Add --editable flag to complement.sh which uses an editable install of Synapse for faster turn-around times whilst developing iteratively. (#14548)

Co-authored-by: Mathieu Velten <mathieuv@matrix.org>

docker/Dockerfile-workers

@@ -1,6 +1,7 @@
 # syntax=docker/dockerfile:1
 
 ARG SYNAPSE_VERSION=latest
+ARG FROM=matrixdotorg/synapse:$SYNAPSE_VERSION
 
 # first of all, we create a base image with an nginx which we can copy into the
 # target image. For repeated rebuilds, this is much faster than apt installing
@@ -23,7 +24,7 @@ FROM debian:bullseye-slim AS deps_base
 FROM redis:6-bullseye AS redis_base
 
 # now build the final image, based on the the regular Synapse docker image
-FROM matrixdotorg/synapse:$SYNAPSE_VERSION
+FROM $FROM
 
     # Install supervisord with pip instead of apt, to avoid installing a second
     # copy of python.

docker/complement/Dockerfile

@@ -7,8 +7,9 @@
 # https://github.com/matrix-org/synapse/blob/develop/docker/README-testing.md#testing-with-postgresql-and-single-or-multi-process-synapse
 
 ARG SYNAPSE_VERSION=latest
+ARG FROM=matrixdotorg/synapse-workers:$SYNAPSE_VERSION
 
-FROM matrixdotorg/synapse-workers:$SYNAPSE_VERSION
+FROM $FROM
     # First of all, we copy postgres server from the official postgres image,
     # since for repeated rebuilds, this is much faster than apt installing
     # postgres each time.

docker/editable.Dockerfile

@@ -0,0 +1,75 @@
+# syntax=docker/dockerfile:1
+# This dockerfile builds an editable install of Synapse.
+#
+# Used by `complement.sh`. Not suitable for production use.
+
+ARG PYTHON_VERSION=3.9
+
+###
+### Stage 0: generate requirements.txt
+###
+# We hardcode the use of Debian bullseye here because this could change upstream
+# and other Dockerfiles used for testing are expecting bullseye.
+FROM docker.io/python:${PYTHON_VERSION}-slim-bullseye
+
+# Install Rust and other dependencies (stolen from normal Dockerfile)
+# install the OS build deps
+RUN \
+   --mount=type=cache,target=/var/cache/apt,sharing=locked \
+   --mount=type=cache,target=/var/lib/apt,sharing=locked \
+ apt-get update -qq && apt-get install -yqq \
+    build-essential \
+    libffi-dev \
+    libjpeg-dev \
+    libpq-dev \
+    libssl-dev \
+    libwebp-dev \
+    libxml++2.6-dev \
+    libxslt1-dev \
+    openssl \
+    zlib1g-dev \
+    git \
+    curl \
+    gosu \
+    libjpeg62-turbo \
+    libpq5 \
+    libwebp6 \
+    xmlsec1 \
+    libjemalloc2 \
+    && rm -rf /var/lib/apt/lists/*
+ENV RUSTUP_HOME=/rust
+ENV CARGO_HOME=/cargo
+ENV PATH=/cargo/bin:/rust/bin:$PATH
+RUN mkdir /rust /cargo
+RUN curl -sSf https://sh.rustup.rs | sh -s -- -y --no-modify-path --default-toolchain stable --profile minimal
+
+
+# Make a base copy of the editable source tree, so that we have something to
+# install and build now — even though it's going to be covered up by a mount
+# at runtime.
+COPY synapse /editable-src/synapse/
+COPY rust /editable-src/rust/
+# ... and what we need to `pip install`.
+COPY pyproject.toml poetry.lock README.rst build_rust.py Cargo.toml Cargo.lock /editable-src/
+
+RUN pip install poetry
+RUN poetry config virtualenvs.create false
+RUN cd /editable-src && poetry install --extras all
+
+# Make copies of useful things for inspection:
+# - the Rust module (must be copied to the editable source tree before startup)
+# - poetry.lock is useful for checking if dependencies have changed.
+RUN cp /editable-src/synapse/synapse_rust.abi3.so /synapse_rust.abi3.so.bak
+RUN cp /editable-src/poetry.lock /poetry.lock.bak
+
+
+### Extra setup from original Dockerfile
+COPY ./docker/start.py /start.py
+COPY ./docker/conf /conf
+
+EXPOSE 8008/tcp 8009/tcp 8448/tcp
+
+ENTRYPOINT ["/start.py"]
+
+HEALTHCHECK --start-period=5s --interval=15s --timeout=5s \
+    CMD curl -fSs http://localhost:8008/health || exit 1