Sapience

Hasslefree autoconfiguration for logging, metrics and exception collection.

Background

We searched long and hard for a way to control our logging, error collection and metrics from a single place. The closest we could find that does everything we need is Semantic Logger. Unfortunately we couldn't find a good way to control the settings for our projects and would have had to spread our configuration over different initializers and rails configurations for each project. There was no easy way to gain that top level control over the configuration.

This project aims to make it easier to centralize the configuration of these three areas by handling the configuration a little differently.

We have taken a hug deal of inspiration from the amazing Semantic Logger and implemented something similar to Rubocop for handling and overriding how to find configuration. If you want some inspiration for how we do something similar for our projects for Rubocop check: Reevoocop.

Setup

First of all we need to require the right file for the project. There are currently two frameworks supported (rails and grape).

Rails

gem "sapience-rb", require: "sapience/rails"

Grape

gem "sapience-rb", require: "sapience/grape"

Configuration

The sapience configuration can be controlled by a config/sapience.yml file or if you like us have many projects that use the same configuration you can create your own gem with a shared config. Have a look at reevoo/reevoo_sapience-rb

Sapience.configure do |config|
  config.default_level   = :info
  config.backtrace_level = :error
  config.application     = "my-app"
  config.appenders       = [
    { file: { io: STDOUT, formatter: :color } },
    { sentry: { dsn: "https://username:password@app.getsentry.com/00000" } },
    { datadog: { url: "udp://localhost:8125" } },
  ]
end

Sapience provides a default configuration that will be used unless another file or configuration is specified. You can provide a custom

---
default:
  log_level: info
  appenders:
    - file:
        io: STDOUT
        formatter: color

test:
  log_level: warn
  appenders:
    - file:
        file_name: log/test.log
        formatter: color

development:
  log_level: debug
  appenders:
    - file:
        file_name: log/development.log
        formatter: color

production:
  log_level: warn
  appenders:
    - file:
        file_name: log/production.log
        formatter: json

Appenders

One of the things that did not suite us so well with the Semantic Logger approach was that they made a distinction between metrics and appenders. In our view anything that should potentially log something somewhere should be treated as an appender.

There are a number of appenders that all listen to different events and act on its data. It is possible to specify the level and backtrace_level for each appender by providing (example) level: :error to the add_appender method.

File

File appenders are basically a log stream. You can add as many file appenders as you like logging to different locations.

Sapience.add_appender(:file, file_name: "log/sapience.log", formatter: :json)
Sapience.add_appender(:file, io: STDOUT, formatter: :color, level: :trace)

Sentry

The sentry appender handles sending errors to sentry. It's backtrace and log level can be configured by for instance level: :info and backtrace_level: :debug. The level configuration tells sentry to log starting at that level while the backtrace_level tells sentry to only collect backtrace starting at that level.

Sapience.add_appender(
  :sentry, 
  dsn: "https://username:password@app.getsentry.com/00000", 
  level: :error, 
  backtrace_level: :error
)

Datadog

Datadog is a slightly modified version of statsd. On top of the standard statsd API it has support for events.

Sapience.add_appender(:datadog, url: "udp://localhost:8125")

The appender will then be listening to anything that is logged with a metric: "company/project/metric-name" key. Details about the API can be found in dogstatsd-ruby.

The appender can also be used directly through: Sapience.metrix

metrix = Sapience.metrix
metrix.timing("company/project/metric-name", 100)
metrix.increment("company/project/metric-name", 10)
metrix.decrement("company/project/metric-name", 5)
metrix.histogram("company/project/metric-name", 2_500)
metrix.gauge("company/project/metric-name", 1_000, {})
metrix.event("company/project/metric-name", "description about event", {})
metrix.batch do 
  metrix.event("company/project/metric-name", "description about event", {})
  metrix.increment("company/project/another-metric-name", 2)
end

Wrapper

The wrapper is useful when you already have a logger you want to use but want to use Sapience. The wrapper appender will when called use the logger provided to store the log data.

Sapience.add_appender(:wrapper, logger: Logger.new(STDOUT))

Formatters

Formatters can be specified by using the key formatter: :camelized_formatter_name. Note: Only the File appender supports custom formatters.

Color

formatter: :color - gives colorized output. Useful for test and development environments.

Default

formatter: :default - logs a string. Inspired by how access logs for Nginx are logged.

JSON

formatter: :json - logs are saved as a single line json. Useful for production like environments.

RAW

formatter: :raw - logs are saved as a single line ruby hash. Useful for production like environments and is used internally for the Sentry appender.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/reevoo/sapience. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

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