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russell@unturf.com ca022a8f0d
tests: OTP 25/26 + TLS + Elixir GenServer integration via docker
Reproduces the production failure locally so we can iterate in seconds
instead of waiting on deploy cycles across 3 repos and PyPI.

Existing test_node.py / test_tls.py use the system Erlang which is
OTP 24 on most dev boxes (Ubuntu 22.04 default) — silently masks
flag-negotiation and protocol bugs that only surface against OTP 25+.

Adds four docker-backed tests:
  - plain dist + hand-coded receive  (works on all OTP versions)
  - TLS dist + hand-coded receive    (works on all OTP versions)
  - TLS dist + Elixir GenServer      (FAILS on OTP 25, passes on 26)

The last one is the minimum repro of the portal@unsandbox.com failure
mode. Once a fix lands, that test goes green and we know the
production smoke test will too.

Uses --network host to share the host's epmd (Linux-only). Docker mounts
from $HOME/.erldistpy-test/ because snap-confined docker can't see /tmp.
Tests skip cleanly when docker isn't installed.
2026-06-17 09:24:57 -04:00
docs ci: classic auth via group-scoped TWINE_USERNAME/TWINE_PASSWORD, v0.1.4 2026-06-16 15:01:23 -04:00
erldistpy 0.1.7: declare DFLAG_MANDATORY_25_DIGEST + decode dist-header replies 2026-06-17 08:51:09 -04:00
tests tests: OTP 25/26 + TLS + Elixir GenServer integration via docker 2026-06-17 09:24:57 -04:00
.gitignore phase 6: TLS dist via inet_tls_dist 2026-06-16 12:06:07 -04:00
.gitlab-ci.yml ci: modern twine, classic auth via group vars, v0.1.6 2026-06-16 15:18:54 -04:00
LICENSE phase 0 + 1: repo bones and ETF codec 2026-06-16 10:39:01 -04:00
Makefile packaging: ship to PyPI via tag + GitLab CI (mirrors ago's pattern) 2026-06-16 13:45:08 -04:00
pyproject.toml 0.1.7: declare DFLAG_MANDATORY_25_DIGEST + decode dist-header replies 2026-06-17 08:51:09 -04:00
README.md packaging: ship to PyPI via tag + GitLab CI (mirrors ago's pattern) 2026-06-16 13:45:08 -04:00

erldistpy

Native Python client for our Erlang distribution protocol. Talk Erlang/Elixir nodes from CPython without HTTP shim layers.

Built to swap into Python web apps as a drop-in for HTTP wallet-bridge clients (see unfeed's WalletTransport and make_post_sell's crypto watcher) so they can call Elixir gen_server processes over native Erlang dist instead of JSON-RPC or HTTPS. Same call semantics, lower latency, fewer moving parts.

Install

pip install erldistpy

Quick start

from erldistpy import Node, Atom

with Node(
    our_name="myapp@host",
    peer_name="wallet",                # short EPMD name
    peer_host="wallet.example.com",
    cookie="SHARED_COOKIE",            # read from a file path, never inline
) as node:
    reply = node.call(
        "Elixir.Wallet.Service",
        (Atom("monero"), Atom("get_height"), []),
        timeout=5.0,
    )
    # reply is whatever the gen_server returned — atoms / binaries /
    # tuples / maps / lists / pids / refs decode to Python natives.

For TLS dist (Erlang inet_tls_dist):

from erldistpy import Node, make_dist_tls_context

ctx = make_dist_tls_context(
    cert="/etc/myapp/client.pem",
    key="/etc/myapp/client.key",
    ca="/etc/myapp/ca.pem",
)
node = Node(our_name=..., peer_name=..., cookie=..., tls_context=ctx)

Scope

  • ETF (External Term Format) codec — encode/decode Erlang terms
  • EPMD client — node name → port lookup
  • v6 distribution handshake — MD5 cookie auth, version negotiation
  • gen_call to registered processes on a remote node
  • TLS dist support (Erlang inet_tls_dist)

Out of scope: full Erlang node impersonation, link/monitor lifecycles, distributed Mnesia. We are a client, not a peer node.

Why not Pyrlang?

Pyrlang implements a full asyncio Erlang node. Heavy, asyncio-first, complex. erldistpy is a small synchronous client that fits behind the same Protocol surface as httpx. Different shape, different audience.

Development

make bootstrap   # create venv, install editable + dev deps
make test        # run pytest (122 tests)
make lint        # ruff check
make build       # build sdist + wheel into dist/
make dist-check  # twine check dist/*

See docs/ROADMAP.md for the phase-by-phase build log.

License

Unlicense (public domain).