Task Transforms
Note
These transforms are currently duplicated by standalone Taskgraph and will likely be refactored / removed at a later date.
Every kind needs to create tasks, and all of those tasks have some things in common. They all run on one of a small set of worker implementations, each with their own idiosyncrasies. And they all report to TreeHerder in a similar way.
The transforms in taskcluster/gecko_taskgraph/transforms/task.py implement
this common functionality. They expect a “task description”, and produce a
task definition. The schema for a task description is defined at the top of
task.py, with copious comments. Go forth and read it now!
In general, the task-description transforms handle functionality that is common to all Gecko tasks. While the schema is the definitive reference, the functionality includes:
TreeHerder metadata
Build index routes
Information about the projects on which this task should run
Optimizations
Defaults for
expires-afterand anddeadline-after, based on projectWorker configuration
The parts of the task description that are specific to a worker implementation
are isolated in a task_description['worker'] object which has an
implementation property naming the worker implementation. Each worker
implementation has its own section of the schema describing the fields it
expects. Thus the transforms that produce a task description must be aware of
the worker implementation to be used, but need not be aware of the details of
its payload format.
The task.py file also contains a dictionary mapping treeherder groups to
group names using an internal list of group names. Feel free to add additional
groups to this list as necessary.