uninitialized constant Puma::Cluster

[Fudoshiki]

Rails master 6.0.0.beta1
Puma master

puma.rb

max_threads_count = ENV.fetch('RAILS_MAX_THREADS') { 5 }
min_threads_count = ENV.fetch('RAILS_MIN_THREADS') { max_threads_count }
threads min_threads_count, max_threads_count
environment ENV.fetch('RAILS_ENV') { 'development' }
workers ENV.fetch('WEB_CONCURRENCY') { 2 }
bind ENV.fetch('PUMA_SOCK') { 'unix://tmp/sockets/puma.sock' }
state_path ENV.fetch('SERVER_STATE') { 'tmp/pids/puma.state' }
activate_control_app ENV.fetch('PUMACTL_SOCK') { 'unix://tmp/sockets/pumactl.sock' }
pidfile 'tmp/pids/puma.pid'
worker_timeout 10
plugin :tmp_restart

/usr/local/rvm/bin/rvm 2.6.1 do bundle exec pumactl -S ~/repository/shared/tmp/pids/puma.state -F ~/repository/current/config/puma.rb stop
uninitialized constant Puma::Cluster
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/lib/puma/dsl.rb:455:in `worker_timeout'
/srv/webapp/repository/current/config/puma.rb:69:in `_load_from'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/lib/puma/dsl.rb:43:in `instance_eval'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/lib/puma/dsl.rb:43:in `_load_from'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/lib/puma/configuration.rb:194:in `block in load'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/lib/puma/configuration.rb:194:in `each'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/lib/puma/configuration.rb:194:in `load'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/lib/puma/control_cli.rb:85:in `initialize'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/bin/pumactl:5:in `new'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bundler/gems/puma-0991396844fe/bin/pumactl:5:in `<top (required)>'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bin/pumactl:23:in `load'
/srv/webapp/repository/shared/bundle/ruby/2.6.0/bin/pumactl:23:in `<top (required)>'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/cli/exec.rb:74:in `load'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/cli/exec.rb:74:in `kernel_load'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/cli/exec.rb:28:in `run'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/cli.rb:463:in `exec'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/vendor/thor/lib/thor.rb:387:in `dispatch'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/cli.rb:27:in `dispatch'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/vendor/thor/lib/thor/base.rb:466:in `start'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/cli.rb:18:in `start'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/exe/bundle:30:in `block in <top (required)>'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/lib/bundler/friendly_errors.rb:124:in `with_friendly_errors'
/srv/webapp/.rvm/gems/ruby-2.6.1/gems/bundler-2.0.1/exe/bundle:22:in `<top (required)>'
/srv/webapp/.rvm/gems/ruby-2.6.1/bin/bundle:23:in `load'
/srv/webapp/.rvm/gems/ruby-2.6.1/bin/bundle:23:in `<main>'

[MSP-Greg]

The error (uninitialized constant Puma::Cluster) is from puma/dsl.rb:466, which is required by puma/configuration.

puma/lib/puma/dsl.rb

Lines 464 to 466 in ca03c52

	def worker_timeout(timeout)
	timeout = Integer(timeout)
	min = Cluster::WORKER_CHECK_INTERVAL

The code causing the error was due to commit 64db36c, 'Enforce a minimum worker_timeout' on 2019-01-24.

With the error shown, the call stack starts with puma/control_cli

puma/control_cli.rb:242 (#start) which requires:
puma/cli                         which requires:
puma.launcher                    which requires:
puma/cluster

Options to fix:

1. In control_cli, move require 'puma/cli' from the start method to the initialize method.

2. In puma/dsl, add require 'puma/cluster' to the worker_timeout method.

3. Adding require elsewhere.

[schneems]

It looks like that line in the control_cli was added in 274350a about 6 years ago. I generally don't like having requires in methods unless there's a really good reason.

I don't see a downside to having the require be outside of the method and at the top of the file, though feel free to let me know if that causes issues.

[MSP-Greg]

I generally don't like having requires in methods unless there's a really good reason.

Agreed. I didn't mention that puma/cli.rb requires puma, so I wasn't sure if it was a circular require issue. I haven't looked into all the various ways one can start Puma, so I left it alone.

puma/lib/puma.rb

Lines 11 to 14 in 2f57c8e

	module Puma
	autoload :Const, 'puma/const'
	autoload :Server, 'puma/server'
	autoload :Launcher, 'puma/launcher'

Since it's autoloading three files, maybe add :Cluster?

[schneems]

Can you try out a fix on a branch and we can see if the tests pass? I'm fine with an autoload, but it does seem like overkill for that one little constant. I think once we get this fix in then we can probably ship another version I'm working on a history.md now. Actually looks like there are other release plans.

[MSP-Greg]

I'll give a try with Autoload. Dumb question - if we're autoloading Cluster, should the same be done with Single?

Actually looks like there are other release plans.

nio4r? etc?

[schneems]

nio4r? etc?

Likely, a slightly more purposeful release rather than just the cobbled together remnants of master. Ideally targeting RailsConf timeframe.

[nateberkopec]

We should probably just Zeitwerk everything for the future, eh?