add check script - initial version with nslookup check

check.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# check whether all configured sources are resolvable via dns
+
+for file in $(ls sources)
+do
+    # echo ${file}
+    for source in $(cat sources/${file} | tr '\n' ' ' | sed 's/\/\*[^\*]*\*\///g' | jq -r '.. | objects | select(.stream) | .stream' | sed 's/tcp:\/\///' | sed 's/\:[0-9]*$//g')
+    do
+        
+        nslookup ${source} > /dev/null
+        if [ $? -gt 0 ]
+        then
+            echo ${source}
+            echo "fail"
+        fi
+    done
+done