Galaxy schema rendering script.

Uses sqlite_schemadisp to generate images like the one at
https://galaxyproject.org/admin/internals/data-model/

scripts/galaxy_schemadisp.py

@@ -0,0 +1,44 @@
+import os
+import sys
+from db_shell import *  # noqa
+
+gxy_root = os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir))
+sys.path.insert(1, os.path.abspath(os.path.join(gxy_root, 'lib')))
+
+from galaxy import model
+from sqlalchemy import MetaData
+from sqlalchemy.orm import class_mapper
+from sqlalchemy_schemadisplay import create_schema_graph, create_uml_graph
+
+if __name__ == "__main__":
+    gxy_root = os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir))
+    sqlitedb = os.path.join(gxy_root, 'database/universe.sqlite')
+    # Try to build a representation of what's in the sqlite database
+    if os.path.exists(sqlitedb):
+        graph = create_schema_graph(metadata=MetaData('sqlite:///' + sqlitedb),
+                                    show_datatypes=False,
+                                    show_indexes=False,
+                                    rankdir='LR',
+                                    concentrate=False)
+        print(f"Writing galaxy_universe.png, built from {sqlitedb}")
+        graph.write_png('galaxy_universe.png')
+    else:
+        print(f"No sqlitedb available at {sqlitedb}, skipping rendering")
+
+    # Build UML graph from loaded mapper
+    mappers = []
+    for attr in dir(model):
+        if attr[0] == '_':
+            continue
+        try:
+            cls = getattr(model, attr)
+            mappers.append(class_mapper(cls))
+        except Exception:
+            pass
+
+    graph = create_uml_graph(
+        mappers,
+        show_operations=False,
+    )
+    print("Writing galaxy_uml.png")
+    graph.write_png('galaxy_uml.png')  # write out the file