apache-frontend: monitor add apache configuration viewer

NOTE: If the configuration is wrong the output is null

software/apache-frontend/instance-apache-frontend.cfg

@@ -51,6 +51,7 @@ parts =
   monitor-current-log-access
   monitor-backup-log-access
   monitor-ats-cache-stats-wrapper
+  monitor-apache-configuration-verification
 
 extends = ${monitor-template:output}
 
@@ -618,3 +619,13 @@ rendered = $${trafficserver-configuration-directory:target}/cache-config.stats
 mode = 644
 context =
     raw content show:cache-stats
+
+# Display result of apache configuration check
+[monitor-apache-configuration-verification]
+< = jinja2-template-base
+template = ${template-wrapper:output}
+rendered = $${monitor-directory:monitoring-cgi}/front-httpd-configuration
+mode = 0700
+command = echo "<pre>$($${apache-configuration:frontend-configuration-verification})</pre>"
+extra-context =
+  key content :command