chore: usage and code example

Author: joseluisq

Makefile

@@ -1,12 +1,3 @@
-run:
-	docker run --rm \
-        -v "${PWD}/sample":/home/rust/sample \
-        -w /home/rust/sample \
-        rust-linux-darwin-builder:latest \
-        cargo build --release --target x86_64-unknown-linux-musl && \
-        /home/rust/sample/target/x86_64-unknown-linux-musl/release/helloworld
-.PHONY: run
-
 build:
-	docker build -t rust-linux-darwin-builder:latest -f Dockerfile .
+	docker build -t joseluisq/rust-linux-darwin-builder:1.40.0 -f Dockerfile .
 .PHONY: build

README.md

@@ -1,6 +1,6 @@
-# Rust Linux / Darwin Builder
+# Rust Linux / Darwin Builder [![Docker Image](https://img.shields.io/docker/pulls/joseluisq/rust-linux-darwin-builder.svg)](https://hub.docker.com/r/joseluisq/rust-linux-darwin-builder/)
 
-> A Docker image for compiling [Rust](https://www.rust-lang.org/) binaries for __Linux__ (static binaries via [musl-libc / musl-gcc](https://doc.rust-lang.org/edition-guide/rust-2018/platform-and-target-support/musl-support-for-fully-static-binaries.html)) and __macOS__ (via [osxcross](https://github.com/tpoechtrager/osxcross)).
+> Use same Docker image for compiling [Rust](https://www.rust-lang.org/) programs for Linux ([musl libc](https://doc.rust-lang.org/edition-guide/rust-2018/platform-and-target-support/musl-support-for-fully-static-binaries.html)) & macOS ([osxcross](https://github.com/tpoechtrager/osxcross)).
 
 ## Overview
 
@@ -14,22 +14,26 @@ __x86_64-unknown-linux-musl__
 
 ```sh
 docker run --rm \
-    -v "$PWD/sample":/home/rust/sample \
-    -w /home/rust/sample \
+    --user rust:rust \
+    --volume "${PWD}/sample":/home/rust/sample \
+    --workdir /home/rust/sample \
     joseluisq/rust-linux-darwin-builder:1.40.0 \
-    cargo build --release --target x86_64-unknown-linux-musl
+    sh -c "cargo build --release"
 ```
 
 __x86_64-apple-darwin__
 
 ```sh
 docker run --rm \
-    -v "$PWD/sample":/home/rust/sample \
-    -w /home/rust/sample \
+    --user rust:rust \
+    --volume "${PWD}/sample":/home/rust/sample \
+    --workdir /home/rust/sample \
     joseluisq/rust-linux-darwin-builder:1.40.0 \
-    cargo build --release --target x86_64-apple-darwin
+    sh -c "cargo build --release --target x86_64-apple-darwin"
 ```
 
+*__Note:__ This example is also available under [./sample](./sample) directory.*
+
 ### Dockerfile
 
 You can also use the image as a base for your own Dockerfile:

sample/Makefile

@@ -0,0 +1,19 @@
+linux:
+	@docker run --rm \
+				--name rust_builder_linux \
+				--user rust:rust \
+				--volume "${PWD}/sample":/home/rust/sample \
+				--workdir /home/rust/sample \
+				joseluisq/rust-linux-darwin-builder:1.40.0 \
+				sh -c "cargo build --release"
+.PHONY: linux
+
+darwin:
+	@docker run --rm \
+				--name rust_builder_darwin \
+				--user rust:rust \
+				--volume "${PWD}/sample":/home/rust/sample \
+				--workdir /home/rust/sample \
+				joseluisq/rust-linux-darwin-builder:1.40.0 \
+				sh -c "cargo build --release --target x86_64-apple-darwin"
+.PHONY: darwin