mini-docker-rust 
Very small rust docker image.
This is an example project on how to build very small docker images for a rust project. The resulting image for a working hello world was about 5.87MB during my tests.
See for yourself
You don't need to install anything besides docker. Build with docker build -t mini-docker-rust . and run with docker run mini-docker-rust.
Annotated docker file
# Start with alpine as base image
FROM alpine:latest
# Copy our project into the image (see .dockerignore for exclusions)
COPY ./ /app
# Switch the current directory to /app
WORKDIR /app
# This does multiple things in one go to keep the image size and layer number extremly low:
# llvm-libunwind is required to run the final rust binary, so we install it first
RUN apk add --no-cache llvm-libunwind \
# Next, we install rust and cargo and tag them in a virtual package called `.build-rust`
&& apk add --no-cache --virtual .build-rust rust cargo \
# Finally, we build our project
&& cargo build --release \
# After that we copy our binary to the project root (you need to adjust this to your project)
&& cp target/release/mini-docker-rust . \
# Discard the target/ and ~/.cargo/ directory so it won't bloat our image
&& rm -rf target/ ~/.cargo/ \
# As the final cleanup step we uninstall our virtual package
# This uninstalls cargo, rust and all dependencies that aren't needed anymore so they won't end up in the final image
&& apk del --purge .build-rust
# Finally, we configure our binary as entrypoint (you need to adjust this too)
ENTRYPOINT ["./mini-docker-rust"]