Add support for roles.

migra/changes.py

@@ -19,6 +19,8 @@ THINGS = [
     "collations",
     "rlspolicies",
     "triggers",
+    "roles",
+    "memberships",
 ]
 PK = "PRIMARY KEY"
 

migra/command.py

@@ -48,6 +48,13 @@ def parse_args(args):
         default=False,
         help="Also output privilege differences (ie. grant/revoke statements)",
     )
+    parser.add_argument(
+        "--with-roles",
+        dest="with_roles",
+        action="store_true",
+        default=False,
+        help='Also output "create/drop role" statements.',
+    )
     parser.add_argument(
         "--force-utf8",
         dest="force_utf8",
@@ -75,7 +82,7 @@ def run(args, out=None, err=None):
         if args.create_extensions_only:
             m.add_extension_changes(drops=False)
         else:
-            m.add_all_changes(privileges=args.with_privileges)
+            m.add_all_changes(privileges=args.with_privileges, roles=args.with_roles)
         try:
             if m.statements:
                 if args.force_utf8:

migra/migra.py

@@ -1,8 +1,7 @@
 from __future__ import unicode_literals
 
-from sqlbag import raw_execute
-
 from schemainspect import DBInspector, get_inspector
+from sqlbag import raw_execute
 
 from .changes import Changes
 from .statements import Statements
@@ -62,7 +61,13 @@ class Migration(object):
         if drops:
             self.add(self.changes.extensions(drops_only=True))
 
-    def add_all_changes(self, privileges=False):
+    def add_all_changes(self, privileges=False, roles=False):
+        if roles:
+            if privileges:
+                self.add(self.changes.memberships(drops_only=True))
+            self.add(self.changes.roles(drops_only=True))
+            self.add(self.changes.roles(creations_only=True))
+
         self.add(self.changes.schemas(creations_only=True))
 
         self.add(self.changes.extensions(creations_only=True))
@@ -87,6 +92,8 @@ class Migration(object):
         self.add(self.changes.non_pk_constraints(creations_only=True))
         if privileges:
             self.add(self.changes.privileges(creations_only=True))
+            if roles:
+                self.add(self.changes.memberships(creations_only=True))
         self.add(self.changes.rlspolicies(creations_only=True))
         self.add(self.changes.triggers(creations_only=True))
         self.add(self.changes.collations(drops_only=True))