update icinga2 example

docs/30_Examples.md

@@ -65,7 +65,7 @@ url_effective:http://www.iml.unibe.ch/
 
 ```
 
-# Icinga API
+# Icinga2 API
 
 In that example we have a config for an api access with url, user and password.
 The docs url is not required for functionality. It will be shown on errors.
@@ -80,7 +80,8 @@ RestApiPassword="password-of-Icinga-Api-User"
 RestApiDocs="https://icinga.com/docs/icinga2/latest/doc/12-icinga2-api/"
 ```
 
-And now let's access the Icinga API...
+And now let's access the Icinga API and try to find out if the current host
+is available in Icinga2. Therefor we make a GET request to `[API url]/objects/hosts/[my hostname]`.
 
 ```sh
 myHost=( hostname -f )
@@ -95,13 +96,13 @@ http.setDocs     "${RestApiDocs}"
 #     Because we set a base url we can operate with the part behind it
 http.makeRequest GET "objects/hosts/${myHost}"
 
-# --- show a result
+# --- show http response body (some JSON)
 http.getResponse
 
 # set return code of GET action ... $? is 0 on success (2xx status code)
 http.isOk >/dev/null
 if [ $? -ne 0 ]; then
-    if [ "`http.getStatuscode`" = "000" ]; then
+    if [ "$( http.getStatuscode )" = "000" ]; then
         echo "ERROR: Unable to reach the Icinga node."
         exit 1
     fi