pympacds-http

HTTP client service for pympacds. Sends data over HTTP on behalf of other services and exposes it over D-Bus, with automatic retry and optional mutual TLS.

Features

• Fire-and-forget D-Bus API: send, download, and request each return a random request token immediately; the result is delivered asynchronously via the request_completed(token, result) signal, so callers correlate a call with its outcome by token.
• A single pooled aiohttp.ClientSession (native asyncio, no thread offloading), created at startup with no network I/O and closed on shutdown.
• Automatic retry of transient failures (network error, timeout, HTTP 5xx) with exponential backoff (retries, retry_backoff_s).
• TLS verification control (tls_verify) plus mutual TLS via tls_certfile/tls_keyfile (must be provided together).
• download / request with a download_path write the response body atomically to disk (temp file + rename) for binary/large downloads.
• Runtime configuration: [http] keys are writable via the framework ConfigContract.
• Exports the framework HealthContract (always) and ConfigContract (opt-in via [dbus] contract_config = true) alongside the HTTP contract.

Why aiohttp

The service uses aiohttp because it is asyncio native: requests run directly on the framework's single event loop with no thread offloading. It is isolated in this service's own package, so the core pympacds framework keeps its zero-dependency property (the core's httpconfprov middleware continues to use the stdlib urllib.request).

Installation

Using PIP

pip install pympacds-http

Using pip installs the Python package only — the D-Bus policy and systemd unit are not installed. You can still run the service directly with pympacds-http -c /etc/pympacds/http.ini, or register and enable it system-wide with the admin script. Since there is no packaged unit, pass the pip-installed executable via --program so the unit is generated:

sudo pympacds-admin setup                      # one-time: user, log dir, D-Bus policy
sudo pympacds-admin install http \
    --program "$(command -v pympacds-http)" \
    --config /etc/pympacds/http.ini --start

Alternatively, install the Debian package (see below), which already ships the unit and policy.

Using PPA

Debian packages are provided through launchpad ppa (dargor0/mpacds):

sudo add-apt-repository ppa:dargor0/mpacds
sudo apt update
sudo apt install python3-pympacds-http

The package installs the service system-wide (executable, systemd unit, D-Bus policy, and the http.ini.example config) and depends on python3-pympacds.

Repository has been tested on Ubuntu (plucky, resolute, stonking) and Debian (stable, testing, unstable).

Configuration

The service reads its parameters from the [http] INI section (see config/http.ini.example). Key options:

Run with:

pympacds-http -c /etc/pympacds/http.ini

D-Bus API

Interface org.pympacds.HTTP at object path /org/pympacds/http:

All sends are fire-and-forget: the method returns immediately with a randomized token, the request runs asynchronously, and request_completed is emitted with the full JSON outcome:

{
  "status_code": 200,
  "url": "https://example.com/api",
  "elapsed_ms": 123,
  "body": "...",
  "download_path": null,
  "bytes_written": null,
  "error": null
}

The framework HealthContract (at .../health) and ConfigContract ([dbus] contract_config = true) are also exported.