Merge ~hloeung/influxdb-charm:master into influxdb-charm:master

[Haw Loeung]

Update nagios check to support authenticating

[Paul Gear (paulgear)]

LGTM

review: Approve

diff --git a/files/check_influxdb.py b/files/check_influxdb.py
index 5ab579b..7a09658 100755
--- a/files/check_influxdb.py
+++ b/files/check_influxdb.py
@@ -5,12 +5,25 @@
 # Description: Run influxdb 'show diagnostics' command to ensure influxdb is running and operational
 
 import json
+import os
 import subprocess
 import sys
 import traceback
 
+
+cmd = ['influx', '-execute', 'show diagnostics', '-format', 'json']
+
+authf = os.path.join(os.path.expanduser('~'), '.influx-auth')
+username = None
+password = None
+if os.path.exists(authf):
+    with open(authf, 'r') as f:
+        username, password = f.readline().split()
+if username and password:
+    cmd.extend(['-username', username, '-password', password])
+
 try:
-    output = subprocess.check_output(['influx', '-execute', 'show diagnostics', '-format', 'json'])
+    output = subprocess.check_output(cmd)
     j = json.loads(output.decode('utf-8'))
     for o in j['results'][0]['series']:
         if o['name'] == 'system' and o['columns'][-1] == 'uptime':