feat: add initial pacman Prometheus exporterv1.0.0

Add the first production-ready release of prometheus-pacman-exporter for
collecting pacman package statistics through the node exporter textfile
collector.

Collect installed, explicit, dependency, unrequired, foreign, native,
orphan, and updateable package metrics. Support checkupdates as an
alternative update source and optional AUR update collection through a
configurable command.

Add the Click-based CLI, Prometheus metric definitions, package
metadata, dependency lockfile, README, licensing metadata, and
development configuration.

4 files changed, 443 insertions, 0 deletions

diff --git a/prometheus_pacman_exporter/__init__.py b/prometheus_pacman_exporter/__init__.py
new file mode 100644
index 0000000..baf69dd
--- /dev/null
+++ b/prometheus_pacman_exporter/__init__.py
@@ -0,0 +1,224 @@
+#!/usr/bin/env python3
+
+# SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+import os
+import shlex
+import subprocess
+from pathlib import Path
+from typing import cast
+
+import click_extra as click
+from cloup.constraints import If, require_all
+from prometheus_client import write_to_textfile
+
+from . import metrics
+from .cli import FlexibleColorOption, debug, error, msg
+
+VERSION = "1.0.0"
+DESCRIPTION = "Collect pacman package metrics and export them for Prometheus."
+DATE_OF_CREATION = "2021-05-15"
+DATE_OF_REVISION = "2026-05-08"
+AUTHOR = "Dennis Fink <me+coding@dennisfink.me>"
+LICENSE = "BSD-3-Clause"
+
+
+def print_version(
+    ctx: click.Context, param: click.Parameter | None, value: bool
+) -> None:
+    """Print script metadata (name, version, description, author, dates) and exit.
+
+    :param ctx: Click context injected by :func:`click.pass_context`.
+    """
+    if not value or ctx.resilient_parsing:
+        return
+
+    click.echo(click.style("Scriptname:", fg="red", bold=True) + f" {ctx.info_name}")
+    click.echo(click.style("Version:", fg="green", bold=True) + f" {VERSION}")
+    click.echo(click.style("Description:", fg="yellow", bold=True) + f" {DESCRIPTION}")
+    click.echo(click.style("Author:", fg="blue", bold=True) + f" {AUTHOR}")
+    click.echo(
+        click.style("Date of creation:", fg="magenta", bold=True)
+        + f" {DATE_OF_CREATION}"
+    )
+    click.echo(
+        click.style("Date of revision:", fg="cyan", bold=True) + f" {DATE_OF_REVISION}"
+    )
+    click.echo(click.style("License:", fg="red", bold=True) + f" {LICENSE}")
+
+    click.echo("""Copyright (c) 2026 Dennis Fink <me+coding@dennisfink.me>.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors
+may be used to endorse or promote products derived from this software without
+specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS \"AS IS\" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.""")
+
+    ctx.exit()
+
+
+@click.pass_context
+def run_command(
+    ctx: click.Context, command: list[str]
+) -> subprocess.CompletedProcess[str]:
+    """Run a shell command and return the result.
+
+    Logs the command at debug level before execution. Exits the application
+    with the command's return code if it fails.
+
+    :param ctx: Click context injected by :func:`click.pass_context`.
+    :param command: Command and its arguments.
+    :return: Completed process with stdout and stderr captured.
+    """
+    debug("Running command", " ".join(command), err=True)
+    try:
+        return subprocess.run(
+            command, capture_output=True, encoding="utf-8", check=True
+        )
+    except subprocess.CalledProcessError as e:
+        error(f"Command ({' '.join(command)}) failed with exit code {e.returncode}")
+        if e.stderr:
+            error("stderr:", e.stderr.strip())
+        ctx.exit(e.returncode)
+
+
+@click.command(
+    context_settings={"help_option_names": ("-h", "--help", "-?")}, params=[]
+)
+@click.option(
+    "--textfile-collector-dir",
+    type=click.Path(
+        exists=True,
+        readable=True,
+        writable=True,
+        file_okay=False,
+        allow_dash=False,
+        path_type=Path,
+    ),
+    default="/var/lib/prometheus/node-exporter",
+    help="Directory where the Prometheus collector textfile will be written.",
+)
+@click.option(
+    "--use-checkupdates", "use_checkupdates_flag", is_flag=True, default=False
+)
+@click.option(
+    "--aur", "aur_flag", is_flag=True, default=False, help="Include AUR updates."
+)
+@click.option("--aur-command", help="Command used to check for AUR updates.")
+@click.constraint(
+    If("aur_flag", then=require_all).hidden(), ["aur_flag", "aur_command"]
+)
+@click.option("--color", cls=FlexibleColorOption)
+@click.no_color_option()
+@click.option(
+    "-q",
+    "--quiet",
+    "quiet_flag",
+    is_flag=True,
+    default=False,
+    help="Suppress all non-error output.",
+)
+@click.option(
+    "-v",
+    "--verbose",
+    "verbose_flag",
+    is_flag=True,
+    default=False,
+    help="Enable verbose output.",
+)
+@click.option(
+    "--version",
+    callback=print_version,
+    default=False,
+    expose_value=False,
+    help="Show version information and exit.",
+    is_eager=True,
+    is_flag=True,
+)
+@click.pass_context
+def prometheus_pacman_exporter(
+    ctx: click.Context,
+    textfile_collector_dir: Path,
+    use_checkupdates_flag: bool,
+    aur_flag: bool,
+    aur_command: str | None,
+    quiet_flag: bool,
+    verbose_flag: bool,
+):
+    """Collect pacman package metrics and export them for Prometheus.
+
+    Queries pacman for installed package statistics and available updates, then
+    writes them to a ``.prom`` file for consumption by the Prometheus node
+    exporter textfile collector.
+
+    By default, updateable packages are determined using ``pacman --query
+    --upgrades``. Use ``--use-checkupdates`` to query updates with
+    ``checkupdates`` instead. AUR update metrics can optionally be collected by
+    providing ``--aur`` together with ``--aur-command``.
+    """
+
+    ctx.ensure_object(dict)
+    ctx.obj["debug"] = os.environ.get("DEBUG", "").lower() in ("1", "true", "yes")
+    ctx.obj["quiet"] = quiet_flag
+    ctx.obj["verbose"] = verbose_flag
+
+    debug("Effective configuration:", err=True)
+    debug("  textfile_collector_dir:", str(textfile_collector_dir), err=True)
+    debug("  use_checkupdates:", str(use_checkupdates_flag), err=True)
+    debug("  aur:", str(aur_flag), err=True)
+    debug("  aur_command:", str(aur_command), err=True)
+    debug("  verbose:", str(verbose_flag), err=True)
+    debug("  quiet:", str(quiet_flag), err=True)
+
+    pacman = ["pacman", "--query"]
+    queries = [
+        ([*pacman], metrics.INSTALLED_PACKAGES),
+        ([*pacman, "--explicit"], metrics.EXPLICIT_PACKAGES),
+        ([*pacman, "--deps"], metrics.DEPENDS_PACKAGES),
+        ([*pacman, "--unrequired"], metrics.UNREQUIRED_PACKAGES),
+        ([*pacman, "--foreign"], metrics.FOREIGN_PACKAGES),
+        ([*pacman, "--native"], metrics.NATIVE_PACKAGES),
+        ([*pacman, "--deps", "--unrequired"], metrics.ORPHAN_PACKAGES),
+        (
+            ["checkupdates"] if use_checkupdates_flag else [*pacman, "--upgrades"],
+            metrics.UPDATEABLE_PACKAGES,
+        ),
+    ]
+
+    if aur_flag:
+        queries.append(
+            (shlex.split(cast(str, aur_command)), metrics.AUR_UPDATEABLE_PACKAGES)
+        )
+
+    for command, metric in queries:
+        output = run_command(command)
+        metric.set(len(output.stdout.splitlines()))
+
+    metrics_file = textfile_collector_dir / "pacman.prom"
+    write_to_textfile(str(metrics_file.absolute()), metrics.REGISTRY)
+    msg("Metrics written to:", str(metrics_file.absolute()), err=True)
+
+
+if __name__ == "__main__":
+    prometheus_pacman_exporter()
diff --git a/prometheus_pacman_exporter/__main__.py b/prometheus_pacman_exporter/__main__.py
new file mode 100644
index 0000000..877708c
--- /dev/null
+++ b/prometheus_pacman_exporter/__main__.py
@@ -0,0 +1,7 @@
+# SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+from prometheus_pacman_exporter import prometheus_pacman_exporter
+
+prometheus_pacman_exporter()
diff --git a/prometheus_pacman_exporter/cli.py b/prometheus_pacman_exporter/cli.py
new file mode 100644
index 0000000..5d91b05
--- /dev/null
+++ b/prometheus_pacman_exporter/cli.py
@@ -0,0 +1,161 @@
+# SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""Define Click parameter types and styled terminal message helpers."""
+
+from collections.abc import Callable
+from functools import update_wrapper
+from typing import Any, Concatenate
+
+import click_extra as click
+
+
+class FlexibleColorOption(click.ColorOption):
+    """Allow the color option value to be passed with or without ``=``."""
+
+    _gnu_optional_value = False
+
+
+def pass_obj_silent[T, **P, R](
+    f: Callable[Concatenate[T | None, P], R],
+) -> Callable[P, R]:
+    """Pass the current context object to a callback, if available.
+
+    The current Click context is retrieved silently. If no context exists or
+    its object is not a dictionary, ``None`` is passed instead.
+
+    The context object is inserted as the first positional argument to *f*.
+    """
+
+    def new_func(*args: P.args, **kwargs: P.kwargs) -> R:
+        ctx = click.get_current_context(silent=True)
+        obj = ctx.obj if ctx is not None else None
+        return f(obj, *args, **kwargs)
+
+    return update_wrapper(new_func, f)
+
+
+def emit(
+    prefix: str, color: str, *message: str, enabled: bool = True, err: bool = False
+) -> None:
+    """Render a styled prefix and message to stdout.
+
+    This helper is used by :func:`error`, :func:`msg`, :func:`warn`,
+    :func:`verbose`, and :func:`debug`. The first message argument is rendered in
+    bold and subsequent arguments are appended unstyled.
+
+    :param prefix: Prefix displayed before the message.
+    :param color: Click-compatible color name applied to the prefix.
+    :param message: One or more message parts to display.
+    :param enabled: Whether the message should be emitted.
+    :param err: Write to `stderr` instead of `stdout`.
+    :raises TypeError: If no message arguments are provided.
+    """
+    if not message:
+        raise TypeError("emit() missing 1 required positional argument: 'message'")
+
+    if not enabled:
+        return
+
+    click.echo(
+        " ".join(
+            [
+                click.style(prefix, fg=color, bold=True),
+                click.style(message[0], bold=True),
+                *message[1:],
+            ]
+        ),
+        err=err,
+    )
+
+
+def error(*message: str) -> None:
+    """Print a formatted error message to stdout in red.
+
+    The first argument is rendered in bold and subsequent arguments are appended
+    unstyled. Error messages are always printed regardless of quiet or verbose
+    flags.
+
+    :param message: One or more message parts to display.
+    """
+    emit("==> ERROR:", "red", *message, err=True)
+
+
+@pass_obj_silent
+def msg(obj: dict[str, Any] | None, *message: str, err: bool = False) -> None:
+    """Print a formatted informational message to stdout in green.
+
+    The message is suppressed when the quiet flag is set. When called outside a
+    Click context, the message is emitted normally. The first argument is rendered
+    in bold and subsequent arguments are appended unstyled.
+
+    :param message: One or more message parts to display.
+    """
+    emit(
+        "==>",
+        "green",
+        *message,
+        enabled=obj is None or not obj.get("quiet", False),
+        err=err,
+    )
+
+
+@pass_obj_silent
+def warn(obj: dict[str, Any] | None, *message: str, err: bool = False) -> None:
+    """Print a formatted warning message to stdout in yellow.
+
+    The message is suppressed when the quiet flag is set. When called outside a
+    Click context, the message is emitted normally. The first argument is rendered
+    in bold and subsequent arguments are appended unstyled.
+
+    :param message: One or more message parts to display.
+    """
+    emit(
+        "==>",
+        "yellow",
+        *message,
+        enabled=obj is None or not obj.get("quiet", False),
+        err=err,
+    )
+
+
+@pass_obj_silent
+def verbose(obj: dict[str, Any] | None, *message: str, err: bool = False) -> None:
+    """Print a formatted verbose message to stdout in blue.
+
+    The message is printed only when called from a Click context with the verbose
+    flag set and the quiet flag unset. Calls made outside a Click context are a
+    no-op.
+
+    :param message: One or more message parts to display.
+    """
+    emit(
+        "==>",
+        "blue",
+        *message,
+        enabled=(
+            obj is not None
+            and obj.get("verbose", False)
+            and not obj.get("quiet", False)
+        ),
+        err=err,
+    )
+
+
+@pass_obj_silent
+def debug(obj: dict[str, Any] | None, *message: str, err: bool = False) -> None:
+    """Print a formatted debug message to stdout in magenta.
+
+    The message is printed only when called from a Click context with the debug
+    flag enabled. Calls made outside a Click context are a no-op.
+
+    :param message: One or more message parts to display.
+    """
+    emit(
+        "==>",
+        "magenta",
+        *message,
+        enabled=obj is not None and obj.get("debug", False),
+        err=err,
+    )
diff --git a/prometheus_pacman_exporter/metrics.py b/prometheus_pacman_exporter/metrics.py
new file mode 100644
index 0000000..f8a99fd
--- /dev/null
+++ b/prometheus_pacman_exporter/metrics.py
@@ -0,0 +1,51 @@
+# SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""Prometheus metric definitions for the pacman exporter."""
+
+from prometheus_client import CollectorRegistry, Gauge
+
+REGISTRY = CollectorRegistry(auto_describe=True)
+
+INSTALLED_PACKAGES = Gauge(
+    "pacman_installed_packages",
+    "The current number of installed packages",
+    registry=REGISTRY,
+)
+UPDATEABLE_PACKAGES = Gauge(
+    "pacman_updateable_packages",
+    "The current number of updateable packages",
+    registry=REGISTRY,
+)
+EXPLICIT_PACKAGES = Gauge(
+    "pacman_explicit_packages",
+    "The current number of explicitly installed packages",
+    registry=REGISTRY,
+)
+DEPENDS_PACKAGES = Gauge(
+    "pacman_depends_packages",
+    "The current number of packages installed as dependencies",
+    registry=REGISTRY,
+)
+UNREQUIRED_PACKAGES = Gauge(
+    "pacman_unrequired_packages",
+    "The current number of unrequired packages",
+    registry=REGISTRY,
+)
+FOREIGN_PACKAGES = Gauge(
+    "pacman_foreign_packages",
+    "The current number of foreign packages",
+    registry=REGISTRY,
+)
+NATIVE_PACKAGES = Gauge(
+    "pacman_native_packages", "The current number of native packages", registry=REGISTRY
+)
+ORPHAN_PACKAGES = Gauge(
+    "pacman_orphan_packages", "The current number of orphan packages", registry=REGISTRY
+)
+AUR_UPDATEABLE_PACKAGES = Gauge(
+    "pacman_aur_updateable_packages",
+    "The current number of updates packages from the AUR",
+    registry=REGISTRY,
+)