diff --git a/Dockerfile b/Dockerfile
index 860b894..9a551be 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,8 @@
 FROM python:3.6
 VOLUME /mapping
 
+LABEL MAINTAINER "Yuri Astrakhan <YuriAstrakhan@gmail.com>"
+
 WORKDIR /usr/src/app
 
 # Copy requirements.txt first to avoid pip install on every code change
@@ -9,4 +11,10 @@ RUN pip install --no-cache-dir -r requirements.txt
 
 COPY . /usr/src/app/
 
-CMD ["python", "-u","/usr/src/app/server.py"]
+ENTRYPOINT ["python", "server.py"]
+
+# Users can easily override prepared file with their own:
+#
+#   docker run -it --rm --net=host -v "$PWD:/mapping" openmaptiles/postserve /mapping/myfile.sql
+#
+CMD ["/mapping/mvt/maketile_prep.sql"]
diff --git a/requirements.txt b/requirements.txt
index 42dcd2f..9f14259 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 tornado==6.0.1
 psycopg2-binary==2.7.7
+docopt==0.6.2