From f7230984f658c48b9a9af13e844a335c3736e904 Mon Sep 17 00:00:00 2001
From: Guillaume Abrioux <gabrioux@redhat.com>
Date: Wed, 1 Feb 2017 16:05:14 +0100
Subject: [PATCH] ceph-detect-init: Add docker detection

if running `ceph-detect-init` from a container, the given output is the
reference from the hosting system. This patch add the capability of
detecting if the tool is being run inside a container.

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
---
 .../ceph_detect_init/__init__.py              | 17 +++++++++
 .../ceph_detect_init/docker/__init__.py       |  3 ++
 src/ceph-detect-init/tests/test_all.py        | 37 +++++++++++++++++++
 3 files changed, 57 insertions(+)
 create mode 100644 src/ceph-detect-init/ceph_detect_init/docker/__init__.py

diff --git a/src/ceph-detect-init/ceph_detect_init/__init__.py b/src/ceph-detect-init/ceph_detect_init/__init__.py
index b431616cedfc..aad3eee5a77a 100644
--- a/src/ceph-detect-init/ceph_detect_init/__init__.py
+++ b/src/ceph-detect-init/ceph_detect_init/__init__.py
@@ -23,6 +23,8 @@ from ceph_detect_init import rhel
 from ceph_detect_init import suse
 from ceph_detect_init import gentoo
 from ceph_detect_init import freebsd
+from ceph_detect_init import docker
+import os
 import logging
 import platform
 
@@ -69,6 +71,7 @@ def _get_distro(distro, use_rhceph=False):
         'funtoo': gentoo,
         'exherbo': gentoo,
         'freebsd': freebsd,
+        'docker': docker,
     }
 
     if distro == 'redhat' and use_rhceph:
@@ -94,6 +97,20 @@ def _normalized_distro_name(distro):
 
 def platform_information():
     """detect platform information from remote host."""
+    try:
+        file_name = '/proc/self/cgroup'
+        with open(file_name, 'r') as f:
+            lines = f.readlines()
+            for line in lines:
+                if "docker" in line.split(':')[2]:
+                    return ('docker', 'docker', 'docker')
+    except Exception as err:
+        logging.debug("platform_information: ",
+                      "Error while opening %s : %s" % (file_name, err))
+
+    if os.path.isfile('/.dockerenv'):
+        return ('docker', 'docker', 'docker')
+
     if platform.system() == 'Linux':
         linux_distro = platform.linux_distribution(
             supported_dists=platform._supported_dists + ('alpine', 'arch'))
diff --git a/src/ceph-detect-init/ceph_detect_init/docker/__init__.py b/src/ceph-detect-init/ceph_detect_init/docker/__init__.py
new file mode 100644
index 000000000000..30e838eeb83b
--- /dev/null
+++ b/src/ceph-detect-init/ceph_detect_init/docker/__init__.py
@@ -0,0 +1,3 @@
+def choose_init():
+    """Returns 'none' because we are running in a container"""
+    return 'none'
diff --git a/src/ceph-detect-init/tests/test_all.py b/src/ceph-detect-init/tests/test_all.py
index a81ec980843a..d2733c32957c 100644
--- a/src/ceph-detect-init/tests/test_all.py
+++ b/src/ceph-detect-init/tests/test_all.py
@@ -34,6 +34,7 @@ from ceph_detect_init import rhel
 from ceph_detect_init import suse
 from ceph_detect_init import gentoo
 from ceph_detect_init import freebsd
+from ceph_detect_init import docker
 
 logging.basicConfig(format='%(asctime)s %(levelname)s %(message)s',
                     level=logging.DEBUG)
@@ -50,6 +51,9 @@ class TestCephDetectInit(testtools.TestCase):
     def test_freebsd(self):
         self.assertEqual('bsdrc', freebsd.choose_init())
 
+    def test_docker(self):
+        self.assertEqual('none', docker.choose_init())
+
     def test_centos(self):
         with mock.patch('ceph_detect_init.centos.release',
                         '7.0'):
@@ -262,6 +266,39 @@ class TestCephDetectInit(testtools.TestCase):
             self.assertEqual(('debian', 'sid/jessie', 'sid'),
                              ceph_detect_init.platform_information())
 
+    @mock.patch('platform.linux_distribution')
+    def test_platform_information_container(self, mock_linux_dist):
+        import sys
+        if sys.version_info >= (3, 0):
+            mocked_fn = 'builtins.open'
+        else:
+            mocked_fn = '__builtin__.open'
+
+        with mock.patch(mocked_fn,
+                        mock.mock_open(read_data="""1:name=systemd:/system.slice \
+                                                 /docker-39cc1fb.scope"""),
+                        create=True) as m:
+            self.assertEqual(('docker',
+                              'docker',
+                              'docker'),
+                             ceph_detect_init.platform_information(),)
+            m.assert_called_once_with('/proc/self/cgroup', 'r')
+
+        with mock.patch(mocked_fn, mock.mock_open(), create=True) as m:
+            m.side_effect = IOError()
+            mock_linux_dist.return_value = ('Red Hat Enterprise Linux Server',
+                                            '7.3', 'Maipo')
+            # Just run the code to validate the code won't raise IOError
+            ceph_detect_init.platform_information()
+
+        with mock.patch('os.path.isfile', mock.MagicMock()) as m:
+            m.return_value = True
+            self.assertEqual(('docker',
+                              'docker',
+                              'docker'),
+                             ceph_detect_init.platform_information(),)
+            m.assert_called_once_with('/.dockerenv')
+
     @mock.patch('platform.system', lambda: 'FreeBSD')
     def test_platform_information_freebsd(self):
         with mock.patch.multiple('platform',
-- 
2.47.3