Introduce an env variable for GiBUU input dir

Dockerfile

@@ -31,4 +31,5 @@ RUN cd /km3buu/externals/km3net-dataformat/ && \
     make
 ENV KM3NET_LIB=/km3buu/externals/km3net-dataformat/lib    
 ENV CONTAINER_GIBUU_EXEC=/opt/GiBUU/release2021/objects/GiBUU.x 
+ENV CONTAINER_GIBUU_INPUT=/opt/GiBUU/buuinput 
 ENV LD_LIBRARY_PATH="/usr/local/lib:${LD_LIBRARY_PATH}"

km3buu/jobcard.py

@@ -14,13 +14,16 @@ __status__ = "Development"
 
 import f90nml
 from os.path import basename, dirname, abspath, join, isfile
+from os import environ
 
 try:
     from StringIO import StringIO
 except ImportError:
     from io import StringIO
 
-INPUT_PATH = "/opt/buuinput2021/"
+INPUT_PATH = environ.get("CONTAINER_GIBUU_INPUT")
+if INPUT_PATH is None:
+    INPUT_PATH = "/opt/buuinput2021/"
 
 DEFAULT_JOBCARD_FILENAME = "jobcard.job"