Calculate image builder composer job duration

composer-stats.py

#!/usr/bin/python
import os
import json
import datetime
import statistics

results = []
dir = "/var/lib/osbuild-composer/jobs/"
for fn in os.listdir(dir):
        f = os.path.join(dir, fn)
        with open(f, "r") as fh:
                j = json.load(fh)
                started = datetime.datetime.fromisoformat(j["started_at"])
                finished = datetime.datetime.fromisoformat(j["finished_at"])
                delta = (finished - started).total_seconds()
                results.append(delta)
                print(f"Job {j["id"]} took {delta}s")

print(f"Mean {statistics.mean(results)}, median {statistics.median(results)}")