.jenkins/perf_test/update_commit_hash.py

import sys
import json

data_file_path = sys.argv[1]
commit_hash = sys.argv[2]

with open(data_file_path) as data_file:
    data = json.load(data_file)

data['commit'] = commit_hash

with open(data_file_path, 'w') as data_file:
    json.dump(data, data_file)