Merge ~ltrager/maas:lp1705508_2.2 into maas:2.2

[Lee Trager]

Set the no_proxy environment variable to 127.0.0.1,localhost.

When MAAS starts importing boot resources it sets the proxy environment
variables for the whole process, if an external proxy is set. No exceptions were made for 127.0.0.1 or localhost. Region refresh sends results to itself over HTTP. Because no exceptions were allowed region refresh failed.

Fixes: LP: #1705508
Backport: 027666bfbc56fbd52ebcd40ac0d9e71a9d4cc41e

[Lee Trager (ltrager)]

Approved in https://code.launchpad.net/~ltrager/maas/+git/maas/+merge/328054

review: Approve

[MAAS Lander (maas-lander)]

LANDING
-b lp1705508_2.2 lp:~ltrager/maas into -b 2.2 lp:~maas-committers/maas

STATUS: FAILED BUILD
LOG: http://maas-ci-jenkins.internal:8080/job/maas/job/branch-tester/159/console

diff --git a/src/maasserver/bootsources.py b/src/maasserver/bootsources.py
index 999a6d8..6ad2bf7 100644
--- a/src/maasserver/bootsources.py
+++ b/src/maasserver/bootsources.py
@@ -87,6 +87,11 @@ def get_simplestreams_env():
         if http_proxy is not None:
             env['http_proxy'] = http_proxy
             env['https_proxy'] = http_proxy
+            # When the proxy environment variables are set they effect the
+            # entire process, including controller refresh. When the region
+            # needs to refresh itself it sends itself results over HTTP to
+            # 127.0.0.1.
+            env['no_proxy'] = '127.0.0.1,localhost'
     return env
 
 
diff --git a/src/maasserver/tests/test_bootsources.py b/src/maasserver/tests/test_bootsources.py
index ecba7ce..66b0b96 100644
--- a/src/maasserver/tests/test_bootsources.py
+++ b/src/maasserver/tests/test_bootsources.py
@@ -253,8 +253,10 @@ class TestPrivateCacheBootSources(MAASTransactionServerTestCase):
         factory.make_BootSource(keyring_data=b'1234')
         cache_boot_sources()
         self.assertEqual(
-            (proxy_address, proxy_address),
-            (capture.env['http_proxy'], capture.env['https_proxy']))
+            (proxy_address, proxy_address, '127.0.0.1,localhost'),
+            (
+                capture.env['http_proxy'], capture.env['https_proxy'],
+                capture.env['no_proxy']))
 
     def test__passes_user_agent_with_maas_version(self):
         mock_download = self.patch(