HAR Record / Replay

Overview

The HAR importer turns recorded HTTP traffic (HAR JSON) into a list of LoadDensity tasks or a complete runnable action JSON. Capture HAR via Chrome / Firefox DevTools, mitmproxy, Charles, or any tool that exports the HAR 1.2 format.

Python API

from je_load_density import load_har, har_to_tasks, har_to_action_json

har = load_har("recording.har")
tasks = har_to_tasks(har, include=[r"example\.com"], exclude=[r"\.svg$"])
action_json = har_to_action_json(
    har,
    user="fast_http_user",
    user_count=20,
    spawn_rate=10,
    test_time=120,
    include=[r"api\.example\.com"],
)

Filters

include — list of regex patterns; an entry is kept only if its URL matches any pattern.
exclude — list of regex patterns; an entry is dropped if its URL matches any pattern.

Mapping rules

HTTP method, URL, and request headers are copied directly.
Hop-by-hop and HTTP/2 pseudo headers (host, content-length, connection, :authority, …) are stripped.
JSON request bodies (application/json MIME) are parsed into the json field; form params become data dicts; raw text bodies fall back to data strings.
The captured response status becomes a status_code assertion on the generated task.

Action JSON

{"load_density": [
  ["LD_har_to_action_json", {
    "har": {"log": {...}},
    "user": "fast_http_user",
    "user_count": 20,
    "spawn_rate": 10,
    "test_time": 120
  }]
]}

The result of LD_har_to_action_json is itself an action JSON that can be saved or piped into LD_execute_action.