add linux / cumulus support

[thomas-mangin]

This is a slightly modified version of what I used to be able to get IXLeeds Cumulus switches SNMP discovered. As I saw a feature request for generic Linux, I also added it, it was not tested but the regex works:

> snmpwalk -c <you are kinding ritght ?> -On -v 2c 127.0.0.1 .1.3.6.1.2.1.1.1.0
.1.3.6.1.2.1.1.1.0 = STRING: "Linux ixleeds1 3.11.0-23-generic #40-Ubuntu SMP Wed Jun 4 21:05:23 UTC 2014 x86_64"

>>> print re.compile('Linux ([^ ]+) ([^ ]+)-([^ ]+) #[^ ]+-([^ ]+) SMP ([^ ]+) ([^ ]+) ([^ ]+) ([^ ]+) ([^ ]+) ([^ ]+) (.*)').search('Linux ixleeds1 3.11.0-23-generic #40-Ubuntu SMP Wed Jun 4 21:05:23 UTC 2014 x86_64').groups()
('ixleeds1', '3.11.0-23', 'generic', 'Ubuntu', 'Wed', 'Jun', '4', '21:05:23', 'UTC', '2014', 'x86_64')

[dorkmatt]

For detecting @CumulusNetworks, any reason not use to use the well known sysObjectID? This has the Cumulus Networks well know registered enterprise OID.

# snmpwalk -v2c -c w00f 127.0.0.1 system.sysObjectID.0
SNMPv2-MIB::sysObjectID.0 = OID: SNMPv2-SMI::enterprises.40310

[thomas-mangin]

When adding the feature, I used the template for other vendors which have more than one line of product and for which the string can be used to identify the hardware used. This OID could be used but it would require two SNMP get as we would still need to gather the time for, so I see no reason to change it unless you are planning to change your kernel format string, as we rely on the "+" separator which is unique to Cumulus AFAIK.

[barryo]

@dorkmatt - no reason not to. In fact, the platform discovery documentation welcomes these ideas 😄

See c4bc88b which now allows for the use of $sysObjectID in platform discover (and it's already populated).

@thomas-mangin I suggest $sysObjectID is a better (and safer) way to determine Cumulus kit. I have no way of testing so I have not amended the code.

[thomas-mangin]

@barryo I agree it is a safer way ( the uname string are not really a defined API ). I can test the code.