dalee-logger

Great for Docker/Kubernetes environments.

Currently in production testing phase.

Key features:

• Minimal configuration required
• Bundled framework support:
  • hapi.js >= v15.2.0
  • express.js >= v4.0.0
• General uncaughtException and unhandledRejection handling (process will be terminated)
• Console writer (enabled by default)
• Syslog RFC3164 udp4 writer

Usage

npm i dalee-logger --save

Configuration

Global configuration options:

• facility - facility, default value: 1 (USER) (syslog parameter)
• severity - severity for events logged with log method, default value: debug
• hostname - hostname (syslog parameter), default value: os.hostname()
• app - application name (syslog parameter), default value: path.basename(process.title)
• logger_level - output event level, possible values are:
  • emerg
  • alert
  • critical
  • error
  • warning
  • notice
  • info
  • debug

logger_level also can be set via environment variable LOGGER_LEVEL

Adapter configuration

Console

• enabled - true/false, should console be silent or not, default is true

Sample output:

[2016-11-26 13:52:45.2342] debug: Hello world

Syslog

• host - valid fqdn or ip address of Syslog/Logstash daemon
• port - udp4 port number

Sample output (udp4 packet):

<0>2016-11-26 23:23:23.4554 localhost app: hello world

Standalone

import Logger from 'dalee-logger';

Logger.setParameters({ app: 'node' });

Logger.addAdapter(Logger.Console, {});
Logger.addAdapter(Logger.Syslog, {
    'host': 'example.com',
    'port': 514
});

Logger.debug('Will write to console and send UDP syslog packet');

hapi.js

hapi >= 17.0.0

Register as plugin in manifest.js:

plugin: {
  plugin: 'dalee-logger/hapi-17',
  options: {
    app: 'node-daemon',
    hostname: 'example.com',
    console: {
      enabled: true
    },
    syslog: {
      host: 'example.com',
      port: 514
    }
  }
}

hapi >= 15.2.0 < 17.0.0

Register as plugin in manifest.js:

plugin: {
  register: 'dalee-logger/hapi',
  options: {
    app: 'node-daemon',
    hostname: 'example.com',
    console: {
      enabled: true
    },
    syslog: {
      host: 'example.com',
      port: 514
    }
  }
}

express.js

Register as express middleware:

import express from 'express';
import expressLogger from 'dalee-logger/express';

const app = express();
const logger = expressLogger({
  app: 'node-daemon',
  hostname: 'example.com',
  console: {
    enabled: true
  },
  syslog: {
    host: 'example.com',
    port: 514
  }
});

app.use(logger);

app.get('/', function(req,res) {
    req.log('notice', 'The next message will be error');
    undefined.error = 'Force error';
});

app.use(logger.errorLogger);

app.listen(80, () => {
    logger.log('debug', 'server started');
});

Sample Logstash configuration

Check out our ELK-playground project

• Logstash will listen on port 5000 for udp packets
• Successfully parsed message will go into index named logstash-{syslog_program}
• Every unparsed line will go to index named logstash-error
• Logstash will write to Elastic on localhost:9200

input {
    udp {
        port => 5000
        type => syslog
    }
}

filter {
    grok {
      match => { "message" => "<%{POSINT:syslog_pri}>%{SYSLOGTIMESTAMP:syslog_timestamp} %{SYSLOGHOST:syslog_hostname} %{DATA:syslog_program}(?:\[%{POSINT:syslog_pid}\])?: %{GREEDYDATA:syslog_message}" }
      add_field => [ "received_at", "%{@timestamp}" ]
      add_field => [ "index_type", "%{syslog_program}" ]
    }

    date {
      match => [ "syslog_timestamp", "MMM d HH:mm:ss.SSS" ]
      locale => "en"
      timezone => "Europe/Moscow"
      target => "@timestamp"
    }

    syslog_pri {
    }

    # every unparsed line will go to logstash-error index
    if "_grokparsefailure" in [tags] {
        mutate {
            add_field => [ "index_type", "error" ]
        }
    }
}

output {
    elasticsearch {
        # flush_size = 1 set only for debugging purposes, should be > 1 on production
        flush_size => 1
        hosts => ["localhost:9200"]
        index => "logstash-%{index_type}"
    }
    stdout {
        # this should be disabled in production environment
        codec => rubydebug
    }
}

License

Software licensed under the MIT License.