Glossary

Action

A unit of work a step runs with uses, described by its file action.yml - see GitHub’s metadata syntax. It runs JavaScript, a Docker container, or steps of its own (composite action). See Action File.

Composite Action

An action running steps of its own - runs.using: composite. See GitHub’s custom actions.

Domain

A Sphinx domain groups the directives and roles describing objects of one kind, under a name like py or gha. See Overview.

DOT

The graph description language of Graphviz, which the pipeline graph is written in.

Gantt Chart

A bar chart of timespans on a time axis, a row per task. See Gantt Chart.

Wikipedia: Gantt chart

GITHUB_TOKEN

The token GitHub creates for every workflow run, with the permissions the workflow and its jobs declare. See GitHub’s GITHUB_TOKEN.

Job

A set of steps running on one runner, or a call of a reusable workflow. Jobs run in parallel unless they need each other. See GitHub’s workflow syntax.

Matrix

A job’s strategy.matrix: the job runs once per combination of the matrix’ dimensions. See GitHub’s job variations.

Needs

The jobs a job depends on, which have to complete before it starts. See GitHub’s jobs.<job_id>.needs.

OTLP

The OpenTelemetry Protocol, which carries traces to a collector or viewer; its JSON encoding is OTLP/JSON. See Pipeline Trace Diagram.

Pipeline

Workflow Run

One run of a workflow, with the jobs it ran, read from GitHub’s REST API - its workflow runs and workflow jobs. See Pipeline Run.

Reusable Workflow

A workflow triggered by on.workflow_call, which a job of another workflow calls with uses, passing inputs and secrets. See GitHub’s reusable workflows.

Runner

The machine a job runs on, requested by the labels in runs-on. See GitHub’s runners.

Span

A timespan of a trace, with a name, a begin and an end, attributes, and the spans below it. See OpenTelemetry’s traces.

Step

A task of a job or a composite action: a script in run, or an action in uses.

Trace

A tree of spans recording where time went. The trace of a pipeline has a span for every called workflow, matrix, job and step, with the attributes of OpenTelemetry’s semantic conventions for CI/CD. See Pipeline Trace Diagram.

Workflow

A YAML file below .github/workflows describing what runs when it is triggered: its jobs, and the steps of each. See GitHub’s workflows and Workflow File.