Logging

tsuru aggregates stdout and stderr from every application process making easier to troubleshoot problems. To use the log make sure that your application is sending the log to stdout and stderr.

Watch your logs

To see the logs for your application. You can use the tsuru app-log command:

$ tsuru app-log -a <appname>
2014-12-11 16:36:17 -0200 [tsuru][api]:  ---> Removed route from unit 1d913e0910
2014-12-11 16:36:17 -0200 [tsuru][api]: ---- Removing 1 old unit ----
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Starting gunicorn 18.0
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Listening at: http://0.0.0.0:8100 (51)
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Using worker: sync
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Booting worker with pid: 60
2014-12-11 16:36:28 -0200 [tsuru][api]:  ---> Removed old unit 1/1

By default is showed the last ten log lines. If you want see more lines, you can use the -l/–lines parameter:

$ tsuru app-log -a <appname> --lines 100

Filtering

You can filter logs by unit and by source.

To filter by unit you should use -u/–unit parameter:

$ tsuru app-log -a <appname> --unit 11f863b2c14b
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Starting gunicorn 18.0
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Listening at: http://0.0.0.0:8100 (51)
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Using worker: sync

See also

To get the unit id you can use the tsuru app-info -a <appname> command.

The log can be sent by your process or by tsuru api. To filter by source you should use -s/–source parameter:

$ tsuru app-log -a <appname> --source app
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Starting gunicorn 18.0
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Listening at: http://0.0.0.0:8100 (51)
2014-12-11 16:36:22 -0200 [app][11f863b2c14b]: Using worker: sync

$ tsuru app-log -a <appname> --source tsuru
2014-12-11 16:36:17 -0200 [tsuru][api]:  ---> Removed route from unit 1d913e0910
2014-12-11 16:36:17 -0200 [tsuru][api]: ---- Removing 1 old unit ----

Realtime logging

tsuru app-log has a -f/–follow option that causes the log to not stop and wait for the new log data. With this option you can see in real time the behaviour of your application that is useful to debug problems:

$ tsuru app-log -a <appname> --follow

You can close the session pressing Ctrl-C.

Limitations

The tsuru native log system is designed to be fast and show the recent log of your application. The tsuru log doesn’t store all log entries for your application.

If you want to store and see all log entries you should use an external log aggregator.

Using an external log aggregator

You can also send the log to an external log aggregator. To do this, tsuru uses the syslog protocol.

To use syslog you should set these variables in your application:

TSURU_SYSLOG_SERVER
TSURU_SYSLOG_PORT (probably 514)
TSURU_SYSLOG_FACILITY (something like local0)
TSURU_SYSLOG_SOCKET (tcp or udp)

You can use the tsuru env-set to set these enviroment variables in your application:

$ tsuru env-set -a myapp TSURU_SYSLOG_SERVER=myserver.com TSURU_SYSLOG_PORT=514 TSURU_SYSLOG_FACILITY=local0 TSURU_SYSLOG_SOCKET=tcp