Update Dockerfile and docker-compose.yml

* Use newer Python 3.7.5 image and remove installation commands that it
  obviates
* Update maintainer to use LABEL (modern recommendation)
* Change name of app directory to be more orthodox
* Change user name to more meaningful "lmodproxy"

Dockerfile

@@ -1,29 +1,9 @@
-FROM ubuntu:xenial
-MAINTAINER ODL DevOps <mitx-devops@mit.edu>
-
-# Install base packages
-RUN apt-get update && apt-get install -y python-pip python-dev
-RUN pip install pip --upgrade
-
-# Add non-root user.
-RUN adduser --disabled-password --gecos "" mitodl
-
-# Add project
-COPY . /src
-WORKDIR /src
-RUN chown -R mitodl:mitodl /src
-RUN touch .htpasswd && chmod 666 .htpasswd && touch .cert.pem && chmod 666 .cert.pem
-
-# Install project packages
+FROM python:3.7.5-buster
+LABEL maintainer="ODL DevOps <mitx-devops@mit.edu>"
+RUN adduser --disabled-password --gecos "lmod_proxy privsep user" lmodproxy
+COPY . /opt/lmod_proxy
+WORKDIR /opt/lmod_proxy
 RUN pip install -r ./requirements.txt
-
-
-# Clean up
-RUN apt-get clean && apt-get purge
-USER mitodl
-
-# Set pip cache folder, as it is breaking pip when it is on a shared volume
-ENV XDG_CACHE_HOME /tmp/.cache
-
 EXPOSE 8080
+USER lmodproxy
 CMD uwsgi uwsgi.ini

docker-compose.yml

@@ -9,5 +9,4 @@ lmodproxy:
   ports:
     - "8080:8080"
   volumes:
-    - .:/src
-    - /tmp
+    - .:/opt/lmod_proxy