Update Dockerfile for Python 3.8

.travis.yml

@@ -18,6 +18,7 @@ before_install:
     - docker-compose -f .travis/docker-compose-travis.yml up -d
     - docker exec analytics_api bash -c "
       source /edx/app/analytics_api/venvs/analytics_api/bin/activate &&
+      pip install setuptools==49.6.0 &&
       make -C /edx/app/analytics_api/analytics_api travis"
     # HACK: https://github.com/nodejs/docker-node/issues/1199
     - rm package-lock.json

Dockerfile

@@ -1,8 +1,13 @@
 FROM ubuntu:xenial as openedx
 
 RUN apt update && \
-  apt install -y git-core language-pack-en python3.5 python3-pip python3-dev libmysqlclient-dev && \
-  pip3 install --upgrade pip setuptools && \
+  apt-get install -y software-properties-common && \
+  apt-add-repository -y ppa:deadsnakes/ppa && apt-get update && \
+  apt-get install -y curl && \
+  apt-get upgrade -qy && \
+  apt install -y git-core language-pack-en build-essential python3.8-dev python3.8-distutils libmysqlclient-dev && \
+  curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py && \
+  python3.8 get-pip.py && python3.8 -m pip install --upgrade pip setuptools && \
   rm -rf /var/lib/apt/lists/*
 
 RUN locale-gen en_US.UTF-8
@@ -13,7 +18,7 @@ ENV ANALYTICS_DASHBOARD_CFG /edx/etc/insights.yml
 
 WORKDIR /edx/app/analytics_dashboard
 COPY requirements /edx/app/analytics_dashboard/requirements
-RUN pip3 install -r requirements/production.txt
+RUN python3.8 -m pip install -r requirements/production.txt
 
 EXPOSE 8110
 CMD gunicorn -b 127.0.0.1:8110 --workers 2 --timeout=300 analytics_dashboard.wsgi:application
@@ -23,6 +28,6 @@ USER app
 COPY . /edx/app/analytics_dashboard
 
 FROM openedx as edx.org
-RUN pip3 install newrelic
+RUN python3.8 -m pip install newrelic
 CMD newrelic-admin run-program gunicorn -b 127.0.0.1:8110 --workers 2 --timeout=300 analytics_dashboard.wsgi:application