dockerfile-update-3

Dockerfile

@@ -1,23 +1,75 @@
-FROM python:alpine
+# syntax=docker/dockerfile:1
+# Keep this syntax directive! It's used to enable Docker BuildKit
+
+# Based on https://github.com/python-poetry/poetry/discussions/1879?sort=top#discussioncomment-216865
+
+FROM python:alpine as python-base
+
+    # python
+ENV PYTHONUNBUFFERED=1 \
+    # prevents python creating .pyc files
+    PYTHONDONTWRITEBYTECODE=1 \
+    \
+    # pip
+    PIP_DISABLE_PIP_VERSION_CHECK=on \
+    PIP_DEFAULT_TIMEOUT=100 \
+    \
+    # poetry
+    # https://python-poetry.org/docs/configuration/#using-environment-variables
+    POETRY_VERSION=1.8.0 \
+    # make poetry install to this location
+    POETRY_HOME="/opt/poetry" \
+    # make poetry create the virtual environment in the project's root
+    # it gets named `.venv`
+    POETRY_VIRTUALENVS_IN_PROJECT=true \
+    # do not ask any interactive question
+    POETRY_NO_INTERACTION=1 \
+    \
+    # paths
+    # this is where our requirements + virtual environment will live
+    PYSETUP_PATH="/opt/pysetup" \
+    VENV_PATH="/opt/pysetup/.venv"
+
+
+# prepend poetry and venv to path
+ENV PATH="$POETRY_HOME/bin:$VENV_PATH/bin:$PATH"
+
+
+################################
+# BUILDER-BASE
+# Used to build deps + create our virtual environment
+################################
+FROM python-base as builder
 
 # Update package lists and install necessary dependencies
 RUN apk update && \
-    apk add --no-cache build-base icu-data-full curl python3-dev musl-dev postgresql-dev postgresql-client && \
-    curl -sSL https://install.python-poetry.org | python
+    apk add --no-cache build-base icu-data-full curl python3-dev musl-dev postgresql-dev postgresql-client
+
+# install poetry - respects $POETRY_VERSION & $POETRY_HOME
+# The --mount will mount the buildx cache directory to where
+# Poetry and Pip store their cache so that they can re-use it
+RUN --mount=type=cache,target=/root/.cache \
+    curl -sSL https://install.python-poetry.org | python3 -
+
+# copy project requirement files here to ensure they will be cached.
+WORKDIR $PYSETUP_PATH
+COPY poetry.lock pyproject.toml ./
+
+# install runtime deps - uses $POETRY_VIRTUALENVS_IN_PROJECT internally
+RUN --mount=type=cache,target=/root/.cache \
+    poetry install --without=dev
+
+
+################################
+# Final image used for runtime
+################################
+FROM python-base
+
+COPY --from=builder $PYSETUP_PATH $PYSETUP_PATH
+COPY ./app /app/
 
-# Set working directory
 WORKDIR /app
 
-# Install dependencies
-RUN poetry config virtualenvs.create false && \
-    poetry install --no-dev
-
-# Copy just the dependency manifests first
-COPY poetry.lock pyproject.toml /app/
-
-# Copy the rest of the application
-COPY . /app
-
 # Expose the port
 EXPOSE 8000