tweak Dockerfile: cache dependencies

.dockerignore

@@ -1,6 +1,9 @@
+.DS_Store
 /.fleet
+/.github
 /.idea
 /.run
 /elf
 /target
 /tmp
+Dockerfile

.github/workflows/build-image.yml

@@ -2,7 +2,7 @@ name: Create and publish a Docker image
 
 on:
   push:
-    branches: ['release']
+    branches: ['release', 'stage']
     tags: ['v*']
 
 # Defines two custom environment variables for the workflow. These are used for the Container registry domain, and a name for the Docker image that this workflow builds.

.gitignore

@@ -1,5 +1,6 @@
-/target
+.DS_Store
 /.idea
-/elf/
-/tmp/
-
+/.run
+/elf
+/target
+/tmp

Dockerfile

@@ -1,12 +1,16 @@
+# syntax=docker/dockerfile:1-labs
+
 FROM rust:alpine AS base
-RUN apk add --no-cache musl-dev openssl-dev pkgconfig openssl-libs-static
+RUN apk add --no-cache musl-dev openssl-dev openssl-libs-static pkgconfig
+WORKDIR /app
 
 FROM base AS builder
-WORKDIR /app
+COPY --exclude=./examples/** --parents ./**/Cargo.* ./rust-toolchain.toml ./
+RUN mkdir -p ./src ./charms-data/src ./charms-sdk/src ./charms-spell-checker/src && \
+    touch -d '2000-01-01 00:00' src/main.rs src/lib.rs charms-data/src/lib.rs charms-sdk/src/lib.rs charms-spell-checker/src/lib.rs
+RUN cargo build --release --locked --bin charms --keep-going || true
 COPY . .
-RUN --mount=type=cache,target=/app/target \
-    --mount=type=cache,from=base,source=/usr/local/rustup,target=/usr/local/rustup \
-    cargo install --locked --path .
+RUN cargo install --locked --offline --path . --bin charms
 
 FROM alpine AS runtime
 COPY --from=builder /usr/local/cargo/bin/charms /usr/local/bin