add simple monitoring for pagure's celery redis queue

Signed-off-by: Ricky Elrod <codeblock@fedoraproject.org>

roles/nagios_client/files/scripts/check_redis_queue.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+. /usr/lib64/nagios/plugins/utils.sh
+
+if [[ "$#" -ne 3 ]]; then
+  echo "Arguments: key warn crit"
+  exit $STATE_UNKNOWN
+fi
+
+tasks="$(redis-cli llen "$1" | awk '{print $1}')"
+
+check_range $tasks $2:$3
+status=$?
+
+if [[ "$status" == "$STATE_OK" ]]; then
+  echo "OK: $1 queue has $tasks tasks"
+elif [[ "$status" == "$STATE_WARNING" ]]; then
+  echo "WARNING: $1 queue has $tasks tasks"
+elif [[ "$status" == "$STATE_CRITICAL" ]]; then
+  echo "CRITICAL: $1 queue has $tasks tasks"
+fi
+
+exit $status