Use a separate stage in Dockerfile to build frontend code

Author: Kobzol

Dockerfile

@@ -1,3 +1,10 @@
+FROM node:18 as frontend
+
+COPY ./site ./site
+RUN cd site/frontend && npm ci
+RUN cd site/frontend && npm run check
+RUN cd site/frontend && npm run build
+
 FROM ubuntu:20.04 as build
 
 RUN apt-get update -y && \
@@ -16,19 +23,13 @@ RUN apt-get update -y && \
 RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- \
     --default-toolchain stable --profile minimal -y
 
-RUN curl -fsSL https://deb.nodesource.com/setup_lts.x | bash - && \
-  apt-get install -y nodejs
-
 COPY ./Cargo.lock ./Cargo.lock
 COPY ./Cargo.toml ./Cargo.toml
 COPY ./collector ./collector
 COPY ./database ./database
 COPY ./intern ./intern
 COPY ./site ./site
-
-RUN cd site/frontend && npm ci
-RUN cd site/frontend && npm run check
-RUN cd site/frontend && npm run build
+COPY --from=frontend ./site/frontend/dist ./site/frontend/dist
 
 RUN bash -c 'source $HOME/.cargo/env && cargo build --release -p site'
 RUN bash -c 'source $HOME/.cargo/env && cargo build --release --bin postgres-to-sqlite'