Workflow multiline

.ci/containers/go-plus/Dockerfile

@@ -1,5 +1,25 @@
-from golang:1.19-bullseye as resource
+# Stage 1: Download go module cache for builds
+FROM golang:1.19-bullseye AS builder
+ENV GOCACHE=/go/cache
+
+RUN apt-get update && apt-get install -y unzip
+WORKDIR /app1
+# Add the source code and build
+ADD "https://github.com/GoogleCloudPlatform/magic-modules/archive/refs/heads/main.zip" source.zip
+RUN unzip source.zip && rm source.zip
+WORKDIR /app1/magic-modules-main/.ci/magician
+# Build the binary (we won't use it in the final image, but it's cached)
+RUN go build -o /dev/null .
+
+# Stage 2: Creating the final image
+FROM golang:1.19-bullseye
 SHELL ["/bin/bash", "-c"]
+ENV GOCACHE=/go/cache
+
+# Copy Go dependencies and Go build cache
+COPY --from=builder /go/pkg/mod /go/pkg/mod
+COPY --from=builder /go/cache /go/cache
+
 # Set up Github SSH cloning.
 RUN ssh-keyscan github.com >> /known_hosts
 RUN echo "UserKnownHostsFile /known_hosts" >> /etc/ssh/ssh_config