set max_retries to UINT32_MAX for asterisk registrations

After a brief internet outage, I noticed that asterisk had given up
trying to reconnect to my upstream SIP server (looks like the default
value of max_retries is 10).

Although the asterisk "registration" object was disconnected, the
"endpoint" object still reported being up, so the
check_asterisk_endpoints nagios plugin did not alert me to the problem.

This commit sets max_retries to UNIT32_MAX for asterisk registrations by
default. It also adds a new nagios plugin, check_asterisk_registrations.
Unfortunately, the ARI does not expose registrations via the REST API,
so I had to write a hacky bash script to parse the asterisk CLI output.

1 files changed, 40 insertions, 0 deletions

diff --git a/roles/nagios_client/files/usr/lib64/nagios/plugins/check_asterisk_registrations b/roles/nagios_client/files/usr/lib64/nagios/plugins/check_asterisk_registrations
new file mode 100644
index 0000000..132e4e3
--- /dev/null
+++ b/roles/nagios_client/files/usr/lib64/nagios/plugins/check_asterisk_registrations
@@ -0,0 +1,40 @@
+#!/bin/bash
+
+set -Eeu -o pipefail
+shopt -s lastpipe
+
+trap 'exit 3' ERR
+
+ok=()
+error=()
+
+sudo asterisk -rx 'pjsip show registrations' \
+  | sed '1,4d'                               \
+  | head -n2                                 \
+  | while read -r uri auth status
+do
+  msg="${auth} is ${status,,}"
+  if [ "$status" = Registered ]; then
+    ok+=("$msg")
+  else
+    err+=("$msg")
+  fi
+done
+
+if (( ${#error[@]} )); then
+  echo 'trunk is not registered!'
+  RC=2
+else
+  echo 'all trunks registered'
+  RC=0
+fi
+
+if (( ${#error[@]} )); then
+  printf 'CRIT: %s\n' "${error[@]}"
+fi
+
+if (( ${#ok[@]} )); then
+  printf 'OK: %s\n' "${ok[@]}"
+fi
+
+exit $RC