[skip ci] Deprecation warning and error handling

Author: Chris Wiechmann

filebeat/scripts/custom-entrypoint.sh

@@ -3,11 +3,21 @@
 # This script adjusts the configured list of Logstash hosts
 # as is it required by Filebeat. 
 
+if [ -z "${LOGSTASH_HOSTS}" ];then
+        if [ -z "${LOGSTASH}" ]; then
+		echo "Parameter: LOGSTASH_HOSTS is missing";
+		exit 99;
+	else 
+                echo "Parameter LOGSTASH is deprecated. Please migrate your configuration to parameter: LOGSTASH_HOSTS";
+                LOGSTASH_HOSTS=${LOGSTASH}
+        fi
+fi
+
 hostsForFilebeat=`echo ${LOGSTASH_HOSTS} | awk '{split($0, va, /,/); vl=""; for (v in va) { if (vl =="" ) vl = sprintf("\"%s\"", va[v]); else vl = vl sprintf(",\"%s\"", va[v]); } printf("'[%s]'", vl) }'`
 
 echo "Adjusted given Logstash hosts: ${hostsForFilebeat} for Filebeat"
 
 export LOGSTASH_HOSTS=$hostsForFilebeat
 
 # Finally call the original Docker-Entrypoint
-/usr/local/bin/docker-entrypoint "$@"
+/usr/local/bin/docker-entrypoint "$@"