Host inventory overview using Ansible’s Facts

Wednesday, January 21st, 2015

UPDATE: I’ve written a fancier version of the above script as a separate project called ansible-cmdb. It uses templates and can generate a feature-laden HTML version and text versions. It also lets you extend the information from your hosts very easily; even adding completely new hosts. Packages are available for Debian, Redhat and other operating systems.

Ansible is a multiplexing configuration orchestrator. It allows you to run commands and configure servers from a central system. For example, to run the uname -a command on servers in the group “intranet”:

[fboender@jib]~/Projects/ansible$ ansible -m shell -a "uname -a" intranet
host001.example.com | success | rc=0 >>
Linux host001.example.com 2.6.32-45-server #102-Ubuntu SMP Wed Jan 2 22:53:00 UTC 2013 x86_64 GNU/Linux

host004.example.com | success | rc=0 >>
Linux vps004c.example.com 2.6.32-55-server #117-Ubuntu SMP Tue Dec 3 17:45:11 UTC 2013 x86_64 GNU/Linux

Ansible can also gather system information using the ‘setup’ module. It returns the information as a JSON structure:

[fboender@jib]~/Projects/ansible$ ansible -m setup intranet
host001.example.com | success >> {
    "ansible_facts": {
        "ansible_all_ipv4_addresses": [
            "182.78.44.33", 
            "10.0.0.1"
        ], 
        "ansible_architecture": "x86_64", 
        "ansible_bios_date": "NA", 
        "ansible_bios_version": "NA", 
        ... etc

We can use this to display a short tabulated overview of important system information such as the FQDN, configured IPs, Disk and memory information. I wrote a quick script to do this. The result looks like this:

[fboender@jib]~/Projects/ansible$ ./hostinfo intranet
Name                     FQDN                     Datetime                    OS            Arch    Mem              Disk                 Diskfree          IPs
-----------------------  -----------------------  --------------------------  ------------  ------  ---------------  -------------------  ----------------  -------------------------------------------------------------------------
host001                  host001.example.com      2015-01-20 14:37 CET +0100  Ubuntu 12.04  x86_64  4g (free 0.16g)  80g                  40g               182.78.44.33, 10.0.0.1
host002                  host002.example.com      2015-01-20 14:37 CET +0100  Ubuntu 14.04  x86_64  2g (free 1.21g)  40g                  18g               182.78.44.34, 10.0.0.2
xxxxxx.xxxxxx.xx         xxxxxxx.example.com      2015-01-20 13:37 CET +0000  Ubuntu 10.04  x86_64  2g (free 0.04g)  241g                 20g               192.168.0.2, 10.000.0.4
xxxx.xxxxxx.xxx          xxxx.otherdom.com        2015-01-20 14:37 CET +0100  Ubuntu 13.04  x86_64  8g (free 0.14g)  292g, 1877g, 1877g   237g, 583g, 785g  192.168.1.9, 192.168.1.10, 10.0.0.6
xxxxxxxx.xxxxxx.xx       xxxx.otherdom.com        2015-01-20 14:36 CET +0100  Ubuntu 14.04  i386    6g (free 0.25g)  1860g, 1877g, 1877g  960g, 292g, 360g  10.0.0.5, 10.0.0.14, 192.168.1.12
xxxxx.xxxxx.xxx          test.otherdom.com        2015-01-20 14:37 CET +0100  Ubuntu 9.10   x86_64  2g (free 0.28g)  40g                  16g               10.0.0.15, 10.0.0.9

The script:

#!/usr/bin/python
# MIT license

import os
import sys
import shutil
import json
import tabulate
import pprint

host = sys.argv[1]
tmp_dir = 'tmp_fact_col'

try:
    shutil.rmtree(tmp_dir)
except OSError:
    pass
os.mkdir(tmp_dir)
cmd = "ansible -t {} -m setup {} >/dev/null".format(tmp_dir, host)
os.system(cmd)

headers = [
    'Name', 'FQDN', 'Datetime', 'OS', 'Arch', 'Mem', 'Disk', 'Diskfree', 'IPs',
]
d = []

for fname in os.listdir(tmp_dir):
    path = os.path.join(tmp_dir, fname)
    j = json.load(file(path, 'r'))
    if 'failed' in j:
        continue
    d.append(
        (
            fname,
            j['ansible_facts']['ansible_fqdn'],
            "%s %s:%s %s %s" % (
                j['ansible_facts']['ansible_date_time']['date'],
                j['ansible_facts']['ansible_date_time']['hour'],
                j['ansible_facts']['ansible_date_time']['minute'],
                j['ansible_facts']['ansible_date_time']['tz'],
                j['ansible_facts']['ansible_date_time']['tz_offset'],
            ),
            "%s %s" % (
                j['ansible_facts']['ansible_distribution'],
                j['ansible_facts']['ansible_distribution_version'],
            ),
            j['ansible_facts']['ansible_architecture'],
            '%0.fg (free %0.2fg)' % (
                (j['ansible_facts']['ansible_memtotal_mb'] / 1000.0),
                (j['ansible_facts']['ansible_memfree_mb'] / 1000.0)
                ),
            ', '.join([str(i['size_total']/1048576000) + 'g' for i in j['ansible_facts']['ansible_mounts']]),
            ', '.join([str(i['size_available']/1048576000) + 'g' for i in j['ansible_facts']['ansible_mounts']]),
            ', '.join(j['ansible_facts']['ansible_all_ipv4_addresses']),
        )
    )
    os.unlink(path)
shutil.rmtree(tmp_dir)
print tabulate.tabulate(d, headers=headers)

The script requires the Tabulator python library. Put the script in the directory containing your ansible hosts file, and run it.

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Host inventory overview using Ansible’s Facts