Add node name to the output in rosout.log

[patrickcjh]

Fixes #912.

[dirk-thomas]

@ros-pull-request-builder retest this please

[IanTheEngineer]

@commaster90 can you give us a sample of what the text output was before, and a sample of what your change will produce?

[dirk-thomas]

Just to make this change more visible. In this line the missing ] has been added. Without the change the brackets are unbalanced.

[patrickcjh]

This is an example output in ~/.ros/latest/rosout.log before the change.

1477675270.252137195 INFO [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main) [topics: /rosout, /chatter] hello world 2
1477675270.351831526 INFO [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main) [topics: /rosout, /chatter] hello world 3
1477675270.451983685 INFO [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main) [topics: /rosout, /chatter] hello world 4
1477675270.551896309 INFO [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main) [topics: /rosout, /chatter] hello world 5
1477675270.651884679 INFO [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main) [topics: /rosout, /chatter] hello world 6

And this will be the output in ~/.ros/latest/rosout.log after the change.

1477674754.711808141 INFO /talker [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main)] [topics: /rosout, /chatter] hello world 2
1477674754.811829213 INFO /talker [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main)] [topics: /rosout, /chatter] hello world 3
1477674754.911385469 INFO /talker [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main)] [topics: /rosout, /chatter] hello world 4
1477674755.011573405 INFO /talker [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main)] [topics: /rosout, /chatter] hello world 5
1477674755.110618167 INFO /talker [/tmp/binarydeb/ros-indigo-roscpp-tutorials-0.5.5/talker/talker.cpp:111(main)] [topics: /rosout, /chatter] hello world 6

[IanTheEngineer]

That makes sense, but I think I'm a bit confused. I thought the output format was dictated by the rosconsole config file:
http://wiki.ros.org/rosconsole#Console_Output_Formatting
It appears that it was never used in rosout.log at all. Your change seems like a sensible default, but could break any code that attempts to parse this file. I've written a script like this in the past, but I'm not particularly bothered, as it would be easy to fix. However, if we obeyed the console output formatting in the rosout log, then users could easily configure to add / remove console output formatting fields as they desire.

[patrickcjh]

@IanTheEngineer It is my concern too that this might break other code that parse rosout.log. Therefore, I would like to seek opinion here.

I notice that the rosconsole config file you mentioned affects only the output shown on the console, and the config can be different for every node. It however does not log any output to file. It is also a bit confusing because for Python nodes, individual log files for each nodes are generated in the ~/.ros/latest folder (whereas C++ nodes do not have individual logs). Meanwhile, rosout is running within roscore, and it aggregates the log from every nodes and write it to a single rosout.log

[IanTheEngineer]

Ah, that is nearly true. The rosconsole var only affects the stdout if you are running with rosrun, or with a roslaunch node set to output=console. But if you are setting roslaunch output=log, then this rosconsole config environment var dictates the output fields of each line in the *-stdout.log.
Anyway, that's getting into the weeds a bit. I have observed that the rosout.log ignores this configuration regardless, as is now obvious by looking at this file that you updated. I am not opposed to your change, but think we should open a ticket to address this inconsistency between log formatting.

[dirk-thomas]

I have cherry-picked your patch to the newly created lunar-devel branch: bc9222a

Thank you!