LogDevice implementation that post logs on a Slack channel.
Just add this into your Gemfile:
gem 'slack_log_device'Then, just run a bundle install.
require 'slack_log_device'
logger = Logger.new(SlackLogDevice.new(webhook_url: 'https://hooks.slack.com/services/...', username: 'MyApp'))
logger.level = Logger::INFO
logger.warn('BAM!')Then, the logged message will be writen to webhook's configured channel.
Note that the messages written are buffered in order to avoid consecutive request.
auto_flush: To flush messages directly when a message is written (disabled by default).channel: The channel to post message on (webhook configured channel by default). It can be a channel (if starting with#) or a specific user (if starting with a@).flush_delay: The delay in seconds to send buffered messages (1 by default).max_buffer_size: The max messages count to flush them (10 messages by default).timeout: The timeout in seconds to send message to slack (5 by default).username: The username to post message as (nil by default).webhook_url: The URL of the webhook (mandatory).
slack_log_device provides a log formatter to have a pretty output for slack.
It can be configured like this:
logger.formatter = SlackLogDevice.formatterSlackLogDevice.formatter method also accepts block to transform logged
message, example:
logger.formatter = SlackLogDevice.formatter { |message| message.reverse }By default, formatter adds those metadata:
PID: The current process id.User: The current user (ENV['USER']).Machine: The machine name (hostname).
To disable default metadata (User, Machine and PID), set
disable_default_metadata formatter option to true.
You can also add custom metadata to message sent to slack, here is how to do it:
logger.formatter = SlackLogDevice.formatter(extra_metadata: {
'Exception class' => -> (options) { options[:exception].class.name },
'System' => `uname -a`,
})As you can see, blocks (invoked with options contains request and
exception) are supported.
Exception backtrace is automatically stripped to 10 lines. You can change
this behavior via :max_backtrace_lines:
logger.formatter = SlackLogDevice.formatter(max_backtrace_lines: 50)- A value of
0will not print backtrace. - A value of
-1will not strip backtrace.
If you use Ruby on Rails, you will get some metadata like current HTTP method, URL, remote address and User-Agent (see Rails configuration section).
If you need more, use :extra_metadata option. Note that blocks specified
with :extra_metadata option are invoked with options that may contains
:request option (if present).
By default, there is a different icon emoji for each logging severity level. But, it can be configured:
logger.formatter = SlackLogDevice.formatter(max_backtrace_lines: 50, icon_emojis: { fatal: ':metal:', warn: ':skull:' })Or for all severity levels:
logger.formatter = SlackLogDevice.formatter(max_backtrace_lines: 50, icon_emoji: ':metal:')For a rails application, it is recommanded to use following configuration into
config/environments/production.rb file:
SlackLogDevice.enable_rails_logging!
config.logger = ActiveSupport::Logger.new(SlackLogDevice.new(webhook_url: 'https://hooks.slack.com/services/...', username: 'MyRailsApp'))
config.logger.formatter = SlackLogDevice.formatter
config.log_level = :warnSlackLogDevice.enable_rails_logging! instruction put current request into
thread in order to make it available by slack formatter.
This project is fully tested with Rspec 3.
Just run bundle exec rake (after a bundle install).