[BUG] Need to check if 'ifconfig' is available or replace with 'ip add show'

[juhlee-microsoft]

Describe the bug
'ifconfig' got deprecated and soon we won't see it in many distro. I still see below error message in today's SLES 15. Can you check if waagent can substitutes 'ip address show' when no ifconfig command available in the system?

Error in waagent.log : 2019/11/18 19:58:00.744410 ERROR Daemon Command: [ifconfig -a], return code: [127], result: [/bin/sh: ifconfig: command not found]

Note: Please add some context which would help us understand the problem better

1. Provision a new SLES 15
2. Check the waagent log

Distro and WALinuxAgent details (please complete the following information):

• Distro and Version: SLES 15 (4.12.14-5.30-azure)
• WALinuxAgent version: WALinuxAgent-2.2.36 running on sles 15
  Python: 3.6.8
  Goal state agent: 2.2.36

Additional context
NA

[narrieta]

@juhlee-microsoft - thanks for reporting this, could you attach the entire waagent.log?

[juhlee-microsoft]

waagent.log

[narrieta]

@juhlee-microsoft Thanks. We'll follow up.

[narrieta]

@longlimsft - could you take a look at this issue? we are using ifconfig during RDMA provisioning.

[juhlee-microsoft]

waagent 2.2.36 still shows below error and failed to initialize ib0 device interface. This blocks the SLES 15 RDMA tests.

2020/01/08 19:47:49.736059 INFO Daemon RDMA: waiting for any Infiniband device at directory=/sys/class/infiniband timeout=120s
2020/01/08 19:47:49.736712 INFO Daemon RDMA: device found in /sys/class/infiniband
2020/01/08 19:47:49.737348 INFO Daemon Wait for ib0 become available
2020/01/08 19:47:49.739908 ERROR Daemon Command: [ifconfig -a], return code: [127], result: [/bin/sh: ifconfig: command not found
]
2020/01/08 19:47:49.740684 ERROR Daemon RDMA: device processing failed: Failed to list network interfaces
2020/01/08 19:47:49.741306 INFO Daemon RDMA: completed device processing.
2020/01/08 19:47:49.741960 INFO Daemon RDMA: device is set up

[longlimsft]

@juhlee-microsoft , can you install ifconfig on sles15 to see if it fixes your problem:

apt install net-tools-deprecated

[juhlee-microsoft]

https://bugzilla.suse.com/show_bug.cgi?id=1160636

[jpbuecken]

@juhlee-microsoft , can you install ifconfig on sles15 to see if it fixes your problem:

apt install net-tools-deprecated

This is not a good advice: net-tools with ifconfig are only available in the legacy module of SLES15. The legacy module has shorter support lifecycle than the SLES15 itself.
So you may get a enterprise system with unsupported software.

Better fix

WALinuxAgent/bin/waagent2.0

Line 665 in 11d0881

ret, output = RunGetOutput("ifconfig -a")

and you may allow arbitary network interface names instead of hardcoded eth at that function.

See #1877 (comment) as well.

[alv000h]

@juhlee-microsoft @jpbuecken
It is better no user binaries, using /proc /sys is a better aproach...
Example to determine iface names on a machine:

Command:
$ ip r |grep link
10.100.100.0/23 dev nic0 proto kernel scope link src 10.100.100.25
10.255.255.0/21 dev nic1 proto kernel scope link src 10.255.255.33
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1
10.8.1.0/24 dev tap0 proto kernel scope link src 10.8.1.10

synonym from /proc (i have edited nicX destination, but tap0 and docker is OK, it must match with link src 10.X.X.X of above but with octets reversed):
$ cat /proc/net/route | awk '$3 == "00000000" { print $0}'
Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT
tap0 0001080A 00000000 0001 0 0 0 00FFFFFF 0 0 0
nic1 00000000 00000000 0001 0 0 0 00FFFFFF 0 0 0
nic0 00000000 00000000 0001 0 0 0 00FFFFFF 0 0 0
docker0 000011AC 00000000 0001 0 0 0 0000FFFF 0 0 0

[alv000h]

Addtional ideas:

$ ls -1 /sys/class/net
docker0
eth0
eth1
lo
tap0
tap1
tap2
tap3

$ cat /sys/class/net/eth0/address
00:00:AA:AA:AA:c3