grape-middleware-logger/README.md

# A logger for [Grape](https://github.com/ruby-grape/grape) apps
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Logs:
  * Request path
  * Parameters
  * Endpoint class name and handler
  * Response status
  * Duration of the request
  * Exceptions
  * Error responses from `error!`

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'grape', '>= 0.17'
gem 'grape-middleware-logger'
```

## Usage
```ruby
require 'grape'
require 'grape/middleware/logger'

class API < Grape::API
  # @note Make sure this is above your first +mount+
  insert_after Grape::Middleware::Formatter, Grape::Middleware::Logger
end
```

Server requests will be logged to STDOUT by default.

## Example output
GET
```
Started GET "/v1/reports/101" at 2015-12-11 15:40:51 -0800
Processing by ReportsAPI/reports/:id
  Parameters: {"id"=>"101"}
Completed 200 in 6.29ms
```
POST
```
Started POST "/v1/reports" at 2015-12-11 15:42:33 -0800
Processing by ReportsAPI/reports
  Parameters: {"name"=>"foo", "password"=>"[FILTERED]"}
  Error: {:error=>"undefined something something bad", :detail=>"Whoops"}
Completed 422 in 6.29ms
```

## Customization

The middleware logger can be customized with the following options:

* The `:logger` option can be any object that responds to `.info(String)`
* The `:condensed` option configures the log output to be on one line instead of multiple.  It accepts `true` or `false`.   The default configuration is `false`
* The `:filter` option can be any object that responds to `.filter(Hash)` and returns a hash.
* The `:headers` option can be either `:all` or array of strings.
    + If `:all`, all request headers will be output.
    + If array, output will be filtered by names in the array. (case-insensitive)

For example:

```ruby
insert_after Grape::Middleware::Formatter, Grape::Middleware::Logger, {
  logger: Logger.new(STDERR),
  condensed: true,
  filter: Class.new { def filter(opts) opts.reject { |k, _| k.to_s == 'password' } end }.new,
  headers: %w(version cache-control)
}
```

## Using Rails?
`Rails.logger` and `Rails.application.config.filter_parameters` will be used automatically as the default logger and
param filterer, respectively. This behavior can be overridden by passing the `:logger` or
`:filter` option when mounting.

You may want to disable Rails logging for API endpoints, so that the logging doesn't double-up. You can achieve this
by switching around some middleware. For example:

```ruby
# config/application.rb
config.middleware.swap 'Rails::Rack::Logger', 'SelectiveLogger'

# config/initializers/selective_logger.rb
class SelectiveLogger
  def initialize(app)
    @app = app
  end

  def call(env)
    if env['PATH_INFO'] =~ %r{^/api}
      @app.call(env)
    else
      Rails::Rack::Logger.new(@app).call(env)
    end
  end
end
```

## Rack

If you're using the `rackup` command to run your server in development, pass the `-q` flag to silence the default rack logger.

## Credits

Big thanks to jadent's question/answer on [stackoverflow](http://stackoverflow.com/questions/25048163/grape-using-error-and-grapemiddleware-after-callback)
for easily logging error responses. Borrowed some motivation from the [grape_logging](https://github.com/aserafin/grape_logging) gem
and would love to see these two consolidated at some point.

## Contributing

1. Fork it ( https://github.com/ridiculous/grape-middleware-logger/fork )
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create a new Pull Request