Initial commit

Author: kpcyrd

.dockerignore

@@ -0,0 +1,5 @@
+target
+Dockerfile
+.dockerignore
+.git
+.gitignore

.gitignore

@@ -0,0 +1,4 @@
+target/
+**/*.rs.bk
+*.swp
+*.swo

Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "mini-docker-rust"
+version = "0.1.0"
+authors = ["user"]
+
+[dependencies]

Dockerfile

@@ -0,0 +1,11 @@
+FROM alpine:edge
+COPY ./ /app
+WORKDIR /app
+RUN echo http://nl.alpinelinux.org/alpine/edge/testing >> /etc/apk/repositories \
+	&& apk add --no-cache llvm-libunwind \
+	&& apk add --no-cache --virtual .build-rust rust cargo \
+	&& cargo build --release \
+	&& cp target/release/foo . \
+	&& rm -rf target/ \
+	&& apk del --purge .build-rust
+ENTRYPOINT ["./foo"]

README.md

@@ -0,0 +1,38 @@
+# 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 6.55MB 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 build -t mini-docker-rust`.
+
+## Annotated docker file
+
+```
+# Start with alpine edge as a base image. (edge is required at the point of writing)
+FROM alpine:edge
+# 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:
+# First we enable the testing repo (required at the point of writing)
+RUN echo http://nl.alpinelinux.org/alpine/edge/testing >> /etc/apk/repositories \
+    # llvm-libunwind is required to run the final rust binary, so we install it first
+	&& 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/foo . \
+    # And discard the target/ directory so it won't bloat our image
+	&& rm -rf target/ \
+    # 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 ["./foo"]
+```

src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}