Table of Contents
Background
Velocity Variables
Sample Payloads for HTTP Request Templates
Additional Resources
Background
If you create health rule policies that trigger HTTP request actions or email notifications, you can use templates to customize the HTTP request or email message and render specific values when the action is triggered. These templates have a set of predefined variables that are processed using Apache Velocity Engine v1.7.
- For HTTP request actions, templates describe the HTTP request. You can use variables that replace values in the URL path and payload when the HTTP request is sent.
- For emails, you can use a template with variables to replace values in the body of the message.
You can configure custom variables if you need something beyond the predefined ones. This article provides examples of how you can use different Apache Velocity Template variables in HTTP request action and email templates.
Velocity Variables
The table below describes widely used Velocity variables to help you become more familiar with Velocity when you are customizing templates. A variable consists of a leading “$” followed by an identifier. It should look like this: $foo
| Description |
Variable |
| A custom variable |
Usage: $foo |
| Set a variable |
#set ($message = "Hello") |
| If statement |
#if ($message == "Hello")
Message received and is "Hello"
#end
|
| Replace HTML tags |
#set( $sm = $sm.replace("<b>", "[") ) |
| Escape characters |
$esc.java(${latestEvent.summaryMessage}) |
| Get the first element from an Array/List |
${latestEvent.affectedEntities[0].name}
${latestEvent.affectedEntities[0].entityTypeDisplayName}
|
| Loop through an Array/List |
#foreach( ${entity} in ${latestEvent.affectedEntities} )${entity.name}#if( $foreach.hasNext ),#end#end |
| Split |
#set ($summary = ${latestEvent.summaryMessage})
#set ($job = $summary.split(" "))
summary: $summary
Job: $job[2]
Job2: $job.get(2) |
| Replace |
#set( $sm = $!{latestEvent.summaryMessage.replace('"',"*")} )
#set( $sm = $sm.replace("<b>", "[") )
#set( $sm = $sm.replace("</b>", "]") )
#set( $sm = $sm.replace("<br>", " ") ) |
Sample Payloads for HTTP Request Templates
This article includes a sample HTTP request template payload for Hipchat. To learn about converting event time formats, or creating SMS or Slack alerts, see the resources below.
Additional Resources
