Implementing IAM policy versions

Adding definitions for create, list, and delete policy_versions

moto/iam/models.py

@@ -43,6 +43,7 @@ class Policy(BaseModel):
         self.id = random_policy_id()
         self.path = path or '/'
         self.default_version_id = default_version_id or 'v1'
+        self.versions = []
 
         self.create_datetime = datetime.now(pytz.utc)
         self.update_datetime = datetime.now(pytz.utc)
@@ -52,6 +53,20 @@ class Policy(BaseModel):
         return 'arn:aws:iam::aws:policy{0}{1}'.format(self.path, self.name)
 
 
+class Version(object):
+
+    def __init__(self,
+                 policy_arn,
+                 document,
+                 is_default_version=False):
+        self.policy_arn = policy_arn
+        self.document = document or {}
+        self.is_default_version = is_default_version
+        self.version_id = 'v1'
+
+        self.create_datetime = datetime.now(pytz.utc)
+
+
 class ManagedPolicy(Policy):
     """Managed policy."""
 
@@ -536,6 +551,15 @@ class IAMBackend(BaseBackend):
 
         return policies, marker
 
+    def get_policy(self, policy_name):
+        policy = self.managed_policies[policy_name]
+        if not policy:
+            raise IAMNotFoundException("Policy {0} not found".format(policy_name))
+        return policy
+
+    def get_policies(self):
+        return self.managed_policies.values()
+
     def create_role(self, role_name, assume_role_policy_document, path):
         role_id = random_resource_id()
         role = Role(role_id, role_name, assume_role_policy_document, path)
@@ -568,6 +592,24 @@ class IAMBackend(BaseBackend):
         role = self.get_role(role_name)
         return role.policies.keys()
 
+    def create_policy_version(self, policy_arn, policy_document, set_as_default):
+        policy_name = policy_arn.split(':')[-1]
+        policy_name = policy_name.split('/')[1]
+        policy = self.get_policy(policy_name)
+        version = Version(policy_arn, policy_document, set_as_default)
+        policy.versions.append(version)
+        if set_as_default:
+            policy.default_version_id = version.version_id
+
+    def delete_policy_version(self, policy_arn, version_id):
+        policy_name = policy_arn.split(':')[-1]
+        policy_name = policy_name.split('/')[1]
+        policy = self.get_policy(policy_name)
+        for i, v in enumerate(policy.versions):
+            if v.version_id == version_id:
+                del policy.versions[i]
+                return
+
     def create_instance_profile(self, name, path, role_ids):
         instance_profile_id = random_resource_id()