passenger-datadog

A continuation of the abandoned passenger_datadog gem by Ryan Rosenblum, maintained by IronCloud.

Inspired by passengeri-datadog-monitor

This gem can be used to send stats from Passenger to Datadog. It makes use of the command passenger-status, and the Ruby implementation of statsd provided by dogstatsd-ruby.

In order to gather stats on all Passenger instances, Passenger recommends running passenger-status as root. Therefore, it is recommended that passenger-datadog be run as root as well.

If running passenger-datadog as a user other than the user that owns the application in Passenger, make sure that same version of Passenger is installed for both users.

Installation

$ gem install passenger-datadog

Support

• Ruby >= 3.3
• Passenger >= 6.0

Usage

Foreground process

$ passenger-datadog

The process collects Passenger stats and sends them to Datadog every 30 seconds. It runs in the foreground and shuts down cleanly on SIGTERM/SIGINT.

As a systemd service

Generate and install a unit for this host, then start it:

$ sudo passenger-datadog install-service
$ sudo systemctl enable --now passenger-datadog

install-service resolves the Ruby interpreter, the executable, and passenger-status on the machine it runs on, and writes those absolute paths into /etc/systemd/system/passenger-datadog.service. Use --dry-run to print the unit without writing it, and uninstall-service to remove it.

Under rvm/rbenv/asdf, sudo drops the gem environment, so pass it through:

$ sudo env PATH="$PATH" GEM_HOME="$GEM_HOME" GEM_PATH="$GEM_PATH" \
    passenger-datadog install-service

Regenerate the unit with --force after a Ruby upgrade. See docs/systemd.md for the full guide.

Release

Releases use RubyGems trusted publishing — no API tokens. The trusted publisher must be registered for this repo and the release.yml workflow on RubyGems.org (a pending publisher becomes a normal one after its first push). To release:

1. Bump the version in passenger_datadog.gemspec and add a CHANGELOG.md entry.
2. Commit, tag, and push:

$ git tag v2.0.0
$ git push origin v2.0.0

.github/workflows/release.yml builds the gem and pushes it to RubyGems.org, authenticating with an OIDC token scoped to this gem.