent=2)
 
+    services = load_resource(moto.__name__, "ssm/resources/services.json")["aws"]["service"]["global-infrastructure"]["services"]
+    all_regions = set()
+    for service in services.keys():
+        all_regions.update(list(services[service].get("regions", {}).keys()))
+
+    regions_by_service = {"__all": list(all_regions)}
+    for service in services.keys():
+        regions = set(services[service].get("regions", {}).keys())
+        if regions != set(regions_by_service["__all"]):
+            clean_name = alt_names.get(service, service).replace("-", "")
+            if f"mock_{clean_name}" in dir(moto):
+                regions_by_service[service] = sorted(regions)
+
+    dest = os.path.join(root_dir, "moto/core/regions.json")
+    print("Writing data to {0}".format(dest))
+    with open(dest, "w") as open_file:
+        # Yes, json.dump exists
+        # But this gives us more control over the indentation options
+        open_file.write("{\n")
+        for idx, key in enumerate(sorted(regions_by_service.keys())):
+            open_file.write(f"  \"{key}\": [")
+            open_file.write(", ".join([f"\"{s}\"" for s in sorted(regions_by_service[key])]))
+            open_file.write("]\n" if (idx == len(regions_by_service.keys())-1) else "],\n")
+        open_file.write("}")
+
 
 if __name__ == "__main__":
     main()

tests/test_core/test_backenddict.py

@@ -57,7 +57,7 @@ def test_backend_dict_can_retrieve_for_specific_account():
 
 
 def test_backend_dict_can_ignore_boto3_regions():
-    backend_dict = BackendDict(ExampleBackend, "ec2", use_boto3_regions=False)
+    backend_dict = BackendDict(ExampleBackend, "ec2", use_ssm_regions=False)
     assert backend_dict["account"].get("us-east-1") is None
 
 
@@ -143,7 +143,7 @@ def _create_asb(account_id, backend=None, use_boto3_regions=False, regions=None)
         service_name="ec2",
         account_id=account_id,
         backend=backend or ExampleBackend,
-        use_boto3_regions=use_boto3_regions,
+        use_ssm_regions=use_boto3_regions,
         additional_regions=regions,
     )