Update to use Python pre-built image

.devcontainer/Dockerfile

@@ -3,60 +3,36 @@
 # Licensed under the MIT License. See https://go.microsoft.com/fwlink/?linkid=2090316 for license information.
 #-------------------------------------------------------------------------------------------------------------
 
-FROM python:3
+# Update the VARIANT arg in devcontainer.json to pick a Python version: 3, 3.8, 3.7, 3.6 
+# To fully customize the contents of this image, use the following Dockerfile instead:
+# https://github.com/microsoft/vscode-dev-containers/tree/v0.109.0/containers/python-3/.devcontainer/base.Dockerfile
+ARG VARIANT=3
+FROM mcr.microsoft.com/vscode/devcontainers/python:0-${VARIANT}
 
-# Avoid warnings by switching to noninteractive
-ENV DEBIAN_FRONTEND=noninteractive
-
-# This Dockerfile adds a non-root user with sudo access. Use the "remoteUser"
-# property in devcontainer.json to use it. On Linux, the container user's GID/UIDs
-# will be updated to match your local UID/GID (when using the dockerFile property).
-# See https://aka.ms/vscode-remote/containers/non-root-user for details.
-ARG USERNAME=vscode
-ARG USER_UID=1000
-ARG USER_GID=$USER_UID
-
-ENV PIP_TARGET=/usr/local/share/pip-global
-ENV PYTHONPATH=${PYTHONPATH}:${PIP_TARGET}
-ENV PATH=${PATH}:${PIP_TARGET}/bin
-
-# Uncomment the following COPY line and the corresponding lines in the `RUN` command if you wish to
-# include your requirements in the image itself. It is suggested that you only do this if your
-# requirements rarely (if ever) change.
+# [Optional] If your requirements rarely change, uncomment this section to add them to the image.
+#
 # COPY requirements.txt /tmp/pip-tmp/
+# RUN pip3 --disable-pip-version-check --no-cache-dir install -r /tmp/pip-tmp/requirements.txt \
+#    && rm -rf /tmp/pip-tmp
 
-# Configure apt and install packages
-RUN apt-get update \
-    && apt-get -y install --no-install-recommends apt-utils dialog 2>&1 \
-    #
-    # Verify git, process tools, lsb-release (common in install instructions for CLIs) installed
-    && apt-get -y install git iproute2 procps lsb-release \
-    #
-    # Install pylint
-    && pip --disable-pip-version-check --no-cache-dir install pylint \
-    #
-    # Update Python environment based on requirements.txt
-    # && pip --disable-pip-version-check --no-cache-dir install -r /tmp/pip-tmp/requirements.txt \
-    # && rm -rf /tmp/pip-tmp \
-    #
-    # Create a non-root user to use if preferred - see https://aka.ms/vscode-remote/containers/non-root-user.
-    && groupadd --gid $USER_GID $USERNAME \
-    && useradd -s /bin/bash --uid $USER_UID --gid $USER_GID -m $USERNAME \
-    # [Optional] Add sudo support for the non-root user
-    && apt-get install -y sudo \
-    && echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME\
-    && chmod 0440 /etc/sudoers.d/$USERNAME \
-    #
-    # Create alternate global install location that both uses have rights to access
-    && mkdir -p /usr/local/share/pip-global \
-    && chown ${USERNAME}:root /usr/local/share/pip-global \
-    #
-    # Clean up
-    && apt-get autoremove -y \
-    && apt-get clean -y \
-    && rm -rf /var/lib/apt/lists/*
-
-# Switch back to dialog for any ad-hoc use of apt-get
-ENV DEBIAN_FRONTEND=dialog
-
+# [Optional] Create alternate global install location where the vscode user can write w/o sudo
+ENV PIP_TARGET=/usr/local/pip-global
+ENV PYTHONPATH=${PIP_TARGET}:${PYTHONPATH}
+ENV PATH=${PIP_TARGET}/bin:${PATH}
+RUN mkdir -p ${PIP_TARGET} \
+    && chown vscode:root ${PIP_TARGET} \
+    && export SNIPPET="if [ \"\$(stat -c '%U' ${PIP_TARGET})\" != \"vscode\" ]; then chown -R vscode:root ${PIP_TARGET}; fi" \
+    && echo "$SNIPPET" | tee -a /root/.bashrc >> /home/vscode/.bashrc \
+    && echo "$SNIPPET" | tee -a /root/.zshrc >> /home/vscode/.zshrc
 
+# [Optional] Uncomment this section to install additional packages.
+#
+# ENV DEBIAN_FRONTEND=noninteractive
+# RUN apt-get update \
+#    && apt-get -y install --no-install-recommends <your-package-list-here> \
+#    #
+#    # Clean up
+#    && apt-get autoremove -y \
+#    && apt-get clean -y \
+#    && rm -rf /var/lib/apt/lists/*
+# ENV DEBIAN_FRONTEND=dialog