chore: add script to turn workflow job log into chrome://tracing blob

.maintainer-scripts/workflow-tracing.py

@@ -0,0 +1,111 @@
+#!/usr/bin/env python3
+
+import json
+import argparse
+from datetime import datetime
+
+
+# Use:
+#   gh api --paginate /repos/mhx/dwarfs/actions/runs/14559408056/jobs > jobs.json
+#   python3 workflow-tracing.py -i jobs.json -o trace.json
+
+
+def parse_iso8601(ts: str) -> datetime:
+    """
+    Parse an ISO8601 timestamp, stripping a trailing 'Z' if present.
+    """
+    if ts.endswith("Z"):
+        ts = ts[:-1]
+    return datetime.fromisoformat(ts)
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Convert GitHub Actions job+step timings into a Chrome tracing JSON"
+    )
+    parser.add_argument(
+        "-i",
+        "--input",
+        default="jobs.json",
+        help="Path to the input JSON from `gh api /actions/runs/.../jobs`",
+    )
+    parser.add_argument(
+        "-o",
+        "--output",
+        default="trace.json",
+        help="Path to write the Chrome tracing JSON",
+    )
+    args = parser.parse_args()
+
+    # Load the GitHub API output
+    with open(args.input, "r") as f:
+        data = json.load(f)
+
+    # The API may nest under 'jobs'
+    jobs = data.get("jobs", data)
+    events = []
+
+    job_events = 0
+
+    for job in jobs:
+        # Job-level event
+        if job.get("started_at") and job.get("completed_at"):
+            job_id = job.get("id", 0)
+            name = job.get("name", f"job-{job_id}")
+            runner_id = job.get("runner_name", f"runner-{job_id}")
+
+            start = parse_iso8601(job["started_at"])
+            end = parse_iso8601(job["completed_at"])
+            ts = int(start.timestamp() * 1e6)
+            dur = int((end - start).total_seconds() * 1e6)
+
+            if dur > 0:
+                job_events += 1
+                events.append(
+                    {
+                        "name": name,
+                        "cat": "job",
+                        "ph": "X",
+                        "ts": ts,
+                        "dur": dur,
+                        "pid": runner_id,
+                        "tid": 0,
+                    }
+                )
+
+                # Step-level events
+                for step in job.get("steps", []):
+                    if step.get("started_at") and step.get("completed_at"):
+                        s = parse_iso8601(step["started_at"])
+                        e = parse_iso8601(step["completed_at"])
+                        ts_s = int(s.timestamp() * 1e6)
+                        dur_s = int((e - s).total_seconds() * 1e6)
+                        if dur_s > 0:
+                            events.append(
+                                {
+                                    "name": step.get("name"),
+                                    "cat": "step",
+                                    "ph": "X",
+                                    "ts": ts_s,
+                                    "dur": dur_s,
+                                    "pid": runner_id,
+                                    "tid": 0,
+                                }
+                            )
+            else:
+                print(
+                    f"Job {name} has zero duration: {job['started_at']} -> {job['completed_at']}"
+                )
+
+    # Compose the trace
+    trace = {"traceEvents": events}
+
+    # Write out
+    with open(args.output, "w") as f:
+        json.dump(trace, f, indent=2)
+
+    print(f"Wrote {len(events)} events ({job_events} job events) to {args.output}")
+
+
+if __name__ == "__main__":
+    main()