From a491521ef720f5d88d1440ee877745b1e39b72e6 Mon Sep 17 00:00:00 2001
From: Thomas Eizinger <thomas@eizinger.io>
Date: Thu, 15 Jun 2023 19:59:53 +0200
Subject: [PATCH] feat(relay): add Dockerfile (#1661)

This adds a basic Dockerfile for the relay so users and devs can easily
start it.
---
 rust/.dockerignore    |  1 +
 rust/relay.Dockerfile | 23 +++++++++++++++++++++++
 rust/relay/README.md  |  5 +++++
 3 files changed, 29 insertions(+)
 create mode 100644 rust/.dockerignore
 create mode 100644 rust/relay.Dockerfile

diff --git a/rust/.dockerignore b/rust/.dockerignore
new file mode 100644
index 000000000..2f7896d1d
--- /dev/null
+++ b/rust/.dockerignore
@@ -0,0 +1 @@
+target/
diff --git a/rust/relay.Dockerfile b/rust/relay.Dockerfile
new file mode 100644
index 000000000..fddb43a31
--- /dev/null
+++ b/rust/relay.Dockerfile
@@ -0,0 +1,23 @@
+# syntax=docker/dockerfile:1.5-labs
+FROM rust:1.70-slim as builder
+
+WORKDIR /workspace
+ADD . .
+RUN --mount=type=cache,target=./target \
+    --mount=type=cache,target=/usr/local/cargo/registry \
+    --mount=type=cache,target=/usr/local/rustup \
+    rustup target add x86_64-unknown-linux-musl && \
+    cargo build --release --bin relay --target x86_64-unknown-linux-musl
+
+RUN --mount=type=cache,target=./target \
+    mv ./target/x86_64-unknown-linux-musl/release/relay /usr/local/bin/relay
+
+FROM scratch
+COPY --from=builder /usr/local/bin/relay /usr/local/bin/relay
+ENV RUST_BACKTRACE=1
+
+EXPOSE 3478/udp
+EXPOSE 49152-65535/udp
+
+# This purposely does not include an `init` process. Use `docker run --init` for proper signal handling.
+ENTRYPOINT ["relay"]
diff --git a/rust/relay/README.md b/rust/relay/README.md
index 8caf6d83d..6120b5235 100644
--- a/rust/relay/README.md
+++ b/rust/relay/README.md
@@ -22,6 +22,11 @@ You can build the server using: `cargo build --release --bin relay`
 
 For a detailed help text and available configuration options, run `cargo run --bin relay -- --help`.
 
+## Docker
+
+There is a docker image one directory up from this README: [Dockerfile](../relay.Dockerfile).
+The Rust binary itself does not include any signal handling, thus you need to run the container with `--init` if you want to be able to CTRL+C the running container.
+
 ## Design
 
 The relay is designed in a sans-IO fashion, meaning the core components do not cause side effects but operate as pure, synchronous state machines.