try to capture validation output and print out in case of failure to …

…validate

lib/service_config.cf

@@ -21,9 +21,11 @@ bundle agent service_config(service_name,config_template_path,config_final_path,
 
 bundle agent validate_config_and_restart_service(staged_config,validate_config_command,config_final_path,service_name)
 {
+  vars:
+    "validation_output" string => "$(staged_config)-validation.log";
   classes:
 
-    "config_validated"    expression => returnszero("$(validate_config_command) $(staged_config)", "useshell");
+    "config_validated"    expression => returnszero("$(validate_config_command) $(staged_config) 2>&1 >$(validation_output)", "useshell");
     "config_final_exists" expression => fileexists("$(config_final_path)");
     "staged_config_newer" expression => isnewerthan("$(staged_config)", "$(config_final_path)");
 
@@ -58,4 +60,5 @@ bundle agent validate_config_and_restart_service(staged_config,validate_config_c
       "$(staged_config) validates"                          if => "config_validated";
       "$(config_final_path) exists"                         if => "config_final_exists";
       "$(staged_config) is newer than $(config_final_path)" if => "staged_config_newer";
+      "validation output ${with}" with => readfile("${validation_output}");
 }