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Templates

Templates can be assigned to a single or a group of rules and can contain any kind of text. There is also a default template which is used for any rule that isn't associated with a template. This template can be found under Alert Templates page and can be edited. It also has an option revert it back to its default content.

The template-parser understands if and foreach controls and replaces certain placeholders with information gathered about the alert.

Syntax

Controls:

  • if-else (Else can be omitted): {if %placeholder == value}Some Text{else}Other Text{/if}
  • foreach-loop: {foreach %faults}Key: %key<br/>Value: %value{/foreach}

Placeholders:

Placeholders are special variables that if used within the template will be replaced with the relevant data, I.e:

The device %hostname has been up for %uptime seconds would result in the following The device localhost has been up for 30344 seconds.

  • Device ID: %device_id
  • Hostname of the Device: %hostname
  • sysName of the Device: %sysName
  • sysDescr of the Device: %sysDescr
  • hardware of the Device: %hardware
  • Software version of the Device: %version
  • location of the Device: %location
  • uptime of the Device (in seconds): %uptime
  • short uptime of the Device (28d 22h 30m 7s): %uptime_short
  • long uptime of the Device (28 days, 22h 30m 7s): %uptime_long
  • description (purpose db field) of the Device: %description
  • notes of the Device: %notes
  • notes of the alert: %alert_notes
  • ping timestamp (if icmp enabled): %ping_timestamp
  • ping loss (if icmp enabled): %ping_loss
  • ping min (if icmp enabled): %ping_min
  • ping max (if icmp enabled): %ping_max
  • ping avg (if icmp enabled): %ping_avg
  • Title for the Alert: %title
  • Time Elapsed, Only available on recovery (%state == 0): %elapsed
  • Alert-ID: %id
  • Unique-ID: %uid
  • Faults, Only available on alert (%state != 0), must be iterated in a foreach ({foreach %faults}). Holds all available information about the Fault, accessible in the format %value.Column, for example: %value.ifDescr. Special field %value.string has most Identification-information (IDs, Names, Descrs) as single string, this is the equivalent of the default used.
  • State: %state
  • Severity: %severity
  • Rule: %rule
  • Rule-Name: %name
  • Timestamp: %timestamp

  • Transport name: %transport

  • Contacts, must be iterated in a foreach, %key holds email and %value holds name: %contacts

Placeholders can be used within the subjects for templates as well although %faults is most likely going to be worthless.

NOTE: Placeholder names which are contained within another need to be ordered correctly. As an example:

Limit: %value.sensor_limit / %value.sensor_limit_low

Should be done as:

Limit: %value.sensor_limit_low / %value.sensor_limit

The Default Template is a 'one-size-fit-all'. We highly recommend defining your own templates for your rules to include more specific information.

Examples

Default Template:

%title
Severity: %severity
{if %state == 0}Time elapsed: %elapsed{/if}
Timestamp: %timestamp
Unique-ID: %uid
Rule: {if %name}%name{else}%rule{/if}
{if %faults}Faults:
{foreach %faults}  #%key: %value.string{/foreach}{/if}
Alert sent to: {foreach %contacts}%value <%key> {/foreach}

Ports Utilization Template:

%title
Device Name: %hostname
Severity: %severity
{if %state == 0}Time elapsed: %elapsed{/if}
Timestamp: %timestamp
Rule: {if %name}%name{else}%rule{/if}
{foreach %faults}
Physical Interface: %value.ifDescr
Interface Description: %value.ifAlias
Interface Speed: {calc (%value.ifSpeed/1000000000)} Gbs
Inbound Utilization: {calc ((%value.ifInOctets_rate*8)/%value.ifSpeed)*100}%
Outbound Utilization: {calc ((%value.ifOutOctets_rate*8)/%value.ifSpeed)*100}%
{/foreach}

Storage:

%title

Device Name: %hostname
Severity: %severity
Uptime: %uptime_short
{if %state == 0}Time elapsed: %elapsed{/if}
Timestamp: %timestamp
Location: %location
Description: %description
Features: %features
Purpose: %purpose
Notes: %notes

Server: %sysName {foreach %faults}Mount Point: %value.storage_descr Percent Utilized: %value.storage_perc{/foreach}

Temperature Sensors:

%title

Device Name: %hostname
Severity: %severity
Timestamp: %timestamp
Uptime: %uptime_short
{if %state == 0}Time elapsed: %elapsed{/if}
Location: %location
Description: %description
Features: %features
Purpose: %purpose
Notes: %notes

Rule: {if %name}%name{else}%rule{/if}
{if %faults}Faults:
{foreach %faults}
#%key: Temperature: %value.sensor_current°C
** {calc(%value.sensor_current-%value.sensor_limit)}°C over limit
Previous Measurement: %value.sensor_prev°C
High Temperature Limit: %value.sensor_limit°C
{/foreach}
{/if}

Value Sensors:

%title

Device Name: %hostname
Severity: %severity
Timestamp: %timestamp
Uptime: %uptime_short
{if %state == 0}Time elapsed: %elapsed{/if}
Location: %location
Description: %description
Features: %features
Purpose: %purpose
Notes: %notes

Rule: {if %name}%name{else}%rule{/if}
{if %faults}Faults:
{foreach %faults}
#%key: Sensor%value.sensor_current
** {calc(%value.sensor_current-%value.sensor_limit)}over limit
Previous Measurement: %value.sensor_prev
Limit: %value.sensor_limit
{/foreach}
{/if}

Memory Alert:

%title

Device Name: %hostname
Severity: %severity
Uptime: %uptime_short
{if %state == 0}Time elapsed: %elapsed{/if}
Timestamp: %timestamp
Location: %location
Description: %description
Notes: %notes

Server: %hostname {foreach %faults}
Memory Description: %value.mempool_descr
Percent Utilized: %value.mempool_perc{/foreach}

Conditional formatting example, will display a link to the host in email or just the hostname in any other transport:

{if %transport == mail}<a href="https://my.librenms.install/device/device=%hostname/">%hostname</a>
{else}
%hostname
{/if}

Note the use of double-quotes. Single quotes (') in templates will be escaped (replaced with \') in the output and should therefore be avoided.

Examples HTML

Note: To use HTML emails you must set HTML email to Yes in the WebUI under Global Settings > Alerting Settings > Email transport > Use HTML emails

Note: To include Graphs you must enable unauthorized graphs in config.php. Allow_unauth_graphs_cidr is optional, but more secure.

$config['allow_unauth_graphs_cidr'] = array('127.0.0.1/32');
$config['allow_unauth_graphs'] = true;

Service Alert:

<div style="font-family:Helvetica;">
<h2>{if %state == 1}<span style="color:red;">%severity{/if}
{if %state == 2}<span style="color:goldenrod;">acknowledged{/if}</span>
{if %state == 3}<span style="color:green;">recovering{/if}</span>
{if %state == 0}<span style="color:green;">recovered{/if}</span>
</h2>
<b>Host:</b> %hostname<br>
<b>Duration:</b> %elapsed<br>
<br>

{if %faults}
{foreach %faults}<b>%value.service_desc - %value.service_type</b><br>
%value.service_message<br>
<br>
{/foreach}
{/if}
</div>

Processor Alert with Graph:

%title <br>
Severity: %severity  <br>
{if %state == 0}Time elapsed: %elapsed{/if}
Timestamp: %timestamp <br>
Alert-ID: %id <br>
Rule: {if %name}%name{else}%rule{/if} <br>
{if %faults}Faults:
{foreach %faults}
#%key: %value.string <br>
{/foreach}
{if %faults}<b>Faults:</b><br>
{foreach %faults}<img src="https://server/graph.php?device=%value.device_id&type=device_processor&width=459&height=213&lazy_w=552&from=end-72h%22/%3E<br>
https://server/graphs/id=%value.device_id/type=device_processor/<br>
{/foreach}
Template: CPU alert <br>
{/if}
{/if}

Included

We include a few templates for you to use, these are specific to the type of alert rules you are creating. For example if you create a rule that would alert on BGP sessions then you can assign the BGP template to this rule to provide more information.

The included templates apart from the default template are:

  • BGP Sessions
  • Ports
  • Temperature