Merge lp:~blake-rouse/maas/fix-interface-container-discovery into lp:~maas-committers/maas/trunk

[Blake Rouse]

Revert r4795 as it was doing the wrong thing. Fix the running_in_container function to correctly detect that process is running in a container. Uses systemd-detect-virt which includes all the logic to determine this information.

[Gavin Panella (allenap)]

I don't understand how this fixes the linked bug, but it looks fine.

review: Approve

[Blake Rouse (blake-rouse)]

Thanks for the review. I added the lru_cache decorator and fixes the tests to clear it.

[MAAS Lander (maas-lander)]

The attempt to merge lp:~blake-rouse/maas/fix-interface-container-discovery into lp:maas failed. Below is the output from the failed tests.

Hit:1 http://security.ubuntu.com/ubuntu xenial-security InRelease
Get:2 http://prodstack-zone-2.clouds.archive.ubuntu.com/ubuntu xenial InRelease [116 kB]
Hit:3 http://prodstack-zone-2.clouds.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:4 http://prodstack-zone-2.clouds.archive.ubuntu.com/ubuntu xenial-backports InRelease
Get:5 http://prodstack-zone-2.clouds.archive.ubuntu.com/ubuntu xenial/main Sources [1,105 kB]
Get:6 http://prodstack-zone-2.clouds.archive.ubuntu.com/ubuntu xenial/universe Sources [7,509 kB]
Get:7 http://prodstack-zone-2.clouds.archive.ubuntu.com/ubuntu xenial/main amd64 Packages [1,435 kB]
Get:8 http://prodstack-zone-2.clouds.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages [7,241 kB]
Fetched 17.4 MB in 3s (5,297 kB/s)
Reading package lists...
sudo DEBIAN_FRONTEND=noninteractive apt-get -y \
    --no-install-recommends install apache2 archdetect-deb authbind bind9 bind9utils build-essential bzr-builddeb chromium-browser chromium-chromedriver curl daemontools debhelper dh-apport dh-systemd distro-info dnsutils firefox freeipmi-tools git gjs ipython isc-dhcp-common libjs-angularjs libjs-jquery libjs-jquery-hotkeys libjs-yui3-full libjs-yui3-min libpq-dev make nodejs-legacy npm postgresql pxelinux python3-all python3-apt python3-bson python3-convoy python3-coverage python3-crochet python3-cssselect python3-curtin python3-dev python3-distro-info python3-django python3-django-nose python3-django-piston3 python3-dnspython python3-docutils python3-formencode python3-hivex python3-httplib2 python3-jinja2 python3-jsonschema python3-lxml python3-mock python3-netaddr python3-netifaces python3-oauth python3-oauthlib python3-openssl python3-paramiko python3-petname python3-pexpect python3-psycopg2 python3-pyinotify python3-pyparsing python3-pyvmomi python3-requests python3-seamicroclient python3-setuptools python3-simplestreams python3-sphinx python3-tempita python3-twisted python3-txtftp python3-tz python3-yaml python3-zope.interface python-bson python-crochet python-django python-django-piston python-djorm-ext-pgarray python-formencode python-lxml python-netaddr python-netifaces python-pocket-lint python-psycopg2 python-tempita python-twisted python-yaml socat syslinux-common tgt ubuntu-cloudimage-keyring wget xvfb
Reading package lists...
Building dependency tree...
Reading state information...
apache2 is already the newest version (2.4.18-1ubuntu1).
archdetect-deb is already the newest version (1.114ubuntu3).
authbind is already the newest version (2.1.1+nmu1).
bind9 is already the newest version (1:9.10.3.dfsg.P2-5).
bind9utils is already the newest version (1:9.10.3.dfsg.P2-5).
build-essential is already the newest version (12.1ubuntu2).
curl is already the newest version (7.47.0-1ubuntu2).
debhelper is already the newest version (9.20160115ubuntu2).
dh-apport is already the newest version (2.20-0ubuntu3).
dh-systemd is already the newest version (1.29ubuntu1).
distro-info is already the newest version (0.14build1).
dnsutils is already the newest version (1:9.10.3.dfsg.P2-5)...

=== modified file 'src/provisioningserver/utils/network.py'
--- src/provisioningserver/utils/network.py	2016-03-16 19:27:17 +0000
+++ src/provisioningserver/utils/network.py	2016-03-17 18:23:46 +0000
@@ -625,28 +625,12 @@
     exclude_types = ["loopback", "ipip"]
     if not running_in_container():
         exclude_types.append("ethernet")
-    original_ipaddr_info = get_ip_addr()
     ipaddr_info = {
         name: ipaddr
-        for name, ipaddr in original_ipaddr_info.items()
+        for name, ipaddr in get_ip_addr().items()
         if (ipaddr["type"] not in exclude_types and
             not ipaddr["type"].startswith("unknown-"))
     }
-
-    # It's not always 100% that we can determine that this machine is running
-    # in a container. To handle this case we include "ethernet" interfaces
-    # when no other interfaces could be identified. See lp:1554999.
-    if len(ipaddr_info) == 0 and "ethernet" in exclude_types:
-        # No interfaces have been discovered from "ip addr" excluding
-        # "ethernet". Re-filter including ethernet.
-        exclude_types.remove("ethernet")
-        ipaddr_info = {
-            name: ipaddr
-            for name, ipaddr in original_ipaddr_info.items()
-            if (ipaddr["type"] not in exclude_types and
-                not ipaddr["type"].startswith("unknown-"))
-        }
-
     for name, ipaddr in ipaddr_info.items():
         iface_type = "physical"
         parents = []

=== modified file 'src/provisioningserver/utils/ps.py'
--- src/provisioningserver/utils/ps.py	2016-03-07 23:20:52 +0000
+++ src/provisioningserver/utils/ps.py	2016-03-17 18:23:46 +0000
@@ -7,9 +7,14 @@
     'running_in_container',
     ]
 
+from functools import lru_cache
 import os
 
 from provisioningserver.utils.fs import read_text_file
+from provisioningserver.utils.shell import (
+    call_and_check,
+    ExternalProcessError,
+)
 
 
 def is_pid_in_container(pid, proc_path="/proc"):
@@ -28,9 +33,17 @@
     return False
 
 
-def running_in_container(proc_path="/proc"):
+@lru_cache(maxsize=1)
+def running_in_container():
     """Return True if running in an LXC or Docker container."""
-    return is_pid_in_container(1, proc_path=proc_path)
+    try:
+        call_and_check(["systemd-detect-virt", "-c"])
+    except ExternalProcessError:
+        # Exited non-zero so not in a container.
+        return False
+    else:
+        # Exited zero so inside a container.
+        return True
 
 
 def get_running_pids_with_command(
@@ -56,7 +69,7 @@
                 pids.append(int(pid))
 
     if (exclude_container_processes and
-            not running_in_container(proc_path=proc_path)):
+            not running_in_container()):
         return [
             pid
             for pid in pids

=== modified file 'src/provisioningserver/utils/tests/test_network.py'
--- src/provisioningserver/utils/tests/test_network.py	2016-03-16 19:27:17 +0000
+++ src/provisioningserver/utils/tests/test_network.py	2016-03-17 18:23:46 +0000
@@ -837,14 +837,8 @@
         }
         self.assertInterfacesResult(ip_addr, {}, {}, MatchesDict({}))
 
-    def test__ignores_ethernet_when_physical(self):
+    def test__ignores_ethernet(self):
         ip_addr = {
-            "eth0": {
-                "type": "ethernet.physical",
-                "mac": factory.make_mac_address(),
-                "flags": ["UP"],
-                "inet": [],
-            },
             "vnet": {
                 "type": "ethernet",
                 "mac": factory.make_mac_address(),
@@ -852,38 +846,7 @@
                 "inet": ["192.168.122.2/24"],
             },
         }
-        expected_result = MatchesDict({
-            "eth0": MatchesDict({
-                "type": Equals("physical"),
-                "mac_address": Equals(ip_addr["eth0"]["mac"]),
-                "enabled": Is(True),
-                "parents": Equals([]),
-                "links": Equals([]),
-                "source": Equals("ipaddr"),
-            }),
-        })
-        self.assertInterfacesResult(ip_addr, {}, {}, expected_result)
-
-    def test__includes_ethernet_when_only_ethernet(self):
-        ip_addr = {
-            "vnet": {
-                "type": "ethernet",
-                "mac": factory.make_mac_address(),
-                "flags": ["UP"],
-                "inet": [],
-            },
-        }
-        expected_result = MatchesDict({
-            "vnet": MatchesDict({
-                "type": Equals("physical"),
-                "mac_address": Equals(ip_addr["vnet"]["mac"]),
-                "enabled": Is(True),
-                "parents": Equals([]),
-                "links": Equals([]),
-                "source": Equals("ipaddr"),
-            }),
-        })
-        self.assertInterfacesResult(ip_addr, {}, {}, expected_result)
+        self.assertInterfacesResult(ip_addr, {}, {}, MatchesDict({}))
 
     def test__ignores_ipip(self):
         ip_addr = {

=== modified file 'src/provisioningserver/utils/tests/test_ps.py'
--- src/provisioningserver/utils/tests/test_ps.py	2016-03-07 23:20:52 +0000
+++ src/provisioningserver/utils/tests/test_ps.py	2016-03-17 18:23:46 +0000
@@ -11,12 +11,14 @@
 
 from maastesting.factory import factory
 from maastesting.testcase import MAASTestCase
+from provisioningserver.utils import ps as ps_module
 from provisioningserver.utils.fs import atomic_write
 from provisioningserver.utils.ps import (
     get_running_pids_with_command,
     is_pid_in_container,
     running_in_container,
 )
+from provisioningserver.utils.shell import ExternalProcessError
 
 
 NOT_IN_CONTAINER = dedent("""\
@@ -92,30 +94,17 @@
 
 class TestRunningInContainer(MAASTestCase):
 
-    scenarios = (
-        ("not_in_container", {
-            "result": False,
-            "cgroup": NOT_IN_CONTAINER,
-        }),
-        ("in_docker_container", {
-            "result": True,
-            "cgroup": IN_DOCKER_CONTAINER,
-        }),
-        ("in_lxc_container", {
-            "result": True,
-            "cgroup": IN_LXC_CONTAINER,
-        }),
-    )
+    def test__returns_False_when_ExternalProcessError(self):
+        mock_call = self.patch(ps_module, "call_and_check")
+        mock_call.side_effect = ExternalProcessError(
+            1, ["systemd-detect-virt", "-c"], output="none")
+        running_in_container.cache_clear()
+        self.assertFalse(running_in_container())
 
-    def test__result(self):
-        proc_path = self.make_dir()
-        pid_path = os.path.join(proc_path, "1")
-        os.mkdir(pid_path)
-        atomic_write(
-            self.cgroup.encode("ascii"),
-            os.path.join(pid_path, "cgroup"))
-        self.assertEqual(
-            self.result, running_in_container(proc_path=proc_path))
+    def test__returns_True_when_not_ExternalProcessError(self):
+        self.patch(ps_module, "call_and_check")
+        running_in_container.cache_clear()
+        self.assertTrue(running_in_container())
 
 
 class TestGetRunningPIDsWithCommand(MAASTestCase):
@@ -162,6 +151,9 @@
             self.make_process(
                 proc_path, pid,
                 in_container=True, command=command)
+        mock_running_in_container = self.patch(
+            ps_module, "running_in_container")
+        mock_running_in_container.return_value = False
         self.assertItemsEqual(
             pids_running_command,
             get_running_pids_with_command(command, proc_path=proc_path))
@@ -201,6 +193,9 @@
             self.make_process(
                 proc_path, pid,
                 in_container=True, command=factory.make_name("command"))
+        mock_running_in_container = self.patch(
+            ps_module, "running_in_container")
+        mock_running_in_container.return_value = True
         self.assertItemsEqual(
             pids_running_command,
             get_running_pids_with_command(command, proc_path=proc_path))