Merge lp:~gocept/landscape-client/py3-network into lp:~landscape/landscape-client/trunk

[Steffen Allner]

We are on the journey to get the Bytes / String story solved for Python 2/3 compatibility.

This MP considers code in the landscape.lib.network module. This module mostly consists of methods used in this model to retrieve information about network devices. To achieve this, calls to socket methods are used, which require bytes as input. To maintain compatibility with the code using `get_active_device_info` the result of this function still consists of strings in Python 3 but the internal methods now explicitly work on bytes. The `skipped_interfaces` are still a tuple of strings to maintain signature stability.

[🤖 Landscape Builder (landscape-builder)]

review: Abstain (executing tests)

[🤖 Landscape Builder (landscape-builder)]

Command: TRIAL_ARGS=-j4 make check
Result: Fail
Revno: 961
Branch: lp:~gocept/landscape-client/py3-network
Jenkins: https://ci.lscape.net/job/latch-test-precise/899/

review: Needs Fixing (test results)

[🤖 Landscape Builder (landscape-builder)]

review: Abstain (executing tests)

[🤖 Landscape Builder (landscape-builder)]

Command: TRIAL_ARGS=-j4 make check
Result: Fail
Revno: 961
Branch: lp:~gocept/landscape-client/py3-network
Jenkins: https://ci.lscape.net/job/latch-test-xenial/1463/

review: Needs Fixing (test results)

[lp:~gocept/landscape-client/py3-network]

962. By Steffen Allner on 2017-03-09

Only decode with Python 3, otherwise a landscape.schema violation occurs.

963. By Steffen Allner on 2017-03-09

Opening file in binary mode allows to write and load bpickled data.

[Данило Шеган (danilo)]

Looks good but there are a few nits here.

review: Needs Fixing

[🤖 Landscape Builder (landscape-builder)]

review: Abstain (executing tests)

[🤖 Landscape Builder (landscape-builder)]

Command: TRIAL_ARGS=-j4 make check
Result: Success
Revno: 963
Branch: lp:~gocept/landscape-client/py3-network
Jenkins: https://ci.lscape.net/job/latch-test-xenial/3600/

review: Approve (test results)

[Steffen Allner (sallner)]

I merged the current trunk and the py3-fs branch and will resubmit the proposal with a new prerequisite branch.

[lp:~gocept/landscape-client/py3-network]

964. By Steffen Allner on 2017-03-13

Backmerge from trunk.

965. By Steffen Allner on 2017-03-13

Merge landscape.lib.fs with optional encoding.

966. By Steffen Allner on 2017-03-13

Improve documentation.

967. By Steffen Allner on 2017-03-13

Always ensure ascii characters for interface name.

[🤖 Landscape Builder (landscape-builder)]

review: Abstain (executing tests)

[🤖 Landscape Builder (landscape-builder)]

Command: TRIAL_ARGS=-j4 make check
Result: Fail
Revno: 967
Branch: lp:~gocept/landscape-client/py3-network
Jenkins: https://ci.lscape.net/job/latch-test-xenial/3608/

review: Needs Fixing (test results)

[lp:~gocept/landscape-client/py3-network]

968. By Steffen Allner on 2017-03-13

Improve compliance with coding style.

969. By Steffen Allner on 2017-03-14

Merge in current l.l.fs

970. By Steffen Allner on 2017-03-14

Backout former revision 967 as we need a byte string for Python 2 to satisfy the schema.

Unmerged revisions

=== modified file 'landscape/broker/store.py'
--- landscape/broker/store.py	2017-03-06 10:38:07 +0000
+++ landscape/broker/store.py	2017-03-13 13:20:43 +0000
@@ -437,7 +437,7 @@
         return os.path.join(self._directory, *args)
 
     def _get_content(self, filename):
-        file = open(filename)
+        file = open(filename, 'rb')
         try:
             return file.read()
         finally:

=== modified file 'landscape/broker/tests/test_store.py'
--- landscape/broker/tests/test_store.py	2016-08-17 20:31:48 +0000
+++ landscape/broker/tests/test_store.py	2017-03-13 13:20:43 +0000
@@ -280,7 +280,7 @@
         self.store.add({"type": "data", "data": 1})
         # We simulate it by creating a fake file which raises halfway through
         # writing a file.
-        with mock.patch("__builtin__.open") as mock_open:
+        with mock.patch("landscape.lib.fs.open") as mock_open:
             mocked_file = mock_open.return_value
             mocked_file.write.side_effect = IOError("Sorry, pal!")
             # This kind of ensures that raising an exception is somewhat
@@ -288,7 +288,7 @@
             # on special exception-handling in the file-writing code.
             self.assertRaises(
                 IOError, self.store.add, {"type": "data", "data": 2})
-            mock_open.assert_called_with(mock.ANY, "w")
+            mock_open.assert_called_with(mock.ANY, "wb")
             mocked_file.write.assert_called_once_with(mock.ANY)
         self.assertEqual(self.store.get_pending_messages(),
                          [{"type": "data", "data": 1, "api": "3.2"}])

=== modified file 'landscape/lib/fs.py'
--- landscape/lib/fs.py	2013-05-28 08:48:31 +0000
+++ landscape/lib/fs.py	2017-03-13 13:20:43 +0000
@@ -1,50 +1,68 @@
 """File-system utils"""
 
+import codecs
 import os
 import time
 
 
-def create_file(path, content):
+from twisted.python.compat import long
+
+
+def create_file(path, content, encoding=None):
     """Create a file with the given content.
 
     @param path: The path to the file.
     @param content: The content to be written in the file.
+    @param encoding: An optional encoding. If set, the content will be encoded
+        with C{encoding} before writing to the file.
     """
-    fd = open(path, "w")
-    fd.write(content)
-    fd.close()
+    if encoding:
+        content = codecs.encode(content, encoding)
+    # XXX: Due to a very specific mock of `open()` in landscape.broker.tests.\
+    # test_store.MessageStoreTest.test_atomic_message_writing it is hard to
+    # write this file opening as context manager.
+    fd = open(path, "wb")
+    try:
+        fd.write(content)
+    finally:
+        fd.close()
 
 
 def append_file(path, content):
-    """Append a file with the given content.
+    """Append a file with the given binary content.
 
     The file is created, if it doesn't exist already.
 
     @param path: The path to the file.
     @param content: The content to be written in the file at the end.
     """
-    fd = open(path, "a")
-    fd.write(content)
-    fd.close()
-
-
-def read_file(path, limit=None):
+    with open(path, "a") as fd:
+        fd.write(content)
+
+
+def read_file(path, limit=None, encoding=None):
     """Return the content of the given file.
 
     @param path: The path to the file.
     @param limit: An optional read limit. If positive, read up to that number
         of bytes from the beginning of the file. If negative, read up to that
         number of bytes from the end of the file.
-    @return content: The content of the file, possibly trimmed to C{limit}.
+    @param encoding: An optional encoding. If set, the content will be returned
+        decoded with C{encoding}.
+    @return content: The content of the file as bytes or unicode string
+        (depending on C{encoding}), possibly trimmed to C{limit}.
     """
-    fd = open(path, "r")
-    if limit and os.path.getsize(path) > abs(limit):
-        whence = 0
-        if limit < 0:
-            whence = 2
-        fd.seek(limit, whence)
-    content = fd.read()
-    fd.close()
+    # Use binary mode since opening a file in text mode in Python 3 does not
+    # allow non-zero offset seek from the end of the file.
+    with open(path, "rb") as fd:
+        if limit and os.path.getsize(path) > abs(limit):
+            whence = 0
+            if limit < 0:
+                whence = 2
+            fd.seek(limit, whence)
+        content = fd.read()
+    if encoding:
+        content = codecs.decode(content, encoding)
     return content
 
 

=== modified file 'landscape/lib/juju.py'
--- landscape/lib/juju.py	2014-09-24 08:09:55 +0000
+++ landscape/lib/juju.py	2017-03-13 13:20:43 +0000
@@ -13,7 +13,7 @@
     if not os.path.exists(config.juju_filename):
         return
 
-    json_contents = read_file(config.juju_filename)
+    json_contents = read_file(config.juju_filename, encoding="utf-8")
     try:
         juju_info = json.loads(json_contents)
     # Catch any error the json lib could throw, because we don't know or

=== modified file 'landscape/lib/network.py'
--- landscape/lib/network.py	2017-01-10 16:02:02 +0000
+++ landscape/lib/network.py	2017-03-13 13:20:43 +0000
@@ -8,7 +8,7 @@
 import errno
 import logging
 
-from twisted.python.compat import long
+from twisted.python.compat import long, _PY3
 
 __all__ = ["get_active_device_info", "get_network_traffic", "is_64"]
 
@@ -55,7 +55,7 @@
     max_interfaces = 128
 
     # Setup an array to hold our response, and initialized to null strings.
-    interfaces = array.array("B", "\0" * max_interfaces * IF_STRUCT_SIZE)
+    interfaces = array.array("B", b"\0" * max_interfaces * IF_STRUCT_SIZE)
     buffer_size = interfaces.buffer_info()[0]
     packed_bytes = struct.pack(
         "iL", max_interfaces * IF_STRUCT_SIZE, buffer_size)
@@ -69,7 +69,7 @@
     already_found = set()
     for index in range(0, byte_length, IF_STRUCT_SIZE):
         ifreq_struct = result[index:index + IF_STRUCT_SIZE]
-        interface_name = ifreq_struct[:ifreq_struct.index("\0")]
+        interface_name = ifreq_struct[:ifreq_struct.index(b"\0")]
         if interface_name not in already_found:
             already_found.add(interface_name)
             yield interface_name
@@ -121,7 +121,16 @@
     """
     mac_address = fcntl.ioctl(
         sock.fileno(), SIOCGIFHWADDR, struct.pack("256s", interface[:15]))
-    return "".join(["%02x:" % ord(char) for char in mac_address[18:24]])[:-1]
+    if _PY3:
+        def to_int(char):
+            # We have already bytes, so we do nothing
+            return char
+    else:
+        def to_int(char):
+            # We have a string in python 2 and need the int here.
+            return ord(char)
+    return "".join(["%02x:" % to_int(char)
+                    for char in mac_address[18:24]])[:-1]
 
 
 def get_flags(sock, interface):
@@ -147,13 +156,17 @@
         sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM,
                              socket.IPPROTO_IP)
         for interface in get_active_interfaces(sock):
-            if interface in skipped_interfaces:
-                continue
-            if skip_vlan and "." in interface:
-                continue
-            if skip_alias and ":" in interface:
-                continue
-            interface_info = {"interface": interface}
+            interface_string = interface.decode("ascii")
+            if interface_string in skipped_interfaces:
+                continue
+            if skip_vlan and b"." in interface:
+                continue
+            if skip_alias and b":" in interface:
+                continue
+            # We keep values as byte strings for use in struct.pack() in
+            # different getter methods, and only use the decoded value of the
+            # interface name here.
+            interface_info = {"interface": interface_string}
             interface_info["ip_address"] = get_ip_address(sock, interface)
             interface_info["mac_address"] = get_mac_address(sock, interface)
             interface_info["broadcast_address"] = get_broadcast_address(
@@ -175,9 +188,8 @@
     Retrieves an array of information regarding the network activity per
     network interface.
     """
-    netdev = open(source_file, "r")
-    lines = netdev.readlines()
-    netdev.close()
+    with open(source_file, "r") as netdev:
+        lines = netdev.readlines()
 
     # Parse out the column headers as keys.
     _, receive_columns, transmit_columns = lines[1].split("|")
@@ -227,7 +239,7 @@
         * 0: The cable is not connected to the interface. We cannot measure
           interface speed, but could if it was plugged in.
     """
-    cmd_struct = struct.pack('I39s', ETHTOOL_GSET, '\x00' * 39)
+    cmd_struct = struct.pack('I39s', ETHTOOL_GSET, b'\x00' * 39)
     status_cmd = array.array('B', cmd_struct)
     packed = struct.pack('16sP', interface_name, status_cmd.buffer_info()[0])
 

=== modified file 'landscape/lib/tests/test_fs.py'
--- landscape/lib/tests/test_fs.py	2016-06-15 16:42:17 +0000
+++ landscape/lib/tests/test_fs.py	2017-03-13 13:20:43 +0000
@@ -1,7 +1,11 @@
+# -*- coding: utf-8 -*-
+import codecs
 import os
 from mock import patch
 import time
 
+from twisted.python.compat import long
+
 from landscape.tests.helpers import LandscapeTest
 
 from landscape.lib.fs import append_file, read_file, touch_file
@@ -14,7 +18,16 @@
         With no options L{read_file} reads the whole file passed as argument.
         """
         path = self.makeFile("foo")
-        self.assertEqual(read_file(path), "foo")
+        self.assertEqual(read_file(path), b"foo")
+
+    def test_read_file_encoding(self):
+        """
+        With encoding L{read_file} reads the whole file passed as argument and
+        decodes it.
+        """
+        utf8_content = codecs.encode(u"foo \N{SNOWMAN}", "utf-8")
+        path = self.makeFile(utf8_content, mode="wb")
+        self.assertEqual(read_file(path, encoding="utf-8"), u"foo ☃")
 
     def test_read_file_with_limit(self):
         """
@@ -22,14 +35,23 @@
         given limit.
         """
         path = self.makeFile("foo bar")
-        self.assertEqual(read_file(path, limit=3), " bar")
+        self.assertEqual(read_file(path, limit=3), b" bar")
+
+    def test_read_file_with_limit_encoding(self):
+        """
+        With a positive limit L{read_file} reads only the bytes after the
+        given limit.
+        """
+        utf8_content = codecs.encode(u"foo \N{SNOWMAN}", "utf-8")
+        path = self.makeFile(utf8_content, mode="wb")
+        self.assertEqual(read_file(path, limit=3, encoding="utf-8"), u" ☃")
 
     def test_read_file_with_negative_limit(self):
         """
         With a negative limit L{read_file} reads only the tail of the file.
         """
         path = self.makeFile("foo bar from end")
-        self.assertEqual(read_file(path, limit=-3), "end")
+        self.assertEqual(read_file(path, limit=-3), b"end")
 
     def test_read_file_with_limit_bigger_than_file(self):
         """
@@ -37,8 +59,8 @@
         file.
         """
         path = self.makeFile("foo bar from end")
-        self.assertEqual(read_file(path, limit=100), "foo bar from end")
-        self.assertEqual(read_file(path, limit=-100), "foo bar from end")
+        self.assertEqual(read_file(path, limit=100), b"foo bar from end")
+        self.assertEqual(read_file(path, limit=-100), b"foo bar from end")
 
 
 class TouchFileTest(LandscapeTest):

=== modified file 'landscape/lib/tests/test_network.py'
--- landscape/lib/tests/test_network.py	2017-01-23 12:14:33 +0000
+++ landscape/lib/tests/test_network.py	2017-03-13 13:20:43 +0000
@@ -1,14 +1,13 @@
 import array
 import socket
 
-from mock import patch, ANY
+from mock import patch, ANY, mock_open
 from subprocess import Popen, PIPE
 
 from landscape.tests.helpers import LandscapeTest
 from landscape.lib.network import (
     get_network_traffic, get_active_device_info, get_active_interfaces,
     get_fqdn, get_network_interface_speed)
-from landscape.compat import StringIO
 
 
 class NetworkInfoTest(LandscapeTest):
@@ -24,6 +23,7 @@
 
         device_info = get_active_device_info()
         result = Popen(["/sbin/ifconfig"], stdout=PIPE).communicate()[0]
+        result = result.decode('ascii')
         interface_blocks = dict(
             [(block.split()[0], block.upper()) for block in
              filter(None, result.split("\n\n"))])
@@ -62,7 +62,7 @@
     def test_skip_vlan(self, mock_get_active_interfaces):
         """VLAN interfaces are not reported by L{get_active_device_info}."""
         mock_get_active_interfaces.side_effect = lambda sock: (
-            list(get_active_interfaces(sock)) + ["eth0.1"])
+            list(get_active_interfaces(sock)) + [b"eth0.1"])
         device_info = get_active_device_info()
         mock_get_active_interfaces.assert_called_with(ANY)
         interfaces = [i["interface"] for i in device_info]
@@ -72,7 +72,7 @@
     def test_skip_alias(self, mock_get_active_interfaces):
         """Interface aliases are not reported by L{get_active_device_info}."""
         mock_get_active_interfaces.side_effect = lambda sock: (
-            list(get_active_interfaces(sock)) + ["eth0:foo"])
+            list(get_active_interfaces(sock)) + [b"eth0:foo"])
         device_info = get_active_device_info()
         interfaces = [i["interface"] for i in device_info]
         self.assertNotIn("eth0:foo", interfaces)
@@ -94,23 +94,25 @@
         # This is a fake response observed to return the same interface several
         # times (here, br1:priv)
         response = (
-            "lo\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02"
-            "\x00\x00\x00\x7f\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00"
-            "\x00\x00\x00\x00\x00\x00\x00eth1:pub\x00\x00\x00\x00\x00\x00\x00"
-            "\x00\x02\x00\x00\x00\xc8\xb4\xc4.\x00\x00\x00\x00\x00\x00\x00\x00"
-            "\x00\x00\x00\x00\x00\x00\x00\x00br1:metadata\x00\x00\x00\x00\x02"
-            "\x00\x00\x00\xa9\xfe\xa9\xfe\x00\x00\x00\x00\x00\x00\x00\x00\x00"
-            "\x00\x00\x00\x00\x00\x00\x00br1:0\x00\x00\x00\x00\x00\x00\x00\x00"
-            "\x00\x00\x00\x02\x00\x00\x00\xc9\x19\x1f\x1d\x00\x00\x00\x00\x00"
-            "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00br1\x00\x00\x00\x00"
-            "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\xc0\xa8d"
-            "\x1d\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
-            "\x00br1:priv\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\xac"
-            "\x13\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
-            "\x00\x00\x00br1:priv\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00"
-            "\x00\xac\x13\x02A")
+            b"lo\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02"
+            b"\x00\x00\x00\x7f\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+            b"\x00\x00\x00\x00\x00\x00\x00eth1:pub\x00\x00\x00\x00\x00\x00\x00"
+            b"\x00\x02\x00\x00\x00\xc8\xb4\xc4.\x00\x00\x00\x00\x00\x00\x00"
+            b"\x00"
+            b"\x00\x00\x00\x00\x00\x00\x00\x00br1:metadata\x00\x00\x00\x00\x02"
+            b"\x00\x00\x00\xa9\xfe\xa9\xfe\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+            b"\x00\x00\x00\x00\x00\x00\x00br1:0\x00\x00\x00\x00\x00\x00\x00"
+            b"\x00"
+            b"\x00\x00\x00\x02\x00\x00\x00\xc9\x19\x1f\x1d\x00\x00\x00\x00\x00"
+            b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00br1\x00\x00\x00\x00"
+            b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\xc0\xa8d"
+            b"\x1d\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+            b"\x00br1:priv\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\xac"
+            b"\x13\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+            b"\x00\x00\x00br1:priv\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00"
+            b"\x00\xac\x13\x02A")
 
-        fake_array = array.array("B", response + "\0" * 4855)
+        fake_array = array.array("B", response + b"\0" * 4855)
 
         with patch("array.array") as mock_array:
             mock_array.return_value = fake_array
@@ -126,18 +128,19 @@
         mock_unpack.assert_called_with("iL", ANY)
 
         self.assertEqual(
-            ["lo", "eth1:pub", "br1:metadata", "br1:0", "br1", "br1:priv"],
+            [b"lo", b"eth1:pub", b"br1:metadata",
+             b"br1:0", b"br1", b"br1:priv"],
             interfaces)
 
-    @patch("__builtin__.open")
-    def test_get_network_traffic(self, mock_open):
+    def test_get_network_traffic(self):
         """
         Network traffic is assessed via reading /proc/net/dev, verify
         the parsed output against a known sample.
         """
-        mock_open.return_value = StringIO(test_proc_net_dev_output)
-        traffic = get_network_traffic()
-        mock_open.assert_called_with("/proc/net/dev", "r")
+        m = mock_open(read_data=test_proc_net_dev_output)
+        with patch('landscape.lib.network.open', m):
+            traffic = get_network_traffic()
+        m.assert_called_with("/proc/net/dev", "r")
         self.assertEqual(traffic, test_proc_net_dev_parsed)
 
 
@@ -221,7 +224,7 @@
         # ioctl always succeeds
         mock_unpack.return_value = (100, False)
 
-        result = get_network_interface_speed(sock, "eth0")
+        result = get_network_interface_speed(sock, b"eth0")
 
         mock_ioctl.assert_called_with(ANY, ANY, ANY)
         mock_unpack.assert_called_with("12xHB28x", ANY)
@@ -240,7 +243,7 @@
         # ioctl always succeeds
         mock_unpack.return_value = (65535, False)
 
-        result = get_network_interface_speed(sock, "eth0")
+        result = get_network_interface_speed(sock, b"eth0")
 
         mock_ioctl.assert_called_with(ANY, ANY, ANY)
         mock_unpack.assert_called_with("12xHB28x", ANY)
@@ -263,7 +266,7 @@
         # ioctl always raises
         mock_ioctl.side_effect = theerror
 
-        result = get_network_interface_speed(sock, "eth0")
+        result = get_network_interface_speed(sock, b"eth0")
 
         mock_ioctl.assert_called_with(ANY, ANY, ANY)
 
@@ -285,7 +288,7 @@
         # ioctl always raises
         mock_ioctl.side_effect = theerror
 
-        result = get_network_interface_speed(sock, "eth0")
+        result = get_network_interface_speed(sock, b"eth0")
 
         mock_ioctl.assert_called_with(ANY, ANY, ANY)
 
@@ -306,4 +309,4 @@
         # ioctl always raises
         mock_ioctl.side_effect = theerror
 
-        self.assertRaises(IOError, get_network_interface_speed, sock, "eth0")
+        self.assertRaises(IOError, get_network_interface_speed, sock, b"eth0")

=== modified file 'landscape/lib/tests/test_process.py'
--- landscape/lib/tests/test_process.py	2017-03-09 10:13:30 +0000
+++ landscape/lib/tests/test_process.py	2017-03-13 13:20:43 +0000
@@ -25,7 +25,8 @@
         os.mkdir(process_dir)
 
         cmd_line = "/usr/bin/foo"
-        create_file(os.path.join(process_dir, "cmdline"), cmd_line)
+        create_file(
+            os.path.join(process_dir, "cmdline"), cmd_line, encoding="utf-8")
 
         status = "\n".join([
             "Name: foo",
@@ -34,11 +35,12 @@
             "Gid: 2000",
             "VmSize: 3000",
             "Ignored: value"])
-        create_file(os.path.join(process_dir, "status"), status)
+        create_file(
+            os.path.join(process_dir, "status"), status, encoding="utf-8")
 
         stat_array = [str(index) for index in range(44)]
         stat = " ".join(stat_array)
-        create_file(os.path.join(process_dir, "stat"), stat)
+        create_file(os.path.join(process_dir, "stat"), stat, encoding="utf-8")
 
     @mock.patch("landscape.lib.process.detect_jiffies", return_value=1)
     @mock.patch("os.listdir")

=== modified file 'landscape/lib/vm_info.py'
--- landscape/lib/vm_info.py	2016-09-23 15:43:36 +0000
+++ landscape/lib/vm_info.py	2017-03-13 13:20:43 +0000
@@ -34,7 +34,7 @@
     for filename in ("container_type", "systemd/container"):
         path = os.path.join(run_path, filename)
         if os.path.exists(path):
-            return read_file(path).strip()
+            return read_file(path, encoding="utf-8").strip()
     return ""
 
 
@@ -52,7 +52,7 @@
 
 def _get_vm_by_vendor(sys_vendor_path):
     """Return the VM type string (possibly empty) based on the vendor."""
-    vendor = read_file(sys_vendor_path).lower()
+    vendor = read_file(sys_vendor_path, encoding="utf-8").lower()
     # Use lower-key string for vendors, since we do case-insentive match.
     content_vendors_map = (
         ("bochs", "kvm"),
@@ -72,7 +72,8 @@
 def _get_vm_legacy(root_path):
     """Check if the host is virtualized looking at /proc/cpuinfo content."""
     try:
-        cpuinfo = read_file(os.path.join(root_path, "proc/cpuinfo"))
+        cpuinfo = read_file(
+            os.path.join(root_path, "proc/cpuinfo"), encoding="utf-8")
     except (IOError, OSError):
         return ""