# LogStashLogger
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LogStashLogger extends Ruby's `Logger` class to log directly to
[Logstash](https://www.elastic.co/products/logstash).
It supports writing to various outputs in logstash JSON format. This is an improvement over
writing to a file or syslog since Logstash can receive the structured data directly.

## Features

* Can write directly to a logstash listener over a UDP or TCP/SSL connection.
* Can write to a file, Redis, Kafka, Kinesis, Firehose, a unix socket, syslog, stdout, or stderr.
* Logger can take a string message, a hash, a `LogStash::Event`, an object, or a JSON string as input.
* Events are automatically populated with message, timestamp, host, and severity.
* Writes in logstash JSON format, but supports other formats as well.
* Can write to multiple outputs.
* Log messages are buffered and automatically re-sent if there is a connection problem.
* Easily integrates with Rails via configuration.

## Installation

Add this line to your application's Gemfile:

    gem 'logstash-logger'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install logstash-logger

## Usage Examples

```ruby
require 'logstash-logger'

# Defaults to UDP on 0.0.0.0
logger = LogStashLogger.new(port: 5228)

# Specify host and type (UDP or TCP) explicitly
udp_logger = LogStashLogger.new(type: :udp, host: 'localhost', port: 5228)
tcp_logger = LogStashLogger.new(type: :tcp, host: 'localhost', port: 5229)

# Other types of loggers
file_logger = LogStashLogger.new(type: :file, path: 'log/development.log', sync: true)
unix_logger = LogStashLogger.new(type: :unix, path: '/tmp/sock')
syslog_logger = LogStashLogger.new(type: :syslog)
redis_logger = LogStashLogger.new(type: :redis)
kafka_logger = LogStashLogger.new(type: :kafka)
stdout_logger = LogStashLogger.new(type: :stdout)
stderr_logger = LogStashLogger.new(type: :stderr)
io_logger = LogStashLogger.new(type: :io, io: io)

# Use a different formatter
cee_logger = LogStashLogger.new(
  type: :tcp,
  host: 'logsene-receiver-syslog.sematext.com',
  port: 514,
  formatter: :cee_syslog
)

custom_formatted_logger = LogStashLogger.new(
  type: :redis,
  formatter: MyCustomFormatter
)

lambda_formatted_logger = LogStashLogger.new(
  type: :stdout,
  formatter: ->(severity, time, progname, msg) { "[#{progname}] #{msg}" }
)

ruby_default_formatter_logger = LogStashLogger.new(
  type: :file,
  path: 'log/development.log',
  formatter: ::Logger::Formatter
)

# Send messages to multiple outputs. Each output will have the same format.
# Syslog cannot be an output because it requires a separate logger.
multi_delegating_logger = LogStashLogger.new(
  type: :multi_delegator,
  outputs: [
    { type: :file, path: 'log/development.log' },
    { type: :udp, host: 'localhost', port: 5228 }
  ])

# Balance messages between several outputs.
# Works the same as multi delegator, but randomly chooses an output to send each message.
balancer_logger = LogStashLogger.new(
  type: :balancer,
  outputs: [
    { type: :udp, host: 'host1', port: 5228 },
    { type: :udp, host: 'host2', port: 5228 }
  ])

# Send messages to multiple loggers.
# Use this if you need to send different formats to different outputs.
# If you need to log to syslog, you must use this.
multi_logger = LogStashLogger.new(
  type: :multi_logger,
  outputs: [
    { type: :file, path: 'log/development.log', formatter: ::Logger::Formatter },
    { type: :tcp, host: 'localhost', port: 5228, formatter: :json }
  ])

# The following messages are written to UDP port 5228:

logger.info 'test'
# {"message":"test","@timestamp":"2014-05-22T09:37:19.204-07:00","@version":"1","severity":"INFO","host":"[hostname]"}

logger.error '{"message": "error"}'
# {"message":"error","@timestamp":"2014-05-22T10:10:55.877-07:00","@version":"1","severity":"ERROR","host":"[hostname]"}

logger.debug message: 'test', foo: 'bar'
# {"message":"test","foo":"bar","@timestamp":"2014-05-22T09:43:24.004-07:00","@version":"1","severity":"DEBUG","host":"[hostname]"}

logger.warn LogStash::Event.new(message: 'test', foo: 'bar')
# {"message":"test","foo":"bar","@timestamp":"2014-05-22T16:44:37.364Z","@version":"1","severity":"WARN","host":"[hostname]"}

# Tagged logging
logger.tagged('foo') { logger.fatal('bar') }
# {"message":"bar","@timestamp":"2014-05-26T20:35:14.685-07:00","@version":"1","severity":"FATAL","host":"[hostname]","tags":["foo"]}
```

## URI Configuration
You can use a URI to configure your logstash logger instead of a hash. This is useful in environments
such as Heroku where you may want to read configuration values from the environment. The URI scheme
is `type://host:port/path?key=value`. Some sample URI configurations are given below.

```
udp://localhost:5228
tcp://localhost:5229
unix:///tmp/socket
file:///path/to/file
redis://localhost:6379
kafka://localhost:9092
stdout:/
stderr:/
```

Pass the URI into your logstash logger like so:

```ruby
# Read the URI from an environment variable
logger = LogStashLogger.new(uri: ENV['LOGSTASH_URI'])
```

## Logstash Listener Configuration

In order for logstash to correctly receive and parse the events, you will need to
configure and run a listener that uses the `json_lines` codec. For example, to receive
events over UDP on port 5228:

```ruby
input {
  udp {
    host => "0.0.0.0"
    port => 5228
    codec => json_lines
  }
}
```

File and Redis inputs should use the `json` codec instead. For more information
read the [Logstash docs](https://www.elastic.co/guide/en/logstash/current/plugins-codecs-json_lines.html).

See the [samples](https://github.com/dwbutler/logstash-logger/tree/master/samples) directory for more configuration samples.

## SSL

If you are using TCP then there is the option of adding an SSL certificate to the options hash on initialize.

```ruby
LogStashLogger.new(type: :tcp, port: 5228, ssl_certificate: "/path/to/certificate.crt")
```

The SSL certificate and key can be generated using

    openssl req -x509 -batch -nodes -newkey rsa:2048 -keyout logstash.key -out logstash.crt

You can also enable SSL without a certificate:

```ruby
LogStashLogger.new(type: :tcp, port: 5228, ssl_enable: true)
```

Specify an SSL context to have more control over the behavior. For example,
set the verify mode:

```ruby
ctx = OpenSSL::SSL::SSLContext.new
ctx.set_params(verify_mode: OpenSSL::SSL::VERIFY_NONE)
LogStashLogger.new(type: :tcp, port: 5228, ssl_context: ctx)
```

The following Logstash configuration is required for SSL:

```ruby
input {
  tcp {
    host => "0.0.0.0"
    port => 5228
    codec => json_lines
    ssl_enable => true
    ssl_cert => "/path/to/certificate.crt"
    ssl_key => "/path/to/key.key"
  }
}
```

### Hostname Verification

Hostname verification is enabled by default. Without further configuration,
the hostname supplied to `:host` will be used to verify the server's certificate
identity.

If you don't pass an `:ssl_context` or pass a falsey value to the
`:verify_hostname` option, hostname verification will not occur.

#### Examples

**Verify the hostname from the `:host` option**

```ruby
ctx = OpenSSL::SSL::SSLContext.new
ctx.cert = '/path/to/cert.pem'
ctx.verify_mode = OpenSSL::SSL::VERIFY_PEER

LogStashLogger.new \
  type: :tcp,
  host: 'logstash.example.com'
  port: 5228,
  ssl_context: ctx
```

**Verify a hostname different from the `:host` option**

```ruby
LogStashLogger.new \
  type: :tcp,
  host: '1.2.3.4'
  port: 5228,
  ssl_context: ctx,
  verify_hostname: 'server.example.com'
```

**Explicitly disable hostname verification**

```ruby
LogStashLogger.new \
  type: :tcp,
  host: '1.2.3.4'
  port: 5228,
  ssl_context: ctx,
  verify_hostname: false
```

## Custom Log Fields

`LogStashLogger` by default will log a JSON object with the format below.

```json
{
  "message":"Some Message",
  "@timestamp":"2015-01-29T10:43:32.196-05:00",
  "@version":"1",
  "severity":"INFO",
  "host":"hostname"
}
```

Some applications may need to attach additional metadata to each message.
The `LogStash::Event` can be manipulated directly by specifying a `customize_event` block in the `LogStashLogger` configuration.

```ruby
config = LogStashLogger.configure do |config|
  config.customize_event do |event|
    event["other_field"] = "some_other_value"
  end
end
```

This configuration would result in the following output.

```json
{
    "message": "Some Message",
    "@timestamp": "2015-01-29T10:43:32.196-05:00",
    "@version": "1",
    "severity": "INFO",
    "host": "hostname",
    "other_field": "some_other_value"
}
```

This block has full access to the event, so you can remove fields, modify
existing fields, etc. For example, to remove the default timestamp:

```ruby
config = LogStashLogger.configure do |config|
  config.customize_event do |event|
    event.remove('@timestamp')
  end
end
```

You can also customize events on a per-logger basis by passing a callable object
(lambda or proc) to the `customize_event` option when creating a logger:

```ruby
LogStashLogger.new(customize_event: ->(event){ event['other_field'] = 'other_field' })
``` 

## Buffering / Automatic Retries

For devices that establish a connection to a remote service, log messages are buffered internally
and flushed in a background thread. If there is a connection problem, the
messages are held in the buffer and automatically resent until it is successful.
Outputs that support batch writing (Redis and Kafka) will write log messages in bulk from the
buffer. This functionality is implemented using a fork of
[Stud::Buffer](https://github.com/jordansissel/ruby-stud/blob/master/lib/stud/buffer.rb).
You can configure its behavior by passing the following options to LogStashLogger:

* :buffer_max_items - Max number of items to buffer before flushing. Defaults to 50.
* :buffer_max_interval - Max number of seconds to wait between flushes. Defaults to 5.
* :drop_messages_on_flush_error - Drop messages when there is a flush error. Defaults to false.
* :drop_messages_on_full_buffer - Drop messages when the buffer is full. Defaults to true.
* :sync - Flush buffer every time a message is received (blocking). Defaults to false.
* :buffer_flush_at_exit - Flush messages when exiting the program. Defaults to true.
* :buffer_logger - Logger to write buffer debug/error messages to. Defaults to none.

You can turn buffering off by setting `sync = true`.

Please be aware of the following caveats to this behavior:

 * It's possible for duplicate log messages to be sent when retrying. For outputs like Redis and
   Kafka that write in batches, the whole batch could get re-sent. If this is a problem, you
   can add a UUID field to each event to uniquely identify it. You can either do this
   in a `customize_event` block, or by using logstash's
   [UUID filter](https://www.elastic.co/guide/en/logstash/current/plugins-filters-uuid.html).
 * It's still possible to lose log messages. Ruby won't detect a TCP/UDP connection problem
   immediately. In my testing, it took Ruby about 4 seconds to notice the receiving end was down
   and start raising exceptions. Since logstash listeners over TCP/UDP do not acknowledge received
   messages, it's not possible to know which log messages to re-send.
 * When `sync` is turned off, Ruby may buffer data internally before writing to
   the IO device. This is why you may not see messages written immediately to a
   UDP or TCP socket, even though LogStashLogger's buffer is periodically flushed.

## Full Buffer

By default, messages are discarded when the buffer gets full. This can happen
if the output source is down for too long or log messages are being received
too quickly. If your application suddenly terminates (for example, by SIGKILL or a power outage),
the whole buffer will be lost.

You can make message loss less likely by increasing `buffer_max_items`
(so that more events can be held in the buffer), and decreasing `buffer_max_interval` (to wait
less time between flushes). This will increase memory pressure on your application as log messages
accumulate in the buffer, so make sure you have allocated enough memory to your process.

If you don't want to lose messages when the buffer gets full, you can set
`drop_messages_on_full_buffer = false`. Note that if the buffer gets full, any
incoming log message will block, which could be undesirable.

## Sync Mode

All logger outputs support a `sync` setting. This is analogous to the "sync mode" setting on Ruby IO
objects. When set to `true`, output is immediately flushed and is not buffered internally. Normally,
for devices that connect to a remote service, buffering is a good thing because
it improves performance and reduces the likelihood of errors affecting the program. For these devices,
`sync` defaults to `false`, and it is recommended to leave the default value.
You may want to turn sync mode on for testing, for example if you want to see
log messages immediately after they are written.

It is recommended to turn sync mode on for file and Unix socket outputs. This
ensures that log messages from different threads or proceses are written correctly on separate lines.

See [#44](https://github.com/dwbutler/logstash-logger/issues/44) for more details.

## Error Handling

If an exception occurs while writing a message to the device, the exception is
logged using an internal logger. By default, this logs to $stderr. You can
change the error logger by setting `LogStashLogger.configuration.default_error_logger`, or by passsing
your own logger object in the `:error_logger` configuration key when
instantiating a LogStashLogger.

## Logger Silencing

LogStashLogger provides support for Rails-style logger silencing. The
implementation was extracted from Rails, but has no dependencies, so it can be
used outside of a Rails app. The interface is the same as in Rails:

```ruby
logger.silence(temporary_level) do
  ...
end
```

## Rails Integration

Supports Rails 4 and 5.

By default, every Rails log message will be written to logstash in `LogStash::Event` JSON format.

For minimal, more-structured logstash events, try one of the following gems:

* [lograge](https://github.com/roidrage/lograge)
* [yarder](https://github.com/rurounijones/yarder)

Currently these gems output a JSON string, which LogStashLogger then parses.
Future versions of these gems could potentially have deeper integration with LogStashLogger
(e.g. by directly writing `LogStash::Event` objects).

### Rails Configuration

Add the following to your `config/environments/production.rb`:

#### Common Options

```ruby
# Optional, Rails sets the default to :info
config.log_level = :debug

# Optional, Rails 4 defaults to true in development and false in production
config.autoflush_log = true

# Optional, use a URI to configure. Useful on Heroku
config.logstash.uri = ENV['LOGSTASH_URI']

# Optional. Defaults to :json_lines. If there are multiple outputs,
# they will all share the same formatter.
config.logstash.formatter = :json_lines

# Optional, the logger to log writing errors to. Defaults to logging to $stderr
config.logstash.error_logger = Logger.new($stderr)

# Optional, max number of items to buffer before flushing. Defaults to 50
config.logstash.buffer_max_items = 50

# Optional, max number of seconds to wait between flushes. Defaults to 5
config.logstash.buffer_max_interval = 5

# Optional, drop message when a connection error occurs. Defaults to false
config.logstash.drop_messages_on_flush_error = false

# Optional, drop messages when the buffer is full. Defaults to true
config.logstash.drop_messages_on_full_buffer = true
```

#### UDP
```ruby
# Optional, defaults to '0.0.0.0'
config.logstash.host = 'localhost'

# Optional, defaults to :udp.
config.logstash.type = :udp

# Required, the port to connect to
config.logstash.port = 5228
```

#### TCP

```ruby
# Optional, defaults to '0.0.0.0'
config.logstash.host = 'localhost'

# Required, the port to connect to
config.logstash.port = 5228

# Required
config.logstash.type = :tcp

# Optional, enables SSL
config.logstash.ssl_enable = true
```

#### Unix Socket

```ruby
# Required
config.logstash.type = :unix

# Required
config.logstash.path = '/tmp/sock'
```

#### Syslog

If you're on Ruby 1.9, add `Syslog::Logger` v2 to your Gemfile:

    gem 'SyslogLogger', '2.0'

If you're on Ruby 2+, `Syslog::Logger` is already built into the standard library.

```ruby
# Required
config.logstash.type = :syslog

# Optional. Defaults to 'ruby'
config.logstash.program_name = 'MyApp'

# Optional default facility level. Only works in Ruby 2+
config.logstash.facility = Syslog::LOG_LOCAL0
```

#### Redis

Add the redis gem to your Gemfile:

    gem 'redis'

```ruby
# Required
config.logstash.type = :redis

# Optional, will default to the 'logstash' list
config.logstash.list = 'logstash'

# All other options are passed in to the Redis client
# Supported options include host, port, path, password, url
# Example:

# Optional, Redis will default to localhost
config.logstash.host = 'localhost'

# Optional, Redis will default to port 6379
config.logstash.port = 6379
```

#### Kafka

Add the poseidon gem to your Gemfile:

    gem 'poseidon'

```ruby
# Required
config.logstash.type = :kafka

# Optional, will default to the 'logstash' topic
config.logstash.path = 'logstash'

# Optional, will default to the 'logstash-logger' producer
config.logstash.producer = 'logstash-logger'

# Optional, will default to localhost:9092 host/port
config.logstash.hosts = ['localhost:9092']

# Optional, will default to 1s backoff
config.logstash.backoff = 1

```

#### Kinesis

Add the aws-sdk gem to your Gemfile:

    gem 'aws-sdk'

```ruby
# Required
config.logstash.type = :kinesis

# Optional, will default to the 'logstash' stream
config.logstash.stream = 'my-stream-name'

# Optional, will default to 'us-east-1'
config.logstash.aws_region = 'us-west-2'

# Optional, will default to the AWS_ACCESS_KEY_ID environment variable
config.logstash.aws_access_key_id = 'ASKASKHLD12341'

# Optional, will default to the AWS_SECRET_ACCESS_KEY environment variable
config.logstash.aws_secret_access_key = 'ASKASKHLD1234123412341234'

```

#### Firehose

Add the aws-sdk gem to your Gemfile:

    gem 'aws-sdk'

```ruby
# Required
config.logstash.type = :firehose

# Optional, will default to the 'logstash' delivery stream
config.logstash.stream = 'my-stream-name'

# Optional, will default to 'us-east-1'
config.logstash.aws_region = 'us-west-2'

# Optional, will default to the AWS_ACCESS_KEY_ID environment variable
config.logstash.aws_access_key_id = 'ASKASKHLD12341'

# Optional, will default to the AWS_SECRET_ACCESS_KEY environment variable
config.logstash.aws_secret_access_key = 'ASKASKHLD1234123412341234'

```

#### File

```ruby
# Required
config.logstash.type = :file

# Optional, defaults to Rails log path
config.logstash.path = 'log/production.log'
```

#### IO

```ruby
# Required
config.logstash.type = :io

# Required
config.logstash.io = io
```

#### Multi Delegator

```ruby
# Required
config.logstash.type = :multi_delegator

# Required
config.logstash.outputs = [
  {
    type: :file,
    path: 'log/production.log'
  },
  {
    type: :udp,
    port: 5228,
    host: 'localhost'
  }
]
```

#### Multi Logger

```ruby
# Required
config.logstash.type = :multi_logger

# Required. Each logger may have its own formatter.
config.logstash.outputs = [
  {
    type: :file,
    path: 'log/production.log',
    formatter: ::Logger::Formatter
  },
  {
    type: :udp,
    port: 5228,
    host: 'localhost'
  }
]
```

### Logging HTTP request data

In web applications, you can log data from HTTP requests (such as headers) using the
[RequestStore](https://github.com/steveklabnik/request_store) middleware. The following
example assumes Rails.

```ruby
# in Gemfile
gem 'request_store'
```

```ruby
# in application.rb
LogStashLogger.configure do |config|
  config.customize_event do |event|
    event["session_id"] = RequestStore.store[:load_balancer_session_id]
  end
end
```

```ruby
# in app/controllers/application_controller.rb
before_filter :track_load_balancer_session_id

def track_load_balancer_session_id
  RequestStore.store[:load_balancer_session_id] = request.headers["X-LOADBALANCER-SESSIONID"]
end
```

## Ruby Compatibility

Verified to work with:

* MRI Ruby 2.2 - 2.4
* JRuby 9.x
* Rubinius

Ruby versions < 2.2 are EOL'ed and no longer supported.

## What type of logger should I use?

It depends on your specific needs, but most applications should use the default (UDP). Here are the advantages and
disadvantages of each type:

* UDP is faster than TCP because it's asynchronous (fire-and-forget). However, this means that log messages could get dropped.
  This is okay for many applications.
* TCP verifies that every message has been received via two-way communication. It also supports SSL for secure transmission
  of log messages over a network. This could slow your app down to a crawl if the TCP listener is under heavy load.
* A file is simple to use, but you will have to worry about log rotation and running out of disk space.
* Writing to a Unix socket is faster than writing to a TCP or UDP port, but only works locally.
* Writing to Redis is good for distributed setups that generate tons of logs. However, you will have another moving part and
  have to worry about Redis running out of memory.
* Writing to stdout is only recommended for debugging purposes.

For a more detailed discussion of UDP vs TCP, I recommend reading this article:
[UDP vs. TCP](http://gafferongames.com/networking-for-game-programmers/udp-vs-tcp/)

## Troubleshooting

### Logstash never receives any logs
If you are using a device backed by a Ruby IO object (such as a file, UDP socket, or TCP socket), please be aware that Ruby
keeps its own internal buffer. Despite the fact that LogStashLogger buffers
messages and flushes them periodically, the data written to the IO object can
be buffered by Ruby internally indefinitely, and may not even write until the
program terminates. If this bothers you or you need to see log messages
immediately, your only recourse is to set the `sync: true` option.

### JSON::GeneratorError
Your application is probably attempting to log data that is not encoded in a valid way. When this happens, Ruby's
standard JSON library will raise an exception. You may be able to overcome this by swapping out a different JSON encoder
such as Oj. Use the [oj_mimic_json](https://github.com/ohler55/oj_mimic_json) gem to use Oj for JSON generation.

### No logs getting sent on Heroku
Heroku recommends installing the [rails_12factor](https://github.com/heroku/rails_12factor) so that logs get sent to STDOUT.
Unfortunately, this overrides LogStashLogger, preventing logs from being sent to their configured destination. The solution
is to remove `rails_12factor` from your Gemfile.

### Logging eventually stops in production
This is most likely not a problem with LogStashLogger, but rather a different gem changing the log level of `Rails.logger`.
This is especially likely if you're using a threaded server such as Puma, since gems often change the log level of
`Rails.logger` in a non thread-safe way. See [#17](https://github.com/dwbutler/logstash-logger/issues/17) for more information.

### Sometimes two lines of JSON log messages get sent as one message
If you're using UDP output and writing to a logstash listener, you are most likely encountering a bug in the UDP implementation
of the logstash listener. There is no known fix at this time. See [#43](https://github.com/dwbutler/logstash-logger/issues/43)
for more information.

### Errno::EMSGSIZE - Message too long
A known drawback of using TCP or UDP is the 65535 byte limit on total message size. To workaround
this issue, you will have to truncate the message by setting the max message size:

```ruby
LogStashLogger.configure do |config|
  config.max_message_size = 2000
end
```

This will truncate only the `message` field of the LogStash Event. So make sure
you set the max message size significantly less than 65535 bytes to make room
for other fields.

## Breaking changes

### Version 0.25+

Rails 3.2, MRI Ruby < 2.2, and JRuby 1.7 are no longer supported, since they have been
EOL'ed. If you are on an older version of Ruby, you will need to use 0.24 or below.

### Version 0.5+
 * The `source` event key has been replaced with `host` to better match the latest logstash.
 * The `(host, port, type)` constructor has been deprecated in favor of an options hash constructor.

### Version 0.4+
`LogStash::Event` uses the v1 format starting version 1.2+. If you're using the v1, you'll need to install
LogStashLogger version 0.4+. This is not backwards compatible with the old `LogStash::Event` v1.1.5, which uses
the v0 format.

### Version 0.3+
Earlier versions of this gem (<= 0.2.1) only implemented a TCP connection.
Newer versions (>= 0.3) also implement UDP, and use that as the new default.
Please be aware if you are using the default constructor and still require TCP, you should add an additional argument:

```ruby
# Now defaults to UDP instead of TCP
logger = LogStashLogger.new('localhost', 5228)
# Explicitly specify TCP instead of UDP
logger = LogStashLogger.new('localhost', 5228, :tcp)
```

## Contributors
* [David Butler](https://github.com/dwbutler)
* [pctj101](https://github.com/pctj101)
* [Gary Rennie](https://github.com/Gazler)
* [Nick Ethier](https://github.com/nickethier)
* [Arron Mabrey](https://github.com/arronmabrey)
* [Jan Schulte](https://github.com/schultyy)
* [Kurt Preston](https://github.com/KurtPreston)
* [Chris Blatchley](https://github.com/chrisblatchley)
* [Felix Bechstein](https://github.com/felixb)
* [Vadim Kazakov](https://github.com/yads)
* [Anil Rhemtulla](https://github.com/AnilRh)
* [Nikita Vorobei](https://github.com/Nikita-V)
* [fireboy1919](https://github.com/fireboy1919)
* [Mike Gunderloy](https://github.com/ffmike)
* [Vitaly Gorodetsky](https://github.com/vitalis)
* [Courtland Caldwell](https://github.com/caldwecr)
* [Bibek Shrestha](https://github.com/bibstha)
* [Alex Ianus](https://github.com/aianus)
* [Craig Read](https://github.com/Catharz)
* [glaszig](https://github.com/glaszig)
* [Bin Lan](https://github.com/lanxx019)
* [Joao Fernandes](https://github.com/jcmfernandes)
* [CoolElvis](https://github.com/coolelvis)
* [Sergey Pyankov](https://github.com/esergion)

## Contributing

1. Fork it
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 new Pull Request