Disable autostart for non 'server' Rails commands #2239

fallwith · 2023-09-29T18:39:50Z

Previously booting a Rails app via launching the Rails console or running a Rake task would prevent the agent from autostarting, but other Rails commands such as rails routes would still see the agent autostart.

Now the :'autostart.denylisted_constants' config option's default list of constants has been updated to include all of the Rails::Command based command classes that either boot a Rails app or otherwise don't hide via hide_command!.

This existing denylisted constants based approach was chosen given what little we have to work with when taking alternative approaches. When a Rails user runs bin/rails routes in their app directory, the railties/lib/rails/commands.rb file ends up shift-ing the 'routes' value out of ARGV and ARGV is empty ([]) when it reaches the agent. With ARGV not providing us anything to hook into, we have to either rely on walking the callstack to determine a caller or checking for constants to be defined. Given the precedent for checking for constants to ignore Rails console contexts, that approach was built upon to ignore the other Rails CLI/TUI contexts.

resolves #2086

Previously booting a Rails app via launching the Rails console or running a Rake task would prevent the agent from autostarting, but other Rails commands such as `rails routes` would still see the agent autostart. Now the `:'autostart.denylisted_constants'` config option's default list of constants has been updated to include all of the `Rails::Command` based command classes that either boot a Rails app or otherwise don't hide via `hide_command!`. This existing denylisted constants based approach was chosen given what little we have to work with when taking alternative approaches. When a Rails user runs `bin/rails routes` in their app directory, the `railties/lib/rails/commands.rb` file ends up `shift`-ing the `'routes'` value out of `ARGV` and `ARGV` is empty (`[]`) when it reaches the agent. With `ARGV` not providing us anything to hook into, we have to either rely on walking the callstack to determine a caller or checking for constants to be defined. Given the precedent for checking for constants to ignore Rails console contexts, that approach was built upon to ignore the other Rails CLI/TUI contexts.

Rails commands being ignored, PR 2239

fallwith · 2023-09-29T18:59:31Z

NOTE that these additional commands were not skipped over previously due to an oversight or anything. The agent simply predates their existence. The additional commands either did not exist at all previously or were handled differently as Rake tasks, and the agent already ignores some* Rake tasks by default.

lib/new_relic/agent/configuration/default_source.rb

CHANGELOG.md

The agent already has conventions in place for using a separate 'test' environment specific configuration for test running, and for denying specific Rake tasks by name, so do not redundantly disable them by default with the constants denylist. This way, users who wish to use the agent with their tests and Rake tasks can continue to do so.

CHANGELOG.md

Updated CHANGELOG to reflect c6dae08 Co-authored-by: Kayla Reopelle (she/her) <[email protected]>

CHANGELOG.md

@tannalynn

Rails command autostart denylisting - better explain that this impacts Rails 7 users, as Rails 5-6 users who ran something like `rails routes` would have seen the "routes" subcommand handed off to Rake and be handled by the agent's Rake related denylist functionality. Thanks, @tannalynn! Co-authored-by: Tanna McClure <[email protected]>

CHANGELOG.md

@kaylareopelle

CHANGELOG entry for newly ignored Rails commands, thanks @kaylareopelle Co-authored-by: Kayla Reopelle (she/her) <[email protected]>

github-actions · 2023-09-29T23:20:41Z

SimpleCov Report

	Coverage	Threshold
Line	94.32%	94%
Branch	85.84%	85%

fallwith requested review from hannahramadan, kaylareopelle and tannalynn as code owners September 29, 2023 18:39

CHANGELOG: entry for PR 2239

99d8be2

Rails commands being ignored, PR 2239

kaylareopelle reviewed Sep 29, 2023

View reviewed changes

lib/new_relic/agent/configuration/default_source.rb Outdated Show resolved Hide resolved

tannalynn reviewed Sep 29, 2023

View reviewed changes