Function dockerfile 

pub fn dockerfile(d: &Deployment, source: &str, rust: &str) -> String

The container image, as a multi-stage build: builder stages that hold the toolchain (BUILDER_STAGES) and a runtime that holds the binary, the layer and nothing else. The runtime carries no compiler, no cargo registry, no repository history and no shell history — what is not copied in cannot leak out. rust is the exact version the builder pins, from builder_rust.