feat: build target for each binary

Dockerfile

@@ -2,8 +2,12 @@
 # This is loosely based on `docker init`'s rust template.
 # For a completely clean build, run something like this:
 # ```
-# docker build --build-arg=PROFILE=dev --build-arg=ENTRYPOINT=leader --no-cache
+# docker build --build-arg=PROFILE=dev --no-cache
 # ```
+#
+# There is a build target[^1] for each artifact we want.
+#
+# [^1]: https://docs.docker.com/build/building/multi-stage/
 
 #############
 # Build stage
@@ -71,10 +75,10 @@ find "/artifacts/$SUBDIR" \
 
 EOF
 
-##################
-# Final executable
-##################
-FROM debian:bullseye-slim AS final
+##########################
+# Base for the final image
+##########################
+FROM debian:bullseye-slim AS base
 
 # Install runtime dependencies.
 RUN apt-get update && apt-get install -y \
@@ -84,23 +88,6 @@ RUN apt-get update && apt-get install -y \
     tini \
     && rm -rf /var/lib/apt/lists/*
 
-COPY --from=build /output/* /usr/local/bin/
-RUN <<EOF
-set -eux
-: smoke test executables
-find /usr/local/bin -type f -executable -print0 \
-    | xargs --null --replace --verbose tini -- {} --help
-EOF
-
-# can't refer to docker args in an ENTRYPOINT directive, so go through a symlink
-ARG ENTRYPOINT
-RUN ln --symbolic --verbose -- "$(which ${ENTRYPOINT})" /entrypoint
-ENTRYPOINT [ "tini", "--", "/entrypoint" ]
-
-# TODO(0xaatif): https://github.com/0xPolygonZero/zk_evm/issues/356
-#                this is bad practice
-COPY .env /
-
 # Create a non-privileged user that the app will run under.
 # See https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#user
 ARG UID=10001
@@ -114,3 +101,22 @@ RUN adduser \
     user
 USER user
 
+####################################
+# Final executables with entrypoints
+####################################
+FROM base AS leader
+
+# TODO(0xaatif): https://github.com/0xPolygonZero/zk_evm/issues/356
+#                this is bad practice
+COPY .env /
+
+COPY --from=build /output/leader /usr/local/bin/
+COPY --from=build /output/rpc /usr/local/bin/
+RUN leader --help && rpc --help
+ENTRYPOINT [ "tini", "--", "leader" ]
+
+FROM base AS worker
+
+COPY --from=build /output/worker /usr/local/bin/
+RUN worker --help
+ENTRYPOINT [ "tini", "--", "worker" ]