Add support for remote logging in feelpp

[prudhomm]

The application logger is already integrated and deployed in http://portal-dev.mso4sc.eu. The experiments tool at portal-dev now displays 2 buttons, 'Execution logs' and 'Application logs'. If you click in application logs now you can see your experiments logs in real time.

To integrate your application with the logger you have to introduce minor modification to your current blueprints.

• Add a log filter YAML file
• Launch the remotelogger to track your application logs

We have created a blueprint example to show how it works. You can find it in the following link:

https://github.com/MSO4SC/resources/tree/master/blueprint-examples/single-singularity-logger

Note that a new job_option 'pre' has been added. This is a list of shell commands that run before the 'command' job_option in the sbatch script.

To launch the logger within your simulation, you have to add exactly the following to your blueprint:

---

pre:
- 'singularity run -B /mnt remotelogger-cli.simg -f logfilter.yaml -sh logging.mso4sc.eu -u mso4sc -p remotelogger -rk $CFY_EXECUTION_ID -q $CFY_JOB_NAME &'

The same line is in the provided blueprint example:
https://github.com/MSO4SC/resources/blob/master/blueprint-examples/single-singularity-logger/blueprint.yaml#L71

You have to be aware that the 'logfilter.yaml' is the glue between your application and the logger. This is a YAML file in which you must specify the path to the file you want to track (the application log file).

In the example we create the 'logfilter.yaml' file during the bootstrap process. You can see how we are doing this in the following link:
https://github.com/MSO4SC/resources/blob/master/blueprint-examples/single-singularity-logger/scripts/bootstrap.sh#L8

Additionally you can filter your log lines using regular expressions. You can get more info about how to use the application logger command line interface in the following link:

https://github.com/MSO4SC/remotelogger-cli