Tests pass on Python 3.

src/allmydata/grid_manager.py

@@ -334,7 +334,8 @@ def save_grid_manager(file_path, grid_manager, create=True):
             if create:
                 raise
         with file_path.child("config.json").open("w") as f:
-            f.write("{}\n".format(data))
+            f.write(data.encode("utf-8"))
+            f.write(b"\n")
 
 
 def parse_grid_manager_certificate(gm_data):
@@ -465,7 +466,7 @@ def create_grid_manager_verifier(keys, certs, public_key, now_fn=None, bad_cert=
         now = now_fn()
         for cert in valid_certs:
             expires = datetime.utcfromtimestamp(cert['expires'])
-            if cert['public_key'] == public_key:
+            if cert['public_key'].encode("ascii") == public_key:
                 if expires > now:
                     # not-expired
                     return True

src/allmydata/node.py

@@ -534,7 +534,7 @@ class _Config(object):
 
         cert_fnames = list(self.enumerate_section("grid_manager_certificates").values())
         for fname in cert_fnames:
-            fname = self.get_config_path(fname.decode('utf8'))
+            fname = self.get_config_path(fname)
             if not os.path.exists(fname):
                 raise ValueError(
                     "Grid Manager certificate file '{}' doesn't exist".format(

src/allmydata/test/test_grid_manager.py

@@ -3,7 +3,6 @@ from past.builtins import unicode
 from datetime import (
     timedelta,
 )
-import json
 
 from twisted.python.filepath import (
     FilePath,
@@ -22,6 +21,7 @@ from allmydata.crypto import (
 )
 from allmydata.util import (
     base32,
+    jsonbytes as json,
 )
 from allmydata.grid_manager import (
     load_grid_manager,
@@ -173,8 +173,8 @@ class GridManagerVerifier(SyncTestCase):
         self.assertEqual(
             ed25519.verify_signature(
                 gm_key,
-                base32.a2b(cert0.signature.encode("ascii")),
-                cert0.certificate.encode("ascii"),
+                base32.a2b(cert0.signature),
+                cert0.certificate,
             ),
             None
         )
@@ -251,7 +251,7 @@ class GridManagerVerifier(SyncTestCase):
         }
         fp.makedirs()
         with fp.child("config.json").open("w") as f:
-            json.dump(bad_config, f)
+            f.write(json.dumps_bytes(bad_config))
 
         with self.assertRaises(ValueError) as ctx:
             load_grid_manager(fp)
@@ -283,9 +283,9 @@ class GridManagerVerifier(SyncTestCase):
 
         fp.makedirs()
         with fp.child("config.json").open("w") as f:
-            json.dump(config, f)
+            f.write(json.dumps_bytes(config))
         with fp.child("alice.cert.0").open("w") as f:
-            json.dump(bad_cert, f)
+            f.write(json.dumps_bytes(bad_cert))
 
         with self.assertRaises(ValueError) as ctx:
             load_grid_manager(fp)
@@ -306,7 +306,7 @@ class GridManagerVerifier(SyncTestCase):
         }
         fp.makedirs()
         with fp.child("config.json").open("w") as f:
-            json.dump(bad_config, f)
+            f.write(json.dumps_bytes(bad_config))
 
         with self.assertRaises(ValueError) as ctx:
             load_grid_manager(fp)
@@ -327,7 +327,7 @@ class GridManagerVerifier(SyncTestCase):
         }
         fp.makedirs()
         with fp.child("config.json").open("w") as f:
-            json.dump(bad_config, f)
+            f.write(json.dumps_bytes(bad_config))
 
         with self.assertRaises(ValueError) as ctx:
             load_grid_manager(fp)
@@ -352,7 +352,7 @@ class GridManagerVerifier(SyncTestCase):
         }
         fp.makedirs()
         with fp.child("config.json").open("w") as f:
-            json.dump(bad_config, f)
+            f.write(json.dumps_bytes(bad_config))
 
         with self.assertRaises(ValueError) as ctx:
             load_grid_manager(fp)

src/allmydata/test/test_util.py

@@ -559,7 +559,6 @@ class JSONBytes(unittest.TestCase):
         )
 
 
-
 class FakeGetVersion(object):
     """Emulate an object with a get_version."""