FIX:Add secrets Manager Tag resource Funtionality (#3392)

* FIX:Add secrets Manager Tag resoruce Funtionality

* Fixed review comments

Co-authored-by: usmankb <usman@krazybee.com>

moto/secretsmanager/models.py

@@ -565,6 +565,19 @@ class SecretsManagerBackend(BaseBackend):
 
         return secret.arn, secret.name
 
+    def tag_resource(self, secret_id, tags):
+
+        if secret_id not in self.secrets.keys():
+            raise SecretNotFoundException()
+
+        secret = self.secrets[secret_id]
+        old_tags = secret.tags
+
+        for tag in tags:
+            old_tags.append(tag)
+
+        return secret_id
+
     @staticmethod
     def get_resource_policy(secret_id):
         resource_policy = {

moto/secretsmanager/responses.py

@@ -157,3 +157,8 @@ class SecretsManagerResponse(BaseResponse):
         return secretsmanager_backends[self.region].get_resource_policy(
             secret_id=secret_id
         )
+
+    def tag_resource(self):
+        secret_id = self._get_param("SecretId")
+        tags = self._get_param("Tags", if_none=[])
+        return secretsmanager_backends[self.region].tag_resource(secret_id, tags)

tests/test_secretsmanager/test_secretsmanager.py

@@ -912,3 +912,33 @@ def test_update_secret_marked_as_deleted_after_restoring():
     assert updated_secret["ARN"]
     assert updated_secret["Name"] == "test-secret"
     assert updated_secret["VersionId"] != ""
+
+
+@mock_secretsmanager
+def test_tag_resource():
+    conn = boto3.client("secretsmanager", region_name="us-west-2")
+    conn.create_secret(Name="test-secret", SecretString="foosecret")
+    conn.tag_resource(
+        SecretId="test-secret", Tags=[{"Key": "FirstTag", "Value": "SomeValue"},],
+    )
+
+    conn.tag_resource(
+        SecretId="test-secret", Tags=[{"Key": "SecondTag", "Value": "AnotherValue"},],
+    )
+
+    secrets = conn.list_secrets()
+    assert secrets["SecretList"][0].get("Tags") == [
+        {"Key": "FirstTag", "Value": "SomeValue"},
+        {"Key": "SecondTag", "Value": "AnotherValue"},
+    ]
+
+    with assert_raises(ClientError) as cm:
+        conn.tag_resource(
+            SecretId="dummy-test-secret",
+            Tags=[{"Key": "FirstTag", "Value": "SomeValue"},],
+        )
+
+    assert_equal(
+        "Secrets Manager can't find the specified secret.",
+        cm.exception.response["Error"]["Message"],
+    )