How to write to stdout with Ruby on Bluemix?

Question

I am using Bluemix Ruby buildpack out of the box. I add some puts lines in my main *.rb file but nothing appears when tailing logs:

cf logs myapp

Searching the docs, I found this post at developerWorks where it is recommended to set runtime into development mode.

I have tried with:

cf set-env myapp RAILS_ENV development

and also adding to the code:

ENV['RAILS_ENV'] = 'development'

but nothing appears in the logs.

Also tried Sinatra options (after changing the code) with same results:

set :environment, :development
set :logging, true

An interesting thing, is that if I stop the app, then all my puts appears after the stacktrace of the FATAL SignalException: SIGTERM error. It seems like a buffer flush contention or anything like that?

Any advice? Thanks!

score 3 · Accepted Answer · edited May 23 '17 at 12:07

3

You can add the following line to your config.ru file. This will disable buffering to stdout and allows your puts commands to stdout to appear correctly in the log output.

$stdout.sync = true

See the answer at What STDOUT.sync = true means? for more details about how puts buffers.

edited May 23 '17 at 12:07

Community

1
1

answered Oct 08 '15 at 16:48

jimmc

585
2
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Thanks a lot. I was not aware of this... worked fine. – Jose Miguel Ordax Oct 08 '15 at 17:04

score -1 · Answer 2 · answered Oct 08 '15 at 14:30

-1

Not Sure but have you tried the following links

https://developer.ibm.com/answers/questions/21548/debugging-a-ruby-app-in-bluemix-with-puts-or-print-statements-written-to-the-log-is-it-possible.html

http://www.ibm.com/developerworks/aix/library/au-unix-commandline/

answered Oct 08 '15 at 14:30

Amol

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the first one is the url I already commented as tried in my question. The second one, I don't see how it helps... – Jose Miguel Ordax Oct 08 '15 at 14:34
@Amol - this should be added as comments not answers. – Alex da Silva Oct 08 '15 at 15:14

How to write to stdout with Ruby on Bluemix?

2 Answers2