cln-plugins/prometheus

Prometheus plugin for c-lightning

This plugin exposes some key metrics from c-lightning in the prometheus format so it can be scraped, plotted and alerts can be created on it. The plugin adds the following command line arguments:

• prometheus-listen: the IP address and port to bind the HTTP server to (default: 127.0.0.1:9750)

Exposed variables include:

• node: ID, version, ...
• peers: whether they are connected, and how many channels are currently open
• channels: fund allocations, spendable funds, and how many unresolved HTLCs are currently attached to the channel
• funds: satoshis in on-chain outputs, satoshis allocated to channels and total sum (may be inaccurate during channel resolution).

Installation

Using uv (recommended)

• Install uv and make the plugin executable

pip install --upgrade pip uv
chmod a+x prometheus.py

Then you can add just that file to your Core Lightning plugins directory. The plugin should start automatically and its dependencies will be installed on-the-fly when the node comes up.

Using poetry (legacy)

If you don't want to use uv, you can still use poetry. You need to update the shebang line to point the OS at the correct interpreter (python3) though:

sed -i 's#-S uv run --script#python3#' prometheus.py

Then install poetry and build the package:

pip install --upgrade pip poetry
poetry install --only main

This is an example snippet for installing the plugin's dependencies and cleaning up afterwards:

PLUGIN_PATH=/opt/plugins
RAW_GH_PLUGINS=https://raw.githubusercontent.com/lightningd/plugins/master
mkdir -p ${PLUGIN_PATH}

pip3 install --break-system-packages --upgrade pip wheel poetry

# Add custom plugins (prometheus)
## This replaces the shebang line that by default uses uv for package management
(cd $PLUGIN_PATH; wget -q $RAW_GH_PLUGINS/prometheus/README.md \
  && wget -q $RAW_GH_PLUGINS/prometheus/pyproject.toml \
  && wget -q $RAW_GH_PLUGINS/prometheus/poetry.lock \
  && wget -q $RAW_GH_PLUGINS/prometheus/prometheus.py \
  && sed -i 's#-S uv run --script#python3#' prometheus.py \
  && poetry config virtualenvs.create false \
  && PIP_BREAK_SYSTEM_PACKAGES=1 poetry install --only main \
  && rm -f README.md pyproject.toml poetry.lock)

chmod a+x $PLUGIN_PATH/*