Source:Task Name Template – Backup: Difference between revisions

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The ''Rythm'' template engine has the following advantages:
The ''Rythm'' template engine has the following advantages:
*Flexibility in writing template side code as it uses Java like syntax and allows embedding Java code snippets inside the template source.
*Flexibility in writing template side code as it uses Java like syntax and allows embedding Java code snippets inside the template source.
•Easy to integrate into an existing Java application.
*Easy to integrate into an existing Java application.
•Supports template inheritance as well as macros.
*Supports template inheritance as well as macros.
•Handling of complex data types.
*Handling of complex data types.
 
For more details, see [http://rythmengine.org/ ''Rythm templates''].


===Mustache syntax===  
===Mustache syntax===  

Revision as of 14:20, 22 October 2020

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Docs latest icon.png Welcome to the latest SEP sesam documentation version 4.4.3 Beefalo V2. For previous documentation version(s), check documentation archive.


Overview

As of 4.4.3 Beefalo V2, SEP sesam supports a higher level of automation for performing administrative work by generating administrative objects, such as backup tasks, based on a given template.

Templates can be created to allow SEP sesam administrators to automatically create backup tasks by replacing specific information with variables, thus saving time and simplifying backup management. Templates can be configured in the SEP sesam GUI -> Configuration -> Defaults -> Extras -> Template, as described in GUI Configuration options: Extras.

Backup task name template usage

SEP sesam used the Mustache specification for a templating language to auto-generate the name of backup tasks while creating the task using the UI server’s REST API. Due to some limitations of the Mustache template, SEP sesam introduced a more flexible and powerful Rythm template engine.

The Rythm template engine has the following advantages:

  • Flexibility in writing template side code as it uses Java like syntax and allows embedding Java code snippets inside the template source.
  • Easy to integrate into an existing Java application.
  • Supports template inheritance as well as macros.
  • Handling of complex data types.

For more details, see Rythm templates.

Mustache syntax

Currently, SEP sesam auto-generates the name of the backup task by using the Mustache specification for a templating language. For example, if the name property of the backup task is set to backup_task_{{client}} and the client property of the backup task evaluates to snowfix, the UI server updates the name property of the backup task to backup_task_snowfix before committing this backup task to the database.

The syntax used by Mustache to denote a placeholder for named property is:

{{<property name>}}

Rythm syntax

The Rythm template engine uses a different syntax. The full Rythm template source for achieving the same result as in the example above is:

@args String client
backup_task_@(client)
Information sign.png Note
There are no pre-configured templates available for customization. Until you configure a template, SEP sesam uses the default auto-generated names for bakup tasks.

Using placeholders

The following table lists placeholders that can be used in the backup task name template.

Name Type Description
client string The name of the client associated with the backup task object.
source string The source property of the backup task object.
count string A number between 1 and 10000. Evaluates to the first number in this range leading to a unique task name.
count_optional string Equals the count token which is used when a task already exists.
task tasks The backup task object.
Note: This placeholder can only be used together with a native Rythm template.

Functions (Mustache syntax only)

The following transformation functions are supported when using the Mustache syntax.

Information sign.png Note
These functions cannot be combined when using Mustache. If more complex transformations are required, use the Rythm syntax.
Name Description
toLower Converts all characters in the placeholder value to lower case.
toUpper Converts all characters in the placeholder value to upper case.
dashPrefix Prepends a dash character (-) to the placeholder value, if the value is not blank.
dotPrefix Prepends a dot character (.) to the placeholder value, if the value is not blank.
underPrefix Prepends an underscore character (_) to the placeholder value, if the value is not blank.
substring (start,end) Evaluates to a string that is a substring of the string representation of the placeholder value. The character indices start with 0.
replace (target,replacement) Evaluates to a string where the target character sequence is replaced by the replacement character sequence.
trimUnderPrefix Removes any leading underscore character (_) from the placeholder value.
trimUnderTrailing Removes any trailing underscore character (_) from the placeholder value.

Examples

In our example, the following placeholder values are used:

Name Type Value
client string SnowFix
source string C:\work\test
count string 10
Mustache

Using the Mustache syntax, the templates will evaluate as follows.

Name Value
sep-task-{{client}} sep-task-SnowFix
sep-task-{{toLower client}} sep-task-snowfix
sep-task-{{toUpper client}} sep-task-SNOWFIX
sep-task-{{client}}-{{source}} sep-task-SnowFix_C_work_test
sep-task-{{client}}-{{substring(3,7) source}} sep-task-SnowFix-work
sep-task-{{client}}-{{replace("test","folder") source}} sep-task-SnowFix_C_work_folder
sep-task{{underPrefix count}} sep-task_10
sep-task{{dashPrefix count_optional}} sep-task (not exist)
sep-task-0 (already exists)
Rythm

Using the Rythm syntax, the templates will evaluate as follows.

Name Value
@args String client\ntasks_rythm_@(client) tasks_rythm_SnowFix
@args String client, String source\ntasks_rythm_@(client.toLowerCase())_@(source.substring(3,7).toUpperCase()) tasks_rythm_snowfix_WORK

Shortcuts for inner VMDto object

You can easily access all field names of the task attribute VMDto by using shortcuts. Each shortcut represents a field name of the VMDto object.

Valid VMDto shortcuts: name, isVCenter, path, datacenter, moref, powerState, ipAddress, hostName, macAddress, hostSystem, cluster, version, guestFullName, uuid, sesamClient, folder, vapp, taskGroupRef, hostVersion

Example:

add task "@args de.sep.sesam.model.dto.VMDto vmDto;@ deb_ (vmDto.getMoRef())" …

is the same as

add task "@args String moref;deb_@(moref)"…

Example with GetAttribute:

add taskgen "@args de.sep.sesam.model.dto.FileDto 
fileDto;@(fileDto.getAdditionalInformationAsMap().get(\"Status\"))"  "-c" "hypervdev" "-t" 
"Hyper-V" -s hyperV -f "c:\tmp\hyperv.txt" -G "hyperVGenGroup3
add taskgen "@args de.sep.sesam.model.Tasks task;qs-@(task.getClient().getShortName())- 
@(task.getShortType())_@(task.getSourceSegment(0))" -f d:\input.json -O remove_all -G vm-8

Special shortcuts for easy access (without rhythm keywords)

The Rythm syntax is not required when using special shortcuts in tags – curly braces, i.e., {{<shortcut>}}.

The name generation shortcuts

Shortcut Description
{{CLIENT_SHORT}} get client without domain
{{TASK_TYPE_SHORT}} get short name of task type
{{SOURCE_LAST_ITEM}} get last source segment separated by slash
{{SOURCE_ITEM[<pos>]}} get segment pos separated by slash (negative pos as pos from back)
{{<field>}} use the description block field (cli action dir last param).

Example:

{{uuid}}Status=Running,OwnerNode=HYPERVDEV,Clustered=No,uuid=2E4120B2-C0FC-4D99-8737-21EC5C9D7BC

Note: You can use all description fields (UUID, folder, Guest OS,...) from output of the list (-f -) for task name.

Examples

  • Backup task with type Hypervdev from input stream:
  • sm_cmd dir -F JSON client "/hypervdev.sep.de/Hyper-V:" | sm_cmd add taskgen "gen_{{TASK_TYPE_SHORT}}_{{SOURCE_ITEM[1]}}-{{SOURCE_ITEM[-1]}}-{{uuid}}" "-t" "Hyper-V" –c hypervdev.sep.de -f - -O remove_all -G hv-5
  • Backup task with type Hypervdev from file:
  • sm_cmd add taskgen "gen_{{TASK_TYPE_SHORT}}_{{SOURCE_ITEM[1]}}-{{SOURCE_ITEM[-1]}}-{{uuid}}" "-t" "Hyper-V" -c hypervdev.sep.de -f d:\hyperv.json -O remove_all -G hv-5
  • Backup task with type Path from file:
  • sm_cmd add taskgen "{{CLIENT_SHORT}}-{{TASK_TYPE_SHORT}}_{{SOURCE_LAST_ITEM}}" -G pathgroup -f c:\root\path.json –t “Path”


See also

GUI Configuration options: Extras