Merge branch 'feature/listen_fds', release v. 0.0.3

.github/workflows/build-test.yml

@@ -1,7 +1,7 @@
 name: Build package, run test matrix, and publish on PyPi
 
 env:
-  BUILD_PYTHON_VERSION: "3.7"
+  BUILD_PYTHON_VERSION: "3.8"
 
 on: [push]
 
@@ -37,7 +37,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.8", "3.9", "3.10", "3.11"]
 
     steps:
       - uses: actions/checkout@v3
@@ -54,12 +54,14 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install pytest
+          pip install mypy
       - name: Install built packages
         run: |
           pip install -U dist/*.whl
       - name: Test with pytest
-        run: |
-          pytest
+        run: pytest
+      - name: Test with mypy
+        run: mypy --install-types --non-interactive src/trick17 tests
 
   pypi-publish:
     needs: test

.pre-commit-config.yaml

@@ -1,5 +1,3 @@
-default_language_version:
-  python: python3.11
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.4.0
@@ -15,6 +13,6 @@ repos:
     hooks:
       - id: black
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: 'v0.0.284'
+    rev: 'v0.0.285'
     hooks:
       - id: ruff

README.md

@@ -27,6 +27,8 @@ pip install trick17
 
 - `daemon.booted()` returns `True` if system was booted by systemd.
 - `daemon.notify(state)` sends a notification to systemd.
+- `listen_fds()` returns an iterator over (fd, name) tuples in case of socket activation,
+  see [systemd.socket](https://www.freedesktop.org/software/systemd/man/systemd.socket.html)
 
 ### trick17.journal
 

pyproject.toml

@@ -7,7 +7,7 @@ name = "trick17"
 dynamic = ["version"]
 description = "Systemd utility functions in pure python"
 readme = "README.md"
-requires-python = ">=3.7"
+requires-python = ">=3.8"
 license = "MIT"
 keywords = [
   "systemd",
@@ -20,7 +20,6 @@ classifiers = [
   "Intended Audience :: Developers",
   "Operating System :: POSIX :: Linux",
   "Programming Language :: Python",
-  "Programming Language :: Python :: 3.7",
   "Programming Language :: Python :: 3.8",
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
@@ -40,6 +39,7 @@ path = "src/trick17/__about__.py"
 [tool.hatch.envs.default]
 dependencies = [
   "coverage[toml]>=6.5",
+  "mypy>=1.0.0",
   "pytest",
 ]
 [tool.hatch.envs.default.scripts]
@@ -53,20 +53,18 @@ cov = [
   "test-cov",
   "cov-report",
 ]
+typing = "mypy --install-types --non-interactive {args:src/trick17 tests}"
 
 [[tool.hatch.envs.all.matrix]]
-python = ["3.7", "3.8", "3.9", "3.10", "3.11"]
+python = ["3.8", "3.9", "3.10", "3.11"]
 
 [tool.hatch.envs.lint]
 detached = true
 dependencies = [
   "black>=23.1.0",
-  "mypy>=1.0.0",
   "ruff>=0.0.243",
-  "pytest",
 ]
 [tool.hatch.envs.lint.scripts]
-typing = "mypy --install-types --non-interactive {args:src/trick17 tests}"
 style = [
   "ruff {args:.}",
   "black --check --diff {args:.}",
@@ -76,17 +74,13 @@ fmt = [
   "ruff --fix {args:.}",
   "style",
 ]
-all = [
-  "style",
-  "typing",
-]
 
 [tool.black]
-target-version = ["py37"]
+target-version = ["py38"]
 line-length = 84
 
 [tool.ruff]
-target-version = "py37"
+target-version = "py38"
 line-length = 84
 select = [
   "A",

src/trick17/__about__.py

@@ -1,4 +1,4 @@
 # SPDX-FileCopyrightText: 2023-present Stefano Miccoli <[email protected]>
 #
 # SPDX-License-Identifier: MIT
-__version__ = "0.0.2"
+__version__ = "0.0.3"

src/trick17/__init__.py

@@ -5,7 +5,11 @@
 # systemd notable paths
 SD_BOOTED_PATH = "/run/systemd/system"
 SD_JOURNAL_SOCKET_PATH = "/run/systemd/journal/socket"
+SD_LISTEN_FDS_START = 3
 
 # environmet variables possibly set by systemd
 SD_JOURNAL_STREAM_ENV = "JOURNAL_STREAM"
 SD_NOTIFY_SOCKET_ENV = "NOTIFY_SOCKET"
+SD_LISTEN_FDS_PID_ENV = "LISTEN_PID"
+SD_LISTEN_FDS_ENV = "LISTEN_FDS"
+SD_LISTEN_FDS_NAMES_ENV = "LISTEN_FDNAMES"

src/trick17/daemon.py

@@ -4,6 +4,7 @@
 
 import os
 from pathlib import Path
+from typing import Iterator, List, Tuple
 
 import trick17
 from trick17 import util
@@ -16,6 +17,54 @@ def booted() -> bool:
     return Path(trick17.SD_BOOTED_PATH).is_dir()
 
 
+def listen_fds() -> Iterator[Tuple[int, str]]:
+    """listen_fds() returns an iterator over (fd, name) tuples, where
+    - fd is an open file descriptor intialized by systemd socket-activation
+    - name is an optional name, '' if undefined.
+    """
+
+    # check pid
+    if trick17.SD_LISTEN_FDS_PID_ENV not in os.environ:
+        return iter(())
+    try:
+        pid = int(os.environ[trick17.SD_LISTEN_FDS_PID_ENV])
+    except ValueError as err:
+        msg = f"Unable to get pid from environment: {err}"
+        raise RuntimeError(msg) from err
+    if os.getpid() != pid:
+        return iter(())
+
+    # check FDS
+    nfds: int
+    try:
+        nfds = int(os.environ[trick17.SD_LISTEN_FDS_ENV])
+    except KeyError as err:
+        msg = f"Unable to get number of fd's from environment: {err}"
+        raise RuntimeError(msg) from err
+    except ValueError as err:
+        msg = f"Parsing of fd's from environment failed: {err}"
+        raise RuntimeError(msg) from err
+    if nfds < 1:
+        msg = f"Invalid number of fd's in environment: {nfds:d}"
+        raise RuntimeError(msg)
+    fds = range(trick17.SD_LISTEN_FDS_START, trick17.SD_LISTEN_FDS_START + nfds)
+    assert len(fds) == nfds
+
+    # check names
+    names: List[str]
+    if trick17.SD_LISTEN_FDS_NAMES_ENV not in os.environ:
+        names = [""] * nfds
+    else:
+        names = os.environ[trick17.SD_LISTEN_FDS_NAMES_ENV].split(os.pathsep)
+        if len(names) > nfds:
+            names = names[:nfds]
+        elif len(names) < nfds:
+            names.extend("" for _ in range(nfds - len(names)))
+    assert len(names) == len(fds)
+
+    return zip(fds, names)
+
+
 def notify(state: str) -> bool:
     """notify 'state' to systemd; returns
     - True if notification sent to socket,

tests/test_daemon.py

@@ -1,3 +1,5 @@
+import pytest
+
 from trick17 import daemon
 
 
@@ -8,3 +10,8 @@ def test_booted():
 def test_notify():
     ret = daemon.notify("READY=1")
     assert ret is False
+
+
+def test_listen_fds():
+    with pytest.raises(StopIteration):
+        next(daemon.listen_fds())

tests/tsock.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+import logging
+import os
+import socket
+import stat
+
+from trick17 import daemon
+
+LISTEN_FDS_START = 3
+
+logging.basicConfig(level=logging.INFO)
+for fd, name in daemon.listen_fds():
+    fstat = os.fstat(fd)
+    if not stat.S_ISSOCK(fstat.st_mode):
+        logging.error("fd %d ('%s') not a socket", fd, name)
+        continue
+    with socket.socket(fileno=fd) as sock:
+        logging.info("fd %d ('%s') bound to '%s'", fd, name, sock.getsockname())
+        if sock.type == socket.SOCK_STREAM:
+            while True:
+                conn, address = sock.accept()
+                logging.info("   remote '%s'", address)
+                with conn:
+                    data = conn.recv(4096)
+                    logging.info("   -> %s", data)
+                    if data.startswith(b"STOP"):
+                        break
+        elif sock.type == socket.SOCK_DGRAM:
+            while True:
+                data = sock.recv(4096)
+                logging.info("   -> %s", data)
+                if data.startswith(b"STOP"):
+                    break
+        else:
+            msg = f"Unknown socket type {sock.type}"
+            raise NotImplementedError(msg)