〇直近のログを出力

logs <app> [-h] [-t] [-n num] [-q] [-p process]
 
-h            : 
-t, --tail    : 出力内容をリアルタイムで更新。
-n, --num     : 画面に出力する行数。
-q, --quiet   : RAWデータを出力。（文字色、時刻、アプリケーション名は出力しない）
-p, --ps      : 画面に出力するプロセス。

〇最後に失敗したデプロイのログを出力

logs:failed [<app>]

〇直近のログを出力

dokku logs ruby-getting-started

2019-09-13T19:37:32.710348749Z app[web.1]: [8] Puma starting in cluster mode...
2019-09-13T19:37:32.710619587Z app[web.1]: [8] * Version 3.11.2 (ruby 2.4.4-p296), codename: Love Song
2019-09-13T19:37:32.710775099Z app[web.1]: [8] * Min threads: 5, max threads: 5
2019-09-13T19:37:32.710928898Z app[web.1]: [8] * Environment: production
2019-09-13T19:37:32.711078665Z app[web.1]: [8] * Process workers: 2
2019-09-13T19:37:32.711351229Z app[web.1]: [8] * Preloading application
2019-09-13T19:37:40.392532902Z app[web.1]: [8] * Listening on tcp://0.0.0.0:5000
2019-09-13T19:37:40.400286865Z app[web.1]: [8] Use Ctrl-C to stop
2019-09-13T19:37:40.408249283Z app[web.1]: [8] - Worker 0 (pid: 157) booted, phase: 0
2019-09-13T19:37:40.412525678Z app[web.1]: [8] - Worker 1 (pid: 169) booted, phase: 0
2019-09-16T05:23:42.521275188Z app[web.1]: [8] ! Terminating timed out worker: 157
2019-09-16T05:23:43.609182402Z app[web.1]: [8] - Worker 0 (pid: 185) booted, phase: 0

〇最後に失敗したデプロイのログを出力

dokku logs:failed ruby-getting-started

=====> ruby-getting-started failed deploy logs
 !     No failed containers found