LumberYak provides a drop in solution for structured logging in Rails applications. So you can easily slice and dice them in your log analysis tool of choice.
Some features include:
- Drop in formatting of logs in JSON.
- Native integration with LogRage to limit Rails verbosity and collect request metrics into attributes.
- Backwards compatibility with ActiveSupport::TaggedLogging.
- Added support for key/value based tags in addition to primitive data types.
- Auto formatting of exception objects.
Via the command line:
gem install lumberyakOr inside of a Gemfile:
gem "lumberyak"Add an initializer to your Rails project:
config/initializers/lumberyak.rb
Rails.application.configure do
config.lumberyak.enabled = true
endRails.application.configure do
# Whether or not LumberYak should be enabled. Defaults to `false`.
config.lumberyak.enabled = true
# Whether or not LumberYak should enable an configure LogRage. This Gem tends
# to be quite opinionated so if you prefer Rails logging out of the box you may
# wish to disable this. Note that LogRage does require a specific Formatter to
# work with LumberYak. LumberYak will configure this for you if the following
# is true.
config.lumberyak.configure_lograge = true
# A list of: methods that the request object responds to, a Proc that accepts
# the request object, or something that responds to 'to_hash' or 'to_s'. Note
# that if you already have a `config.log_tags` in your application config that
# you do not need this setting. If both are set LumberYak will default to this
# setting.
config.lumberyak.log_tags = nil
endSince LumberYak is backwards compatible with ActiveSupport::TaggedLogging, any existing calls like the following will work:
# Logs: { "message": "Stuff", "tags": ["BCX"] }
Rails.logger.tagged("BCX") { Rails.logger.info "Stuff" }
# Logs: { "message": "Stuff", "tags": ["BCX", "Jason"] }
Rails.logger.tagged("BCX", "Jason") { Rails.logger.info "Stuff" }
# Logs: { "message": "Stuff", "tags": ["BCX", "Jason"] }
Rails.logger.tagged("BCX") { Rails.logger.tagged("Jason") { Rails.logger.info "Stuff" } }But with LumberYak enabled, you can now use hash values both for tags and log messages.
# Logs: { "message": "Stuff", "item_id": "BCX" }
Rails.logger.tagged({ item_id: "BCX" }) { Rails.logger.info "Stuff" }
# Logs: { "message": "Stuff", "item_id": "BCX", "user_name": "Jason" }
Rails.logger.tagged({ item_id: "BCX", user_name: "Jason"}) { Rails.logger.info "Stuff" }
# Logs: { "item_id": "BCX", "user_name": "Jason", "item_action": "Stuff" }"
Rails.logger.tagged({ item_id: "BCX", user_name: "Jason"}) { Rails.logger.info({ item_action: "Stuff" }) }LumberYak will also autoformat any exception objects that are logged.
def index
begin
i = 1 / 0
rescue Exception => e
Rails.logger.tagged({ forced_error: true }) { Rails.logger.error e }
end
end
# Will log the following:
# {
# "level":"ERROR",
# "type":"ZeroDivisionError",
# "message":"divided by 0",
# "backtrace":".....",
# "timestamp":"2017-04-13T23:51:37+00:00",
# "tags":[],
# "forced_error: true
# }The Rails TaggedLogger can optionally use a configuration setting named log_tags. This setting is a list that contains either strings for literal values, symbols naming functions on the request objects whose return value you'd wish to include, or a proc whose return value will be included. For instance, for the following setting:
config.log_tags = [
"my logs rock",
:uuid,
proc do |request|
request.session.id
end
]This would generate logs that look like:
[my logs rock] [29adec3c2] [39dab3f0] Processing by HomeController#index as HTML
However, we can rewrite this to use LumberYak's support for hashes to rewrite our tags:
config.log_tags = [
proc do |request|
{
my_logs_what: "my logs rock",
request_id: request.uuid,
session_id: request.session.id
}
end
]Then our logs will look like the following:
{
"my_logs_what": "my logs rock",
"request_id": "29adec3c2",
"session_id": "39dab3f0",
"message": "Processing by HomeController#index as HTML"
}