A number of mach subcommands are available aside from mach taskgraph
decision
to make this complex system more accessible to those trying to
understand or modify it. They allow you to run portions of the
graph-generation process and output the results.
mach taskgraph tasks
- Get the full task set
mach taskgraph full
- Get the full task graph
mach taskgraph target
- Get the target task set
mach taskgraph target-graph
- Get the target task graph
mach taskgraph optimized
- Get the optimized task graph
mach taskgraph morphed
- Get the morphed task graph
See :doc:`how-tos` for further practical tips on debugging task-graph mechanics locally.
Each of these commands takes an optional --parameters
argument giving a file
with parameters to guide the graph generation. The decision task helpfully
produces such a file on every run, and that is generally the easiest way to get
a parameter file. The parameter keys and values are described in
:doc:`parameters`; using that information, you may modify an existing
parameters.yml
or create your own. The --parameters
option can also
take the following forms:
project=<project>
- Fetch the parameters from the latest push on that project
task-id=<task-id>
- Fetch the parameters from the given decision task id
If not specified, parameters will default to project=mozilla-central
.
By default, the above commands will only output a list of tasks. Use -J flag to output full task definitions. For example:
$ ./mach taskgraph optimized -J
Task graphs -- both the graph artifacts produced by the decision task and those
output by the --json
option to the mach taskgraph
commands -- are JSON
objects, keyed by label, or for optimized task graphs, by taskId. For
convenience, the decision task also writes out label-to-taskid.json
containing a mapping from label to taskId. Each task in the graph is
represented as a JSON object.
Each task has the following properties:
kind
- The name of this task's kind
task_id
- The task's taskId (only for optimized task graphs)
label
- The task's label
attributes
- The task's attributes
dependencies
- The task's in-graph dependencies, represented as an object mapping dependency name to label (or to taskId for optimized task graphs)
optimizations
- The optimizations to be applied to this task
task
- The task's TaskCluster task definition.
The results from each command are in the same format, but with some differences in the content:
- The
tasks
andtarget
subcommands both return graphs with no edges. That is, just collections of tasks without any dependencies indicated. - The
optimized
subcommand returns tasks that have been assigned taskIds. The dependencies array, too, contains taskIds instead of labels, with dependencies on optimized tasks omitted. However, thetask.dependencies
array is populated with the full list of dependency taskIds. All task references are resolved in the optimized graph.
The output of the mach taskgraph
commands are suitable for processing with
the jq utility. For example, to extract all
tasks' labels and their dependencies:
jq 'to_entries | map({label: .value.label, dependencies: .value.dependencies})'
An alternate way of searching the output of mach taskgraph
is
gron, which converts json into a format
that's easily searched with grep
gron taskgraph.json | grep -E 'test.*machine.platform = "linux64";'
./mach taskgraph --json | gron | grep ...