Manifest Entry Unit¶
A manifest entry unit describes a single entry in a manifest that describes the machine or device under test. The purpose of each entry is to define one specific fact. Plainbox uses such units to create a manifest that associates each entry with a value.
The values themselves can come from multiple sources, the simplest one is the test operator who can provide an answer. In more complex cases a specialized application might look up the type of the device using some identification method (such as DMI data) from a server, thus removing the extra interaction steps.
File format and location¶
Manifest entry units are regular plainbox units and are contained and shipped with plainbox providers. In other words, they are just the same as job and test plan units, for example.
Fields¶
Following fields may be used by a manifest entry unit.
id
:- (mandatory) - Unique identifier of the entry. This field is used to look up and store data so please keep it stable across the lifetime of your provider.
name
:(mandatory) - A human readable name of the entry. This should read as in a feature matrix of a device in a store (e.g., “802.11ac wireless capability”, or “Thunderbolt support”, “Number of hard drive bays”). This is not a sentence, don’t end it with a dot. Please capitalize the first letter. The name is used in various listings so it should be kept reasonably short.
The name is a translatable field so please prefix it with
_
as in_name: Example
.value-type
:- (mandatory) - Type of value for this entry. Currently two values are
allowed:
bool
for a yes/no value andnatural
for any natural number (negative numbers are rejected). value-units
:- (optional) - Units in which value is measured in. This is only used when
value-type
is equal tonatural
. For example a “Screen size” manifest entry could be measured in “inch” units. resource-key
:- (optional) - Name of the resource key used to store the manifest value when
representing the manifest as a resource record. This field defaults to the
so-called partial id which is just the
id:
field as spelled in the unit definition file (so without the name space of the provider) prompt
:- (optional) - Allows the manifest unit to customise the prompt presented
when collecting values from a user. When the
value-type
isbool
the default prompt is “Does this machine have this piece of hardware?”, when thevalue-type
isnatural
the default prompt is “Please enter the requested data”.
Example¶
This is an example manifest entry definition:
unit: manifest entry
id: has_thunderbolt
_name: Thunderbolt Support
value-type: bool
Naming Manifest Entries¶
To keep the code consistent there’s one naming scheme that should be followed.
Entries for boolean values must use the has_XXX
naming scheme. This will
allow us to avoid issues later on where multiple people develop manifest
entries and it’s all a bit weird what them mean has_thunderbolt
or
thunderbolt_supported
or tb
or whatever we come up with. It’s a
convention, please stick to it.
Using Manifest Entries in Jobs¶
Manifest data can be used to decide if a given test is applicable for a given
device under test or not. When used as a resource they behave in a standard
way, like all other resources. The only special thing is the unique name-space
of the resource job as it is provided by plainbox itself. The name of the
resource job is: com.canonical.plainbox
. In practice a simple job that
depends on data from the manifest can look like this:
unit: job
id: ...
plugin: ...
requires:
manifest.has_thunderbolt == 'True' and manifest.ns == 'com.canonical.checkbox'
imports: from com.canonical.plainbox import manifest
Note that the job uses the manifest
job from the
com.canonical.plainbox
name-space. It has to be imported using the
imports:
field as it is in a different name-space than the one the example
unit is defined in (which is arbitrary). Having that resource it can then check
for the has_thunderbolt
field manifest entry in the
com.canonical.checkbox
name-space. Note that the name-space of the
manifest
job is not related to the manifest.ns
value. Since any
provider can ship additional manifest entries and then all share the flat
name-space of resource attributes looking at the .ns
attribute is a way to
uniquely identify a given manifest entry.
Collecting Manifest Data¶
To interactively collect manifest data from a user please include this job
somewhere early in your test plan:
com.canonical.plainbox::collect-manifest
.
Supplying External Manifest¶
The manifest file is stored in
$HOME/.local/share/plainbox/machine-manifest.json
.
If the provisioning method ships a valid manifest file there it can be used for
fully automatic but manifest-based deployments.