Write secrets to tmpfs

So that we may avoid writing the decrypted contents of secrets to
disk, write them to a file in a tmpfs.

Change-Id: I7c029b67d0fc2fa3827dc811137dd4f3a90706d8
diff --git a/tests/unit/test_bubblewrap.py b/tests/unit/test_bubblewrap.py
index bb1be73..661d868 100644
--- a/tests/unit/test_bubblewrap.py
+++ b/tests/unit/test_bubblewrap.py
@@ -39,8 +39,8 @@
         ssh_agent.start()
         po = context.getPopen(work_dir=work_dir,
                               ssh_auth_sock=ssh_agent.env['SSH_AUTH_SOCK'])
-        self.assertTrue(po.passwd_r > 2)
-        self.assertTrue(po.group_r > 2)
+        self.assertTrue(po.fds[0] > 2)
+        self.assertTrue(po.fds[1] > 2)
         self.assertTrue(work_dir in po.command)
         # Now run /usr/bin/id to verify passwd/group entries made it in
         true_proc = po(['/usr/bin/id'], stdout=subprocess.PIPE,
@@ -51,8 +51,7 @@
         # And that it did not print things on stderr
         self.assertEqual(0, len(errs.strip()))
         # Make sure the _r's are closed
-        self.assertIsNone(po.passwd_r)
-        self.assertIsNone(po.group_r)
+        self.assertEqual([], po.fds)
 
     def test_bubblewrap_leak(self):
         bwrap = bubblewrap.BubblewrapDriver()
diff --git a/tests/unit/test_v3.py b/tests/unit/test_v3.py
index 2293ca0..eb11edf 100755
--- a/tests/unit/test_v3.py
+++ b/tests/unit/test_v3.py
@@ -1283,8 +1283,7 @@
         ], ordered=False)
         matches = self.searchForContent(self.history[0].jobdir.root,
                                         b'test-password')
-        self.assertEqual(set(['/ansible/playbook_0/secrets.yaml',
-                              '/work/secret-file.txt']),
+        self.assertEqual(set(['/work/secret-file.txt']),
                          set(matches))
 
     def test_secret_file(self):
@@ -1319,8 +1318,7 @@
         ], ordered=False)
         matches = self.searchForContent(self.history[0].jobdir.root,
                                         b'test-password')
-        self.assertEqual(set(['/ansible/playbook_0/secrets.yaml',
-                              '/work/failure-file.txt']),
+        self.assertEqual(set(['/work/failure-file.txt']),
                          set(matches))
 
     def test_secret_file_fail(self):