Merge lp:~chris-gondolin/charms/precise/nrpe-external-master/trunk into lp:charms/nrpe-external-master

[Chris Stratford]

The charm currently assumes "unit-get private-address" returns an IP address. This isn't always the case. This change attempts to ensure that $IPADDRESS really is an IP address (specifically an IPv4 address), so that the Nagios host check uses that IP address and does not rely on the results of a DNS lookup (which can return multiple addresses)

[JuanJo Ciarlante (jjo)]

LGTM, please address this 1 ~nit, consider 1 suggestion:
1) please anchor the regex, to be: '^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'
2) if you want, you could do: host -4 -t a ${addr} | awk 'NR==1 { print $NF }'

review: Approve

[lp:~chris-gondolin/charms/precise/nrpe-external-master/trunk]

27. By Chris Stratford on 2014-02-07

[chriss] Add jjo's suggested get_ipaddress improvements

28. By Chris Stratford on 2014-02-07

[chriss] Another jjo tweak

=== modified file 'hooks/config-changed'
--- hooks/config-changed	2013-08-30 22:10:07 +0000
+++ hooks/config-changed	2014-02-07 11:31:06 +0000
@@ -1,6 +1,21 @@
 #!/bin/bash
 set -eux
 
+# Try to ensure we have an IP address, not a hostname
+function get_ipaddress {
+    local addr=${1:?}
+    echo $addr | egrep -q '^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'
+    if [ $? -ne 0 ]; then
+        # Could be a hostname
+        addr=$(host -4 -t a ${addr} | awk 'NR==1 { print $NF }')
+        if [ ${addr} = "3(NXDOMAIN)" ]; then
+            # Maybe not, return the original input just to be safe
+            addr=$1
+        fi
+    fi
+    echo ${addr}
+}
+
 #-----------------------------------------------------
 # nrpe.cfg and rsyncd.conf
 #-----------------------------------------------------
@@ -69,7 +84,7 @@
 fi
 export NAGIOS_HOSTNAME="$(config-get nagios_host_context)-${RELATION}"
 export NAGIOS_HOSTNAME=${NAGIOS_HOSTNAME//\//-}
-export IPADDRESS=$(unit-get private-address)
+export IPADDRESS=$(get_ipaddress $(unit-get private-address))
 export HOSTCHECK_INHERIT=$(config-get hostcheck_inherit)
 export HOSTGROUPS=$(config-get hostgroups)
 cheetah fill --env --oext compiled templates/host.cfg.tmpl