View service logs

Docker Cloud grants you access to the logs your application writes to stdout. An internal service multiplexes all the logs from all the containers of a service into a single stream. To see a service’s logs run the docker-cloud service logs command with the name of the service.

If we run docker-cloud service logs web, you’ll see logs for both web-1 and web-2, like the example below.

$ docker-cloud service logs web
[web-1] 2015-01-13T22:45:37.250431077Z  * Running on http://0.0.0.0:80/
[web-1] 2015-01-07T17:20:19.076174813Z 83.50.33.64 - - [07/Jan/2015 17:20:19] "GET / HTTP/1.1" 200 -
[web-1] 2015-01-07T17:20:34.209098162Z 83.50.33.64 - - [07/Jan/2015 17:20:34] "GET / HTTP/1.1" 200 -
[web-1] 2015-01-07T18:46:07.116759956Z 83.50.33.64 - - [07/Jan/2015 18:46:07] "GET / HTTP/1.1" 200 -
[web-2] 2015-01-07T18:48:24.550419508Z  * Running on http://0.0.0.0:5000/
[web-2] 2015-01-07T18:48:37.116759956Z 83.50.33.64 - - [07/Jan/2015 18:48:37] "GET / HTTP/1.1" 200 -

To see a specific container’s logs, use the container logs and the specific container’s name. To learn more about service and container hostnames, see Service Discovery.

$ docker-cloud container logs web-1
2015-01-07T17:18:24.550419508Z  * Running on http://0.0.0.0:80/
2015-01-07T17:20:19.076174813Z 83.50.33.64 - - [07/Jan/2015 17:20:19] "GET / HTTP/1.1" 200 -
2015-01-07T17:20:34.209098162Z 83.50.33.64 - - [07/Jan/2015 17:20:34] "GET / HTTP/1.1" 200 -
2015-01-07T18:46:07.116759956Z 83.50.33.64 - - [07/Jan/2015 18:46:07] "GET / HTTP/1.1" 200 -

Visit your application using curl or your browser again. Run the service logs web command again, and you will see another log message for your visit.

What’s Next?

Now, let’s explore how to Load balance the service.