From adb64bd97a90c2711d973686a84530f466e04485 Mon Sep 17 00:00:00 2001
From: Jordan Sanders <jordan@jordansanders.com>
Date: Tue, 28 Mar 2023 07:17:56 -0500
Subject: [PATCH] CloudFormation, Logs: Resolve LogGroup physical id and
 attributes (#6125)

* CloudFormation, Logs: Add physical_resource_id to LogGroup

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-logs-loggroup.html#aws-resource-logs-loggroup-return-values

This brings CloudFormation's Ref behavior more in line with actual
AWS behavior. Previously, it returned an instance of a LogGroup model.

I didn't add a test case for this but I'm happy to do so if requested.

* Resolve LogGroup Fn::GetAtt

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-logs-loggroup.html#aws-resource-logs-loggroup-return-values

* Add type annotations

* Add return type annotation

* Updating CloudFormation coverage
---
 CLOUDFORMATION_COVERAGE.md |  3 +--
 moto/logs/models.py        | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/CLOUDFORMATION_COVERAGE.md b/CLOUDFORMATION_COVERAGE.md
index 60619ff07..44f33f1c8 100644
--- a/CLOUDFORMATION_COVERAGE.md
+++ b/CLOUDFORMATION_COVERAGE.md
@@ -272,8 +272,7 @@
    - [x] create implemented
    - [ ] update implemented
    - [ ] delete implemented
-   - [ ] Fn::GetAtt implemented
-      - [ ] Arn
+   - [x] Fn::GetAtt implemented
 - AWS::RDS::DBParameterGroup:
    - [x] create implemented
    - [ ] update implemented
diff --git a/moto/logs/models.py b/moto/logs/models.py
index f3fe935ee..633cb2704 100644
--- a/moto/logs/models.py
+++ b/moto/logs/models.py
@@ -306,6 +306,23 @@ class LogGroup(CloudFormationModel):
             resource_name, tags, **properties
         )
 
+    @classmethod
+    def has_cfn_attr(cls, attr: str) -> bool:
+        return attr in [
+            "Arn",
+        ]
+
+    def get_cfn_attribute(self, attribute_name: str) -> str:
+        from moto.cloudformation.exceptions import UnformattedGetAttTemplateException
+
+        if attribute_name == "Arn":
+            return self.arn
+        raise UnformattedGetAttTemplateException()
+
+    @property
+    def physical_resource_id(self) -> str:
+        return self.name
+
     def create_log_stream(self, log_stream_name: str) -> None:
         if log_stream_name in self.streams:
             raise ResourceAlreadyExistsException()