Update:

* Fix base64 decode for circle ci
* Add readme

Author: OpenGG

.circleci/config.yml

@@ -13,6 +13,6 @@ jobs:
           name: Build and push Docker image
           command: |
             docker build -t opengg/rust-wasm .
-            echo "$DOCKER_PASSWORD_BASE64"|base64 --decode|docker login -u "$DOCKER_USER" --password-stdin
+            echo "$DOCKER_PASSWORD_BASE64"|base64 -d|docker login -u "$DOCKER_USER" --password-stdin
             docker push opengg/rust-wasm
 

README.md

@@ -1,2 +1,30 @@
 # docker-rust-wasm
 Minimal docker image for rust to wasm compilation
+
+Based on [Compiling Rust to Wasm manually with the LLVM wasm-backend (without Emscripten)](https://gist.github.com/LukasKalbertodt/821ab8b85a25f4c54544cc43bed2c39f)
+
+## Usage
+
+First, prepare your rust source file, e.g. `add.rs`.
+
+```rust
+#[no_mangle]
+pub fn add_twenty_seven(n: i32) -> i32 {
+  n + 27
+}
+```
+
+Then run this docker image, compiling rust into wasm.
+
+```bash
+docker run -it --rm -v "$(pwd):/work" opengg/rust-wasm add.rs
+```
+
+## Run an interactive shell
+
+Alternatively, you can run an interactive shell, exploring
+this docker image freely.
+
+```bash
+docker run -it --rm -v "$(pwd):/work" --entrypoint bash opengg/rust-wasm
+```