use multistage to build boringtun

Dockerfile

@@ -9,6 +9,12 @@
 # #
 # #
 
+# Build boringtun
+FROM rust:1.62.1 AS boringtun-builder
+RUN rustup target add x86_64-unknown-linux-musl
+RUN apt-get update && apt-get install -y musl-tools && \
+  cargo install boringtun-cli --target x86_64-unknown-linux-musl
+
 FROM docker.io/library/node:14-alpine@sha256:dc92f36e7cd917816fa2df041d4e9081453366381a00f40398d99e9392e78664 AS build_node_modules
 
 # Copy Web UI
@@ -38,7 +44,8 @@ RUN apk add -U --no-cache \
   wireguard-tools \
   dumb-init
 
-COPY --from=leonnicolas/boringtun:alpine /boringtun-cli /usr/local/sbin/boringtun
+# Copy boringtun
+COPY --from=boringtun-builder /usr/local/cargo/bin/boringtun-cli /usr/local/sbin/boringtun
 
 # Expose Ports
 EXPOSE 51820/udp