Sw::Logger

This Logger is used in SayWay's applications for context rich logging. That way we can easily extract metrics and analyze our JSON logs.

Installation

Add this line to your application's Gemfile:

gem 'sw-logger'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install sw-logger

Usage

# get an instance of the logger that logs to standard output
logger = Sw.logger(STDOUT)

# it follows the normal logger interface
logger.info("Hello World")
# => I, [2020-01-31T11:00:08.577103 #29982]  INFO -- : Hello World

# it can be tagged
logger.tagged("MyApp") { |l| l.debug("is bug free!") }
# => D, [2020-01-31T11:00:35.585755 #29982] DEBUG -- : [MyApp] is bug free!

# you can provide context as a hash
context = {
  tenant: "FooCorp",
  revision: "4e0b166"
}
logger.with_context(context) { |l| l.info("Where am I?") }
# => I, [2020-01-31T11:00:58.063731 #29982]  INFO -- : [tenant=FooCorp] [revision=4e0b166] Where am I?

# nested context is just dumped as is for non-json formatters
logger.with_context(foo: { bar: 42 }) { |l| l.info("Use JSON instead!") }
# => I, [2020-01-31T11:01:57.894093 #29982]  INFO -- : [bar={:foo=>42}] Use JSON instead!

# you can go batshit crazy when using a json logger, anything that can be dumped to json is fair game
Sw.json_logger(STDOUT).with_context(foo: { bar: 42 }) { |l| l.info("Oooh, yeah!") }
# => {"bar":{"foo":42},"severity":"INFO","timestamp":"2020-01-31T11:27:34.848643","message":"Oooh, yeah!"}

# you can also chain tags and context,
# you also don't need to open a block for a single tagged / context enriched statement
logger.tagged("MyApp", "MyDomain").with_context(tenant: 42).info("Tags & Context apply only for this call.")
# => I, [2020-01-31T11:45:11.348817 #35215]  INFO -- : [MyApp] [MyDomain] [tenant=42] Tags & Context apply only for this call.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/say-way/sw-logger.

License

The gem is available as open source under the terms of the MIT License.