DockerCLI/docs/reference/commandline/logs.md

title	description	keywords
logs	The logs command description and usage	logs, retrieve, docker

logs

Usage:  docker logs [OPTIONS] CONTAINER

Fetch the logs of a container

Options:
      --details        Show extra details provided to logs
  -f, --follow         Follow log output
      --help           Print usage
      --since string   Show logs since timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)
      --until string   Show logs before timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)
  -n, --tail string    Number of lines to show from the end of the logs (default "all")
  -t, --timestamps     Show timestamps

Description

The docker logs command batch-retrieves logs present at the time of execution.

Note

This command is only functional for containers that are started with the json-file or journald logging driver.

For more information about selecting and configuring logging drivers, refer to Configure logging drivers.

The docker logs --follow command will continue streaming the new output from the container's STDOUT and STDERR.

Passing a negative number or a non-integer to --tail is invalid and the value is set to all in that case.

The docker logs --timestamps command will add an RFC3339Nano timestamp , for example 2014-09-16T06:17:46.000000000Z, to each log entry. To ensure that the timestamps are aligned the nano-second part of the timestamp will be padded with zero when necessary.

The docker logs --details command will add on extra attributes, such as environment variables and labels, provided to --log-opt when creating the container.

The --since option shows only the container logs generated after a given date. You can specify the date as an RFC 3339 date, a UNIX timestamp, or a Go duration string (e.g. 1m30s, 3h). Besides RFC3339 date format you may also use RFC3339Nano, 2006-01-02T15:04:05, 2006-01-02T15:04:05.999999999, 2006-01-02Z07:00, and 2006-01-02. The local timezone on the client will be used if you do not provide either a Z or a +-00:00 timezone offset at the end of the timestamp. When providing Unix timestamps enter seconds[.nanoseconds], where seconds is the number of seconds that have elapsed since January 1, 1970 (midnight UTC/GMT), not counting leap seconds (aka Unix epoch or Unix time), and the optional .nanoseconds field is a fraction of a second no more than nine digits long. You can combine the --since option with either or both of the --follow or --tail options.

Examples

Retrieve logs until a specific point in time

In order to retrieve logs before a specific point in time, run:

$ docker run --name test -d busybox sh -c "while true; do $(echo date); sleep 1; done"
$ date
Tue 14 Nov 2017 16:40:00 CET
$ docker logs -f --until=2s test
Tue 14 Nov 2017 16:40:00 CET
Tue 14 Nov 2017 16:40:01 CET
Tue 14 Nov 2017 16:40:02 CET