Logamaton

Logfile automation for JSON logs.

var logamaton = require('logamaton');

var entries = logamaton({
  readStream: fs.createReadStream('./logs.json'),
});

entries
  .filter(logamaton.filters.all())
  .filter(logamaton.filters.after({
    start: new Date('2014-01-01')
  }))
  .filter(logamaton.filters.has('err'))
  .report(function (results) {
    console.log(results);
  });

Installation

$ npm install logamaton

Filters

Determine whether a given entry from a log is interesting or not. All filters are instrumented to capture a count of all log entries they receive and a copy of all entries they match. They may be defined either as arguments to logamaton:

var filters = [
  logamaton.filters.all(),
  logamaton.filters.after({ start: new Date('2014-03-18T02:14:39.151Z') }),
  logamaton.filters.has('err'),
  logamaton.filters.where({ level: 40 })
];

logamaton({
  readStream: process.stdin,
  filters: filters
});

Or by chaining with filter:

logamaton({ readStream: process.stdin });
  .filter(logamaton.filters.all())
  .filter(logamaton.filters.after({ start: new Date('2014-03-18T02:14:39.151Z') }));

Custom Filters

Custom filters may be built using logamaton.instrument(name, iter):

var fzbz = logamaton.instrument('fzbz', function (data, callback) {
  data.fizz = 'buzz';
  callback(null, data);
});

Reporters

Reporters inspect filter metrics to summarize the contents of the log. They may be defined either as arguments to logamaton:

function aReporter (results) {
  console.log(results.total);
}

logamaton({
  readStream: process.stdin,
  filters: filters,
  reports: [aReporter]
});

Or by chaining with report:

logamaton({ readStream: process.stdin })
  .report(function (results) {
    console.log(results.total);
  })

Reports for an individual function may also be recovered from a specific filter by calling results() on the filter.

var after = logamaton.filters.after({
  start: new Date('2014-03-18T02:14:39.151Z')
});

logamaton({ readStream: process.stdin })
  .filter(after)
  .report(function () {
    console.log(after.results().matches);
  });

TODO

More filtering, more reporting, more analytics. Test coverage. Benchmarking.

Contributing

Have something to add? Contributions are enormously welcome!

Fork this repo
Update the spec and implement the change
Submit a pull request

License

Logamaton is released under the terms of the JSON license

rjz/logamaton