Wrap read calls to /sys/class/net/DEV/{carrier, dormant, operstate} in

try/except blocks because there are sometimes read errors on the files and this
should not cause a stacktrace

1 files changed, 25 insertions, 15 deletions

diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index 800ffe61..e5b45926 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -306,24 +306,34 @@ def find_fallback_network_device():
     connected = []
     possibly_connected = []
     for interface in potential_interfaces:
-        sysfs_carrier = os.path.join(SYS_CLASS_NET, interface, 'carrier')
-        carrier = int(util.load_file(sysfs_carrier).strip())
-        if carrier:
-            connected.append(interface)
-            continue
+        try:
+            sysfs_carrier = os.path.join(SYS_CLASS_NET, interface, 'carrier')
+            carrier = int(util.load_file(sysfs_carrier).strip())
+            if carrier:
+                connected.append(interface)
+                continue
+        except OSError:
+            pass
         # check if nic is dormant or down, as this may make a nick appear to
         # not have a carrier even though it could acquire one when brought
         # online by dhclient
-        sysfs_dormant = os.path.join(SYS_CLASS_NET, interface, 'dormant')
-        dormant = int(util.load_file(sysfs_dormant).strip())
-        if dormant:
-            possibly_connected.append(interface)
-            continue
-        sysfs_operstate = os.path.join(SYS_CLASS_NET, interface, 'operstate')
-        operstate = util.load_file(sysfs_operstate).strip()
-        if operstate in ['dormant', 'down', 'lowerlayerdown', 'unknown']:
-            possibly_connected.append(interface)
-            continue
+        try:
+            sysfs_dormant = os.path.join(SYS_CLASS_NET, interface, 'dormant')
+            dormant = int(util.load_file(sysfs_dormant).strip())
+            if dormant:
+                possibly_connected.append(interface)
+                continue
+        except OSError:
+            pass
+        try:
+            sysfs_operstate = os.path.join(SYS_CLASS_NET, interface,
+                                           'operstate')
+            operstate = util.load_file(sysfs_operstate).strip()
+            if operstate in ['dormant', 'down', 'lowerlayerdown', 'unknown']:
+                possibly_connected.append(interface)
+                continue
+        except OSError:
+            pass
 
     # don't bother with interfaces that might not be connected if there are
     # some that definitely are