Add Dockerfile and instructions on use

Dockerfile

@@ -0,0 +1,46 @@
+# syntax=docker/dockerfile:1
+
+# Comments are provided throughout this file to help you get started.
+# If you need more help, visit the Dockerfile reference guide at
+# https://docs.docker.com/reference/dockerfile/
+
+################################################################################
+# Create a stage for building the application.
+
+ARG RUST_VERSION=1.70.0
+ARG APP_NAME=taskchampion-sync-server
+FROM rust:${RUST_VERSION}-slim-bullseye AS build
+ARG APP_NAME
+WORKDIR /app
+
+# Build the application.
+# Leverage a cache mount to /usr/local/cargo/registry/
+# for downloaded dependencies and a cache mount to /app/target/ for 
+# compiled dependencies which will speed up subsequent builds.
+# Leverage a bind mount to the src directory to avoid having to copy the
+# source code into the container. Once built, copy the executable to an
+# output directory before the cache mounted /app/target is unmounted.
+RUN --mount=type=bind,source=src,target=src \
+    --mount=type=bind,source=Cargo.toml,target=Cargo.toml \
+    --mount=type=bind,source=Cargo.lock,target=Cargo.lock \
+    --mount=type=cache,target=/app/target/ \
+    --mount=type=cache,target=/usr/local/cargo/registry/ \
+    <<EOF
+set -e
+cargo build --locked --release
+cp ./target/release/$APP_NAME /bin/server
+EOF
+
+################################################################################
+# Create a new stage for running the application that contains the minimal
+# runtime dependencies for the application.
+FROM debian:bullseye-slim AS final
+
+# Copy the executable from the "build" stage.
+COPY --from=build /bin/server /bin/
+
+# Expose the port that the application listens on.
+EXPOSE 8080
+
+# What the container should run when it is started.
+CMD ["/bin/server"]

README.md

@@ -8,3 +8,20 @@ This repository implements a sync server against which Taskwarrior and other app
 
 This repository was spun off from Taskwarrior itself after the 3.0.0 release.
 It is still under development and currently best described as a refernce implementation of the Taskchampion sync protocol.
+
+## Installation and usage
+
+### Using docker
+
+1. Set `$TASKCHAMPION_DATA_DIR` to a place where you want to keep sync server data.
+2. Build and run the image:
+
+```bash
+docker build . -t taskchampion-sync-server
+docker run --rm \
+    -p 8080:8080 \
+    --name taskchampion-sync-server \
+    -e RUST_LOG=debug \
+    --mount type=bind,source=$TASKCHAMPION_DATA_DIR,target=/var/lib/taskchampion-sync-server \ 
+    taskchampion-sync-server
+```