Tightened up the Dockerfile.

Dockerfile

@@ -1,65 +1,57 @@
 # NOTE: Use the run-container.sh script to build and launch this container.
 
-# We do a multi-stage build (requires Docker >= 17.05) to install everything, then copy it all
-# to the final target image.
+FROM centos:8
 
-FROM centos:8 AS base
+# update packages
+RUN dnf -y upgrade-minimal
 
-# update packages and install Python and Java
-RUN dnf -y upgrade-minimal && \
-    dnf install -y python36 && \
-    curl -s "https://download.java.net/java/GA/jdk15.0.1/51f4f36ad4ef43e39d0dfdbaf6549e32/9/GPL/openjdk-15.0.1_linux-x64_bin.tar.gz" | tar -C /usr/bin/ -xz && \
-    dnf clean all
+# install Python
+RUN dnf install -y python36
 
-# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
-FROM base AS build
-
-# set up a virtualenv
-RUN python3.6 -m venv /opt/venv
-ENV PATH="/opt/venv/bin:$PATH"
-RUN pip install --upgrade pip
-
-# install the application requirements
-COPY requirements.txt requirements-dev.txt ./
-RUN pip install -r requirements.txt
-ARG ENABLE_TESTS
-RUN if [ "$ENABLE_TESTS" ]; then pip install -r requirements-dev.txt ; fi
-
-# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
-FROM base
-
-# copy the virtualenv from the build image
-COPY --from=build /opt/venv /opt/venv
-ENV PATH="/opt/venv/bin:$PATH"
+# install Java
+RUN curl -s "https://download.java.net/java/GA/jdk15.0.1/51f4f36ad4ef43e39d0dfdbaf6549e32/9/GPL/openjdk-15.0.1_linux-x64_bin.tar.gz" \
+    | tar -C /usr/bin/ -xz
 
 # install Firefox
-RUN dnf install -y wget bzip2 xorg-x11-server-Xvfb gtk3 dbus-glib
-RUN wget -qO- "https://download.mozilla.org/?product=firefox-latest-ssl&os=linux64&lang=en-US" | tar -C /usr/local/ -jx && \
+RUN dnf install -y wget bzip2 xorg-x11-server-Xvfb gtk3 dbus-glib && \
+    wget -qO- "https://download.mozilla.org/?product=firefox-latest-ssl&os=linux64&lang=en-US" \
+        | tar -C /usr/local/ -jx && \
     ln -s /usr/local/firefox/firefox /usr/bin/firefox && \
-    echo "exclude=firefox" >> /etc/dnf/dnf.conf
+    echo "exclude=firefox" >>/etc/dnf/dnf.conf
 
 # install geckodriver
 RUN url=$( curl -s https://api.github.com/repos/mozilla/geckodriver/releases/latest | grep -Poh 'https.*linux64\.tar\.gz(?!\.)' ) && \
-    curl -sL "$url" | tar -C /usr/bin/ -xz
+    curl -sL "$url" \
+        | tar -C /usr/bin/ -xz
 
-# install the application
-WORKDIR /app
-COPY vasl_templates vasl_templates
-COPY vassal-shim/release/vassal-shim.jar vassal-shim/release/
-COPY setup.py requirements.txt requirements-dev.txt LICENSE.txt ./
-RUN pip install -e .
+# clean up
+RUN dnf clean all
 
-# copy the config files
-COPY docker/config/* vasl_templates/webapp/config/
+# install the application requirements
+WORKDIR /app
+COPY requirements.txt requirements-dev.txt ./
+RUN pip3 install -r requirements.txt
 ARG ENABLE_TESTS
-RUN if [ "$ENABLE_TESTS" ]; then echo "ENABLE_REMOTE_TEST_CONTROL = 1" >>vasl_templates/webapp/config/debug.cfg ; fi
+RUN if [ "$ENABLE_TESTS" ]; then \
+    pip3 install -r requirements-dev.txt \
+; fi
+
+# install the application
+COPY vasl_templates/webapp/ ./vasl_templates/webapp/
+COPY vassal-shim/release/vassal-shim.jar ./vassal-shim/release/
+COPY setup.py LICENSE.txt ./
+RUN pip3 install --editable .
+
+# install the config files
+COPY docker/config/ ./vasl_templates/webapp/config/
+RUN if [ "$ENABLE_TESTS" ]; then \
+    echo "ENABLE_REMOTE_TEST_CONTROL = 1" >>vasl_templates/webapp/config/debug.cfg \
+; fi
 
 # create a new user
 RUN useradd --create-home app
 USER app
 
 EXPOSE 5010
-COPY docker/run.sh .
+COPY docker/run.sh ./
 CMD ./run.sh

docker/run.sh

@@ -6,4 +6,4 @@ export DISPLAY=:10.0
 Xvfb :10 -ac 1>/tmp/xvfb.log 2>/tmp/xvfb.err &
 
 # run the webapp server
-python /app/vasl_templates/webapp/run_server.py
+python3 /app/vasl_templates/webapp/run_server.py