Rails' default request logging is easy to read for humans but difficult for log aggregators such as Kibana, Graylog and Splunk. Superlogger transforms the logs into JSON for easy parsing and adds useful details like Timestamp, Session ID and Request ID for tracing purposes.
Default rails logging:
Started GET "/home/index" for ::1 at 2016-04-29 17:31:12 +0800
ActiveRecord::SchemaMigration Load (0.1ms) SELECT "schema_migrations".* FROM "schema_migrations"
Processing by HomeController#index as HTML
Something Load (0.1ms) SELECT "somethings".* FROM "somethings" WHERE "somethings"."paper" = ? AND "somethings"."stone" = ? ORDER BY "somethings"."id" ASC LIMIT 1 [["paper", "123"], ["stone", "456"]]
Rendered home/_partial.html.erb (0.2ms)
Rendered home/index.html.erb within layouts/application (3.4ms)
Completed 200 OK in 135ms (Views: 130.7ms | ActiveRecord: 0.3ms)
Started GET "/assets/application.self-e80e8f2318043e8af94dddc2adad5a4f09739a8ebb323b3ab31cd71d45fd9113.css?body=1" for ::1 at 2016-04-29 17:31:12 +0800
Started GET "/assets/application.self-8f06a73c35179188914ab50e057157639fce1401c1cdca640ac9cec33746fc5b.js?body=1" for ::1 at 2016-04-29 17:31:12 +0800
With Superlogger:
{"level":"debug","ts":1590972589.522784,"caller":"superlogger/active_record_log_subscriber:21","sql":"SELECT \"schema_migrations\".\"version\" FROM \"schema_migrations\" ORDER BY \"schema_migrations\".\"version\" ASC","params":[],"duration":0.13}
{"level":"info","ts":1590972589.526133,"caller":"superlogger/superlogger_middleware:21","session_id":"90e90c75c72c","request_id":"34432478c89b4d8591e02e0169b40a56","method":"GET","path":"/home/index"}
{"level":"debug","ts":1590972589.546272,"caller":"superlogger/action_controller_log_subscriber:8","session_id":"90e90c75c72c","request_id":"34432478c89b4d8591e02e0169b40a56","controller":"HomeController","action":"index","params":{}}
{"level":"debug","ts":1590972589.55092,"caller":"superlogger/active_record_log_subscriber:21","session_id":"90e90c75c72c","request_id":"34432478c89b4d8591e02e0169b40a56","sql":"SELECT \"somethings\".* FROM \"somethings\" WHERE \"somethings\".\"paper\" = ? AND \"somethings\".\"stone\" = ? ORDER BY \"somethings\".\"id\" ASC LIMIT ?","params":["123","456","1"],"duration":0.22}
{"level":"debug","ts":1590972589.574199,"caller":"superlogger/action_view_log_subscriber:6","session_id":"90e90c75c72c","request_id":"34432478c89b4d8591e02e0169b40a56","view":"_partial.html.erb","duration":0.33}
{"level":"debug","ts":1590972589.574795,"caller":"superlogger/action_view_log_subscriber:6","session_id":"90e90c75c72c","request_id":"34432478c89b4d8591e02e0169b40a56","view":"index.html.erb","duration":2.95}
{"level":"info","ts":1590972589.61165,"caller":"superlogger/action_controller_log_subscriber:20","session_id":"90e90c75c72c","request_id":"34432478c89b4d8591e02e0169b40a56","view_duration":54.59,"db_duration":0.85}
{"level":"info","ts":1590972589.611928,"caller":"superlogger/superlogger_middleware:30","session_id":"90e90c75c72c","request_id":"34432478c89b4d8591e02e0169b40a56","method":"GET","path":"/home/index","response_time":85.65,"status":200}Add superlogger to your application's Gemfile
gem "superlogger"Execute:
$ bundleAnd add the following in config/environment/production.rb
config.logger = Superlogger::Logger.new(STDOUT)By default, Superlogger is only enabled in production environment because JSON is easy for machines to parse but difficult for humans to read. To forcefully enable Superlogger in non-production environment, set in config/application.rb:
Superlogger.enabled = trueLog as per normal using Rails.logger.
Rails.logger.info foo:'true', bar: 'false'
Rails.logger.info "Meatball"ts= Unix Epoch timestampsession_id= Truncated to 12 charactersrequest_id= 32 charactersmsg= If values given is not a hash, it is treated as{"msg":<value>"}- All duration related fields are in milliseconds
To log additional fields that are available on the ActionDispatch::Request object, set in config/application.rb:
Superlogger.include_log_fields = lambda do |request|
# Return a hash of extra fields to log.
{
user_id: request.session[:current_user].id,
ip: request.ip
}
endTo run the tests for Superlogger:
rake test- Bump the version in
lib/superlogger/version.rb. - Run
bundle installto update the version of Superlogger inGemfile.lock. - Open a pull request with the changes from the above steps.
- After the pull request is merged, publish a new release on GitHub with the same version tag.
- Clear all temporary files to prevent them from being bundled into the gem. This is most easily achieved by building from a new clone of the repository.
- Run
gem build superlogger.gemspecto build the gem. - Run
gem push superlogger-x.x.x.gemto publish the gem to RubyGems. You will be prompted for credentials if this is your first time publishing the gem on your machine.