docker-logs-localtime - Replace all UTC dates in docker logs output to local dates in pipe

docker-logs-localtime

#!/usr/bin/env node
// replace all UTC dates to local dates in pipe
// usage: docker logs -t container_name | docker-logs-localtime

// install:	
// curl https://gist.githubusercontent.com/popstas/ffcf282492fd78389d1df2ab7f31052a/raw/505cdf97c6a1edbb10c3b2b64e1836e0627b87a0/docker-logs-localtime > /usr/local/bin/docker-logs-localtime && chmod +x /usr/local/bin/docker-logs-localtime	

// alternative: https://github.com/HuangYingNing/docker-logs-localtime

const pad = d => (d > 9 ? d : '0' + d);

Date.prototype.outDateTime = function() {
  return (
    [this.getFullYear(), pad(this.getMonth() + 1), pad(this.getDate())].join('-') +
    ' ' +
    [pad(this.getHours()), pad(this.getMinutes()), pad(this.getSeconds())].join(':')
  );
};

process.stdin.resume();
process.stdin.setEncoding('utf8');
process.stdin.on('data', function(data) {
  data = data.replace(/\.\d+Z /g, ' ');
  const match = data.match(/\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}/g);
  if (match) {
    match.forEach(dateUtc => {
      const d = new Date(dateUtc);
      const offset = new Date().getTimezoneOffset() * 60000;
      const dateLocal = new Date(d.getTime() - offset).outDateTime();
      data = data.replace(dateUtc, dateLocal);
    });
  }
  process.stdout.write(data);
});

It works for echo command, but not for docker logs. What could be the problem I'm having?

It works for echo command, but not for docker logs. What could be the problem I'm having?

Fixed! I found that it is because the output of docker logs in my case is stderr(not stdout). So my workaround is redirecting the stderr to stdout by adding 2>&1 at the tail of docker logs command. For example:

$ docker logs -t -n 1 doccano 2>&1 | ./docker-logs-localtime
2022-03-02 14:42:21 django.db.utils.IntegrityError: UNIQUE constraint failed

It works for me ( Docker version 20.10.13, build a224086 @ WSL2 Ubuntu 20.04)
Thanks for the good work 👍 💻

Thank you very much!

Fork with timezone offset:
https://gist.github.com/anton-x-t/859a69d0426ed1e4040660f57229c76c