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
+# [Optional] If your requirements rarely change, uncomment this section to add them to the image.
-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.
 # 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
+# [Optional] Create alternate global install location where the vscode user can write w/o sudo
-RUN apt-get update \
+ENV PIP_TARGET=/usr/local/pip-global
-    && apt-get -y install --no-install-recommends apt-utils dialog 2>&1 \
+ENV PYTHONPATH=${PIP_TARGET}:${PYTHONPATH}
-    #
+ENV PATH=${PIP_TARGET}/bin:${PATH}
-    # Verify git, process tools, lsb-release (common in install instructions for CLIs) installed
+RUN mkdir -p ${PIP_TARGET} \
-    && apt-get -y install git iproute2 procps lsb-release \
+    && chown vscode:root ${PIP_TARGET} \
-    #
+    && export SNIPPET="if [ \"\$(stat -c '%U' ${PIP_TARGET})\" != \"vscode\" ]; then chown -R vscode:root ${PIP_TARGET}; fi" \
-    # Install pylint
+    && echo "$SNIPPET" | tee -a /root/.bashrc >> /home/vscode/.bashrc \
-    && pip --disable-pip-version-check --no-cache-dir install pylint \
+    && echo "$SNIPPET" | tee -a /root/.zshrc >> /home/vscode/.zshrc
-    #
-    # 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] 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

.devcontainer/devcontainer.json

@@ -1,30 +1,42 @@
 {
-	"name": "Python 3",
+	"name": "Python 3 Sample",
-	"context": "..",
+	"build": {
-	"dockerFile": "Dockerfile",
+		"dockerfile": "Dockerfile",
+		"context": "..",
+		// Update 'VARIANT' to pick a Python version. Rebuild the container 
+		// if it already exists to update. Available variants: 3, 3.6, 3.7, 3.8 
+		"args": { "VARIANT": "3.7" }
+	},
 
-	// Use 'settings' to set *default* container specific settings.json values on container create. 
+	// Set *default* container specific settings.json values on container create.
-	// You can edit these settings after create using File > Preferences > Settings > Remote.
 	"settings": { 
 		"terminal.integrated.shell.linux": "/bin/bash",
 		"python.pythonPath": "/usr/local/bin/python",
 		"python.linting.enabled": true,
 		"python.linting.pylintEnabled": true,
-		"python.linting.pylintPath": "/usr/local/share/pip-global/bin/pylint"
+		"python.formatting.autopep8Path": "/usr/local/py-utils/bin/autopep8",
+		"python.formatting.blackPath": "/usr/local/py-utils/bin/black",
+		"python.formatting.yapfPath": "/usr/local/py-utils/bin/yapf",
+		"python.linting.banditPath": "/usr/local/py-utils/bin/bandit",
+		"python.linting.flake8Path": "/usr/local/py-utils/bin/flake8",
+		"python.linting.mypyPath": "/usr/local/py-utils/bin/mypy",
+		"python.linting.pycodestylePath": "/usr/local/py-utils/bin/pycodestyle",
+		"python.linting.pydocstylePath": "/usr/local/py-utils/bin/pydocstyle",
+		"python.linting.pylintPath": "/usr/local/py-utils/bin/pylint",
+		"python.testing.pytestPath": "/usr/local/py-utils/bin/pytest"
 	},
 
-	// Use 'appPort' to create a container with published ports. If the port isn't working, be sure
+	// Add the IDs of extensions you want installed when the container is created.
-	// your server accepts connections from all interfaces (0.0.0.0 or '*'), not just localhost.
-	"appPort": [ 9000 ],
-
-	// Install flask and any other dependencies
-	"postCreateCommand": "pip install -r requirements.txt",
-
-	// Comment out next line to run as root
-	"remoteUser": "vscode",
-
-	// Add the IDs of extensions you want installed when the container is created in the array below.
 	"extensions": [
 		"ms-python.python"
-	]
+	],
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	"forwardPorts": [9000],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	"postCreateCommand": "pip3 install -r requirements.txt",
+
+	// Uncomment to connect as a non-root user. See https://aka.ms/vscode-remote/containers/non-root.
+	"remoteUser": "vscode"
 }

README.md

@@ -35,9 +35,9 @@ Some things to try:
    - Try adding some code and check out the language features.
 2. **Terminal:** 
     - Press <kbd>ctrl</kbd>+<kbd>shift</kbd>+<kbd>\`</kbd> to open a terminal window.
-    - Type `python -m flask run --host 0.0.0.0 --port 9000 --no-debugger --no-reload` to run the app.
+    - Type `python -m flask run --port 9000 --no-debugger --no-reload` to run the app.
-        > **Note:** It is important to add `--host 0.0.0.0` when using `appPort` in `devcontainer.json` since this uses Docker to "publish" the port rather than forwarding it. It therefore will not work if the application only listens to localhost.
     - Open a local browser and go to `http://localhost:9000` to see the running app.
+      > **Tip:** If you use this container outside of VS Code via `docker run` with `-p 9000`, you may need to append `--host 0.0.0.0` to the command above. The `-p` option "publishes" the port rather than forwarding it. It therefore will not work if the application only listens to localhost. The `forwardPorts` property in `devcontainer.json` does not have this limitation, but you can use `appPort` to publish instead if you prefer.
 3. **Build, Run, and Debug:**
    - Open `app.py`
    - Add a breakpoint (e.g. on line 9).