Merge branch 'roneil-lbexec-ganga' into 'master'

Added lbexec ganga workaround to docs

See merge request !732

doc/tutorials/running.rst

@@ -48,8 +48,8 @@ Make a file named ``my_module.py`` that contains a function that takes an ``opti
 
 Also make a file named ``options.yaml`` containing:
 
-.. code-block:: yaml
 
+.. code-block:: yaml
     input_files:
     - root://eoslhcb.cern.ch//eos/lhcb/wg/dpa/wp3/tests/hlt2_passthrough_thor_lines.dst
     annsvc_config: root://eoslhcb.cern.ch//eos/lhcb/wg/dpa/wp3/tests/hlt2_passthrough_thor_lines.tck.json
@@ -77,3 +77,44 @@ Options YAML
 ------------
 
 The full schema with which the ``options.yaml`` file is parsed can be found in :class:`~DaVinci.Options`.
+
+
+Running in Ganga
+----------------
+
+Ganga does not support ``lbexec``, yet! A workaround has been prepared, as follows:
+
+1. Add this to the end of your DaVinci options file e.g. ``my_module.py``
+
+.. code-block:: python
+
+    import sys
+    if sys.argv[0].endswith("gaudirun.py"):
+        import yaml
+        from DaVinci import Options
+        with open("options.yaml", "r") as f:
+            options = Options(**yaml.safe_loads(f))
+        print_decay_tree(options)  # make sure to rename print_decay_tree to whatever your function is called
+
+2. Add ``my_module.py`` to your ``GaudiExec`` application ``options`` list, and ``options.yaml`` to your ``job.inputfiles`` (input sandbox.)
+
+.. code-block:: python
+
+    j = Job()
+    j.backend = Dirac()  # as required
+    j.application = GaudiExec(
+        dir="DaVinci_v62r0",
+        platform="x86_64_v3-centos7-gcc11-opt+g"
+    )
+    j.application.options = ["my_module.py"]
+    j.inputdata = ...  # as required
+    j.inputfiles = ["hlt2.tck.json", "options.yaml"]  # change as required
+    j.outputfiles = [DiracFile("*.root"), LocalFile("stdout")]  # change as required
+
+    # ... configure as required ...
+
+    j.submit()
+
+
+
+3. Submit your jobs as usual. Note that in ``options.yaml``, ``input_files`` should be set to a dummy value, as it is overwritten later.