docs: REANA usage instructions

Readme.md

@@ -1,4 +1,6 @@
-# Reana example - FCC-hh Full Simulation Tracker Performance study
+# REANA example - FCC-hh Full Simulation Tracker Performance study
+
+## About
 
 This example reproduces one curve of figure 7.12 from the Conceptual Design Report (CDR) of the
 hadronic Future Circular Collider (FCC-hh) <http://cds.cern.ch/record/2651300> .
@@ -26,4 +28,50 @@ tracks, which can be plotted with the python script `plot_single_particle_resolu
 The pink curve corresponds to the one in figure 7.12.
 While the Riemann Fit cannot correctly estimate the resolutions for low momentum tracks, whose
 errors are dominated by scattering, the agreement of the high momentum tracks with the analytical
-methods is good. 
+methods is good.
+
+## How to run the example on REANA cloud
+
+[REANA](http://www.reana.io/) is a reproducible and reusable research data
+analysis platform that permits to run structured computational workflows on
+remote compute clouds.
+
+1. First, set up ``reana-client`` that will be used to submit the
+analysis to REANA cloud:
+
+   ```console
+   $ # on lxplus.cern.ch, you can use a provided environment:
+   $ source ~simko/public/reana/bin/activate
+
+   $ # on your laptop, you can create one as follows:
+   $ virtualenv ~/.virtualenvs/reana
+   $ source ~/.virtualenvs/reana/bin/activate
+   $ pip install reana-client  # FIXME: needs a new release on PyPI
+   ```
+
+2. Second, configure the client to connect the wanted REANA instance where the
+analysis will run, using the access token that was provided to you by the REANA
+instance administrators:
+
+   ```console
+   $ export REANA_SERVER_URL=http://reana.cern.ch/
+   $ export REANA_ACCESS_TOKEN=XXXXXXX
+   ```
+
+3. Third, you can now use ``reana-client`` to create new workflow, upload input
+   code, start the execution, check its status, logs, produced output files and
+   download the plots:
+
+   ```console
+   $ reana-client create -n fcchh-fullsim
+   $ export REANA_WORKON=fcchh-fullsim
+   $ reana-client upload
+   $ reana-client start
+   $ reana-client status
+   $ reana-client logs
+   $ reana-client list
+   $ reana-client download numHitsPerTrack.png
+   ```
+
+For more information on how to interact with the REANA platform, please see
+[reana-client documentation](https://reana-client.readthedocs.io/).

reana.yaml

@@ -17,7 +17,9 @@ workflow:
             --singlePart --particle 13 --etaMin 0 --etaMax 6 --discretePt
             --pt 1000 2000 5000 10000 100000 1000000 10000000
             --pathToDetector /usr/local/
+          | tee simulation.log 2> simulation.err
         - source /etc/profile &&
           root -b 'script/numHitsPerTrack.C("muons_for_seeding_discrete_pt.root")'
+          | tee plot-tracker-hits.log 2> plot-tracker-hits.err
         # - source /etc/profile && fccrun.py config/single_particle_trackFits.py --inputfile muons_for_seeding_discrete_pt.root --outputfile single_particle_resolutions.root
         # - source /etc/profile && python script/plot_single_particle_resolutions.py