When your application is running on a multi-server setup, application logs are stored per server (unless you choose a centralized logging solution).
Here is a Capistrano task that connects to all servers and prints logs to your terminal like this:
$ cap production app:logs
00:00 app:logs
01 tail -n0 -F /var/www/your-application/shared/log/production.log | while read line; do echo "$(hostname): $line"; done
01 app01-prod: Started GET "/sign_in" for 1.2.3.4 at 2018-04-26 11:28:19 +0200
01 app01-prod: Processing by Users::SessionsController#new as HTML
01 app01-prod: Rendering devise/sessions/new.haml within layouts/signed_out
01 app01-prod: Rendered devise/sessions/new.haml within layouts/signed_out (4.8ms)
01 app01-prod: Rendered layouts/shared/_head.haml (0.5ms)
01 app01-prod: Completed 200 OK in 8ms (Views: 6.1ms | ActiveRecord: 0.0ms)
01 app02-prod: Started GET "/messages/number_of_new" for 5.6.7.8 at 2018-04-26 11:28:20 +0200
01 app02-prod: Processing by MessagesController#number_of_new as */*
01 app02-prod: Rendering text template
01 app02-prod: Rendered text template (0.0ms)
01 app02-prod: Completed 200 OK in 23ms (Views: 1.0ms | ActiveRecord: 7.2ms)
Store the following task in a file like lib/capistrano/tasks/app.rake.
namespace :app do
desc 'Tail remote log files'
task :logs do
on roles :app do
logfile = ENV['LOG'] || fetch(:rails_env)
execute %(tail -n0 -F #{shared_path}/log/#{logfile}.log | while read line; do echo "$(hostname): $line"; done)
end
end
end
If you have some other log file that you want to tail, use the LOG env variable, like LOG=sidekiq cap production app:logs.
Note that Capistrano truncates lines that are longer than your terminal. This can be painful when looking at logs, and we recommend you disable truncation entirely.
Posted by Arne Hartherz to makandra dev (2018-04-26 09:35)