Include an error message if we can't find an external document.

asl_articles/__init__.py

@@ -85,6 +85,7 @@ app.config.update( _cfg )
 # connect to the database
 # NOTE: We assume that this web server will only be handling a single user. If we ever have
 # multiple concurrent users, we will need to change to per-session database connections.
+app.config[ "_IS_CONTAINER" ] = _cfg.get( "IS_CONTAINER" )
 if _cfg.get( "IS_CONTAINER" ):
     # if we are running in a container, the database must be specified in an env variable e.g.
     #   docker run -e DBCONN=...

asl_articles/docs.py

@@ -1,5 +1,7 @@
 """ Provide access to external documents. """
 
+import os
+
 from flask import abort, send_from_directory
 
 from asl_articles import app
@@ -11,5 +13,10 @@ def get_external_doc( path ):
     """Return an external document."""
     base_dir = app.config.get( "EXTERNAL_DOCS_BASEDIR" )
     if not base_dir:
-        abort( 404 )
+        abort( 404, "EXTERNAL_DOCS_BASEDIR not configured." )
+    fname = os.path.join( base_dir, path )
+    if not os.path.isfile( fname ):
+        if app.config["_IS_CONTAINER"]:
+            fname = os.path.join( os.environ["EXTERNAL_DOCS_BASEDIR"], path )
+        abort( 404, "Can't find file: {}".format( fname ) )
     return send_from_directory( base_dir, path )

docker-compose.yml

@@ -35,3 +35,4 @@ services:
         - $EXTERNAL_DOCS_BASEDIR:/data/docs/
         environment:
         - DBCONN
+        - EXTERNAL_DOCS_BASEDIR