illumos: manual page: smf

SMF_TEMPLATE(7) Standards, Environments, and Macros SMF_TEMPLATE(7)

NAME

smf_template - service management framework support for service metadata

DESCRIPTION

Templates are defined by service developers to describe metadata about a
service in general or individual configuration properties on a service,
including human-consumable descriptions as well as definitions of valid
configuration.

Administrators are provided access to templates through SMF commands that
describe configuration values and validate configuration against
templates.

Tool developers can use templates to provide more helpful user interfaces
for service configuration.

Template Data

Service metadata is defined in the template as part of the service
manifest.

Consuming Template Data

The svcs -lv and svccfg describe commands can be used to access metadata
about properties in a human-readable format.

svccfg(8)'s validate subcommand can be used to validate a service
instance or manifest against template data. A set of libscf(3LIB)
interfaces is available to access template data.

Template Definition

The sole interface to define templates is the service manifest.

Service authors should provide template metadata including common_names,
descriptions, choices and constraints for service-specific property
groups and properties which they introduce. At a minimum, service authors
must provide descriptions for property groups and properties in the C
locale. Service authors should not provide template metadata for
framework-delivered property groups such as methods and dependencies.

See the EXAMPLES section for an example of authoring a template
definition for a service.

Template Composition

All template interfaces search for template data about a property group
first on the instance, then on the service, then on the service's
restarter, and finally globally.

A property group template is defined by its author to apply to a specific
instance, to a service and all of its instances, to a restarter's
delegates, or globally. A typical service author defines the template on
an instance or on a service. A template defined on an instance is applied
to that instance only, and can override a template for that property
group defined on the service. A template defined on the service is
applied to all instances of that service.

Restarter authors can define templates in their manifest that apply to
any service which uses their restarter, which is also known as a
delegate. SMF framework authors have defined templates for property
groups with well-known meanings to the entire SMF framework in the
manifest for svc:/system/svc/global.

Templates defined globally or by the restarter and re-defined by the
service or instance are flagged as a validation error. Service authors
can avoid these errors by creating templates only for property groups
specific to their service and not consumed by the SMF framework.

Property group templates can also be wildcarded by name or type. Only the
most specific template definition applicable to a property group is
honored.

Template Details

Service and Instance Templates

The template element defines the start of a template block. All further
definitions below can be included in a template block. A template element
can be contained in either a service or instance element. If it is
contained in the service element, it applies to the service and all
instances of that service. If it is contained in the instance element, it
applies to only that instance of the service.

Whenever possible, we recommend defining the template data for the entire
service.

<service ... >
<template>
</template>
</service>

Service and Instance Common Names

The entire service or instance can define a common name to describe the
purpose of the service/instance.

<template>
<common_name>
<loctext xml:lang='C'>console login</loctext>
</common_name>
<template>

common_name is a free-form string, but is intended to be used as a label
in a GUI or CLI.

The following guidelines are recommended:

o Be brief. A word or two is usually most appropriate. Limit the
name to under 40 characters.

o Be clear. The service, property group, or property name might
not be helpful for humans, but common_name should help clarify
the purpose of the entity.

o No punctuation. common_name is not a sentence or a paragraph.
It should not contain clauses or phrases. Punctuation should
only be present to meet trademark requirements.

o Capital letters must be used only for acronyms or proper
names. For locales other than English, use appropriate
capitalization for a sentence fragment.

Service and Instance Descriptions

The description element contains a longer description of the property
group, suitable for a status line or a tool-tip:

<template>
<description>
<loctext xml:lang='C'>Provide the text login prompt on console.
</lcotext>
</description>
<template>

description Guidelines

o Use proper grammar. description is a sentence meant to be read
by humans.

o Be brief. A few sentences are usually most appropriate.

Documentation

Documentation for this service can be defined explicitly, so that when
the service is experiencing issues, or a consumer of the service wants
more information on it, they can find it easily.

Documentation can include man pages or references to stable URLs for
reference documentation.

<template>
<documentation>
<manpage title='ttymon' section='8' manpath='/usr/share/man' />
<doc_link name='docs.sun.com' uri='http://docs.sun.com' />
</documentation>
</template>

Property Groups

The pg_pattern element contains the definitions for a property group:

<template>
<pg_pattern name="pgname" type="pgtype" target="this" required="true">
</pg_pattern>
</template>

name is the property group's name, and type is the property group's type.

target specifies what the target of this definition is. "this" would
refer to the defining service or instance. "instance" can only be used in
a service's template block, and means the definition applies to all
instances of this service. "delegate" can only be used in a restarter's
template block, and applies to all instances that are delegated to that
restarter. "all", only usable by the master restarter, would refer to all
services on the system. The default value of target is "this".

required indicates whether this property group is required or not. The
default value of required is false. If required is true, both name and
type must be specified.

name and/or type can be omitted. If either of these attributes is omitted
it is treated as a wildcard. For instance, if the name attribute is
omitted from the pg_pattern definition, the pg_pattern is applied to all
property groups that have the specified type.

Property Group Names

The common_name element contains the localized, human-readable name for
the property group:

<pg_pattern ...>
<common_name>
<loctext xml:lang='C'>startt method</loctext>
</common_name>
</pg_pattern>

common_name is a free-form string, but is intended to be used as a label
in a GUI or CLI.

The following guidelines are recommended:

o Be brief. A word or two is usually most appropriate.

o Be clear. The service, property group, or property name might
not be helpful for humans, but common_name should help clarify
the purpose of the entity.

o No punctuation. common_name is not a sentence or a paragraph.
It should not contain clauses or phrases. Punctuation should
only be present to meet trademark requirements.

o Capital letters must be used only for acronyms or proper
names. For locales other than English, use appropriate
capitalization for a sentence fragment.

Property Group Description

The description element contains a longer description of the property
group, suitable for a status line or a tool-tip:

<pg_pattern ...>
<description>
<loctext xml:lang='C'>A required method which starts the service.
</loctext>
</description>
</pg_pattern>

description Guidelines

o Use proper grammar. description is a sentence meant to be read
by humans.

o Be brief. A few sentences are usually most appropriate.

Properties

The prop_pattern element contains the definitions for a specific
property:

<pg_pattern ...>
<prop_pattern name="propname" type="proptype" required="true">
</prop_pattern>
</pg_pattern>

name is the property's name, and type is the property's type.

required indicates whether this property is required. The default value
of required is false.

name is always required. type is optional only if required is false.

Property Names

The common_name element contains the localized, human-readable name for
the property:

common_name is a free-form string field, but is intended to be used as a
label in a GUI or CLI.

<prop_pattern ...>
<common_name>
<loctext xml:lang='C'>retry interval</loctext>
</common_name>
</prop_pattern>

The following guidelines are recommended:

o Be brief. A word or two is usually most appropriate.

o Be clear. The service, property group, or property name might
not be helpful for humans, but common_name should help clarify
the purpose of the entity.

o No punctuation. common_name is not a sentence or a paragraph.
It should not contain clauses or phrases. Punctuation should
only be present to meet trademark requirements.

o Capital letters must be used only for acronyms or proper
names. For locales other than English, use appropriate
capitalization for a sentence fragment.

Property units

The units element contains the localized, human-readable units for a
numerical property:

<prop_pattern ...>
<units>
<loctext xml:lang='C'>seconds</loctext>
</units>
</prop_pattern>

units Guidelines

The following guidelines are recommended:

o Be brief. Strive to use only a single word or label. The
plural form is usually most appropriate.

o No punctuation. units is not a sentence or a paragraph. It
should not contain clauses or phrases. Punctuation should only
be present to meet trademark requirements.

Property description

The description element contains a longer description of the property,
suitable for a status line or a tool-tip:

<prop_pattern ...>
<description> <loctext xml:lang='C'>
The number of seconds to wait before retry.
</loctext> </description>
</prop_pattern>

description Guidelines

o Use proper grammar. description is a sentence meant to be read
by humans.

o Be brief. A few sentences are usually most appropriate.

Property visibility

The visibility element specifies whether simplified views in higher level
software might want to display this property.

<prop_pattern ...>
<visibility value="hidden | readonly | readwrite"/>
</prop_pattern>

Some properties are internal implementation details and should not be
presented as a configuration setting. Others might merely be read-only.
This property is used to specify these restrictions. A value of hidden
indicates that the property shouldn't be displayed, readonly means that
the property isn't intended to be modified, and readwrite indicates the
property is modifiable.

This is not a security mechanism, it is solely intended to help prevent
the user from shooting himself in the foot, and to remove unnecessary
clutter from CLI output or a GUI display. Hidden properties is visible in
full-disclosure modes of many commands and UIs.

Property format

The cardinality and internal_separators elements constrain the structure
of a property:

<prop_pattern ...>
<cardinality min="1" max="1"/>
<internal_separators>,<internal_separators>
</prop_pattern>

cardinality indicates the acceptable number of property values. min is
the minimum number, and max is the maximum number. Both are optional. If
neither is specified, <cardinality/> is the same as the default, zero or
more values.

internal_separators specify the separator characters used for those
property values into which multiple real values are packed.

Value constraints

The constraints element specifies what values are acceptable for a
property:

<prop_pattern ...>
<constraints>
<value name="blue" />
<range min="1" max="7"/>
<include_values type="values"/>
</constraints>
</prop_pattern>

The value element includes a possible property value. range includes an
integer range.

value and range can be used in any combination, as restricting their use
would prohibit many valid descriptions. If no value constraints are
specified, the property can take on any value.

include_values includes all values specified by the values block (see
Value Descriptions section).

Value choices

The choices block indicates which values a UI should offer the user:

<prop_pattern ...>
<choices>
<range min="1" max="3"/>
<value name="vt100" />
<value name="xterm" />
<include_values type="constraints"/>
<include_values type="values"/>
</choices>
</prop_pattern>

range and value include ranges and individual values like they do for
constraints.

include_values includes all values specified by either the constraints
block or the values block (see next section).

Value Descriptions

Like property names, the values a property can take on can also have
inscrutable representations. The values element contains localized,
human-readable descriptions for specific property values:

<prop_pattern>
<values>
<value name="blue">
<common_name>
<loctext xml:lang='C'>blueloctext xml:lang='C'>blue>
</common_name>
<description>
<loctext xml:lang='C>
The color between green and indigo.
</loctext>
</description>
</value>
</values>
</prop_pattern>

common_name is a free-form string field, but is intended to be used as a
label in a GUI or CLI.

The following guidelines are recommended:

o Be brief. A word or two is usually most appropriate.

o Be clear. The service, property group, or property name might
not be helpful for humans, but common_name should help clarify
the purpose of the entity.

o No punctuation. common_name is not a sentence or a paragraph.
It should not contain clauses or phrases. Punctuation should
only be present to meet trademark requirements.

o Capital letters must be used only for acronyms or proper
names. For locales other than English, use appropriate
capitalization for a sentence fragment.

description Guidelines

o Use proper grammar. description is a sentence meant to be read
by humans.

o Be brief. A few sentences are usually most appropriate.

EXAMPLES

Assuming a basic service which wants to define basic templates data
looks like this:

<?xml version="1.0"?
<!DOCTYPE service_bundle SYSTEM "/usr/share/lib/xml/dtd/service_bundle.dtd.1">
<service_bundle type='manifest' name='FOOfoo:foo'>
<service name='system/foo' type='service' version='1'>
<dependency>
name='multi-user'
type='service'
grouping='require_all'
restart_on='none'
<service_fmri value='svc:/milestone/multi-user' />
</dependency>
<exec_method
type='method'
name='start'
exec='/opt/foo/food'
timeout_seconds='60'>
</exec_method>
<exec_method
type='method'
name='stop'
exec=':kill'
timeout_seconds='60'>
</exec_method>
<property_group name='config' type='application'>
<propval name='local_only' type='boolean' value='false' />
<propval name='config_file' type='astring'
value='/opt/foo/foo.conf' />
<property name='modules' type='astring'>
<astring_list>
<value_node value='bar'/>
<value_node value='baz'/>
</astring_list>
</property>
</property_group>

<instance name='default' enabled='false' />
</service_bundle>
</service>

That service could define some basic templates data to help an
administrator using this service inside of the <service> tags. The most
helpful things are to document the purpose of the service itself and
the service-specific configuration.

<template>
<common_name> <loctext xml:lang='C'>
all-purpose demonstration
</loctext> /common_name>
<documentation>
<manpage title='food' section='8'
manpath='/opt/foo/man' />
</documentation>

<pg_pattern name='config' type='application' target='this'
required='true'>
<description> <loctext xml:lang='C'>
Basic configuration for foo.
</loctext> </description>
<prop_pattern name='local_only' type='boolean'
required='false'>
<description> <loctext xml:lang='C'>
Only listen to local connection requests.
</loctext> </description>
</prop_pattern>
<prop_pattern name='config_file' type='astring'
required='true'>
<cardinality min='1' max='1'/>
<description> <loctext xml:lang='C'>
Configuration file for foo.
</loctext> </description>
</prop_pattern>
<prop_pattern name='modules' type='astring'
required='false'>
<description> <loctext xml:lang='C'>
Plugin modules for foo.
</loctext> /description>
<values>
<value name='bar'>
<description> <loctext xml:lang='C'>
Allow foo to access the bar.
</loctext> </description>
</value>
<value name='baz'>
<description> <loctext xml:lang='C'>
Allow foo to access baz functions.
</loctext> </description>
</value>
<value name='qux'>
<description> <loctext xml:lang='C'>
Allow foo to access qux functions.
</loctext> </description>
</value>
</values>
<choices>
<include_values type='values'/>
</choices>
<prop_pattern>
</pg_pattern>
</template>

FILES

/usr/share/lib/xml/dtd/service_bundle.dtd.1