collector crashed on non-English server environments

[zealot128]

Running latest stable releae on a Ubuntu 12.04 (German) server, crashes collector, due to decimal seperator:

Traceback (most recent call last):
  File "agent/agent.py", line 198, in <module>
    daemon.run()
  File "agent/agent.py", line 84, in run
    c.doChecks(True, systemStats, checksd)
  File "/profiles/swi/.datadog-agent/agent/checks/common.py", line 230, in doChecks
    cpuStats = sys_checks['cpu'].check(self.checksLogger, self.agentConfig)
  File "/profiles/swi/.datadog-agent/agent/checks/system/unix.py", line 590, in check
    cpu_usr = get_value(headers, data, "%usr")
  File "/profiles/swi/.datadog-agent/agent/checks/system/unix.py", line 554, in get_value
    return float(data[legend.index(name)])
ValueError: invalid literal for float(): 0,17

Traceback (most recent call last):
  File "agent/agent.py", line 198, in <module>
    daemon.run()
  File "agent/agent.py", line 84, in run
    c.doChecks(True, systemStats, checksd)
  File "/profiles/swi/.datadog-agent/agent/checks/common.py", line 230, in doChecks
    cpuStats = sys_checks['cpu'].check(self.checksLogger, self.agentConfig)
  File "/profiles/swi/.datadog-agent/agent/checks/system/unix.py", line 590, in check
    cpu_usr = get_value(headers, data, "%usr")
  File "/profiles/swi/.datadog-agent/agent/checks/system/unix.py", line 554, in get_value
    return float(data[legend.index(name)])
ValueError: invalid literal for float(): 0,21

Workaround:

export LC_ALL=en_US.UTF-8

(before was de_DE.UTF-8)

Output from mpstat 1 3 (which is run from unix.py:554)

$ mpstat 1 3
Linux 3.2.0-32-generic (hal)    21.11.2012      _x86_64_        (8 CPU)

23:58:14     CPU    %usr   %nice    %sys %iowait    %irq   %soft  %steal  %guest   %idle
23:58:15     all    0,25    0,00    0,62    0,00    0,00    0,12    0,00    0,00   99,00
23:58:16     all    0,25    0,00    0,25    0,00    0,00    0,00    0,00    0,00   99,50
23:58:17     all    0,13    0,00    0,25    0,00    0,00    0,00    0,00    0,00   99,62
Average:     all    0,21    0,00    0,38    0,00    0,00    0,04    0,00    0,00   99,37

[alq666]

We fixed this in the packaged versions (#80) but must have left it out from the source install.

[alq666]

#676 has a better fix, since LC_ALL overrides LANG and we were using LANG up until now.