Optimize the multi-stage build docker image

Signed-off-by: Boris Bera <bbera@coveo.com>

docs/deployment/docker.md

@@ -165,53 +165,64 @@ RUN find packages \! -name "package.json" -mindepth 2 -maxdepth 2 -exec rm -rf {
 # Stage 2 - Install dependencies and build packages
 FROM node:16-bullseye-slim AS build
 
-WORKDIR /app
-COPY --from=packages /app .
-
 # install sqlite3 dependencies
-RUN apt-get update && \
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
+    --mount=type=cache,target=/var/lib/apt,sharing=locked \
+    apt-get update && \
     apt-get install -y --no-install-recommends libsqlite3-dev python3 build-essential && \
     yarn config set python /usr/bin/python3
 
-RUN yarn install --frozen-lockfile --network-timeout 600000 && rm -rf "$(yarn cache dir)"
+USER node
+WORKDIR /app
 
-COPY . .
+COPY --from=packages --chown=node:node /app .
+
+# Stop cypress from downloading it's massive binary.
+ENV CYPRESS_INSTALL_BINARY=0
+RUN --mount=type=cache,target=/home/node/.cache/yarn,sharing=locked,uid=1000,gid=1000 \
+    yarn install --frozen-lockfile --network-timeout 600000
+
+COPY --chown=node:node . .
 
 RUN yarn tsc
 RUN yarn --cwd packages/backend build
 # If you have not yet migrated to package roles, use the following command instead:
 # RUN yarn --cwd packages/backend backstage-cli backend:bundle --build-dependencies
 
+RUN mkdir packages/backend/dist/skeleton packages/backend/dist/bundle \
+    && tar xzf packages/backend/dist/skeleton.tar.gz -C packages/backend/dist/skeleton \
+    && tar xzf packages/backend/dist/bundle.tar.gz -C packages/backend/dist/bundle
+
 # Stage 3 - Build the actual backend image and install production dependencies
 FROM node:16-bullseye-slim
 
 # Install sqlite3 dependencies. You can skip this if you don't use sqlite3 in the image,
 # in which case you should also move better-sqlite3 to "devDependencies" in package.json.
-RUN apt-get update && \
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
+    --mount=type=cache,target=/var/lib/apt,sharing=locked \
+    apt-get update && \
     apt-get install -y --no-install-recommends libsqlite3-dev python3 build-essential && \
-    rm -rf /var/lib/apt/lists/* && \
     yarn config set python /usr/bin/python3
 
 # From here on we use the least-privileged `node` user to run the backend.
 USER node
 WORKDIR /app
 
-# This switches many Node.js dependencies to production mode.
-ENV NODE_ENV production
-
 # Copy the install dependencies from the build stage and context
-COPY --from=build --chown=node:node /app/yarn.lock /app/package.json /app/packages/backend/dist/skeleton.tar.gz ./
-RUN tar xzf skeleton.tar.gz && rm skeleton.tar.gz
+COPY --from=build --chown=node:node /app/yarn.lock /app/package.json /app/packages/backend/dist/skeleton/ ./
 
-RUN yarn install --frozen-lockfile --production --network-timeout 600000 && rm -rf "$(yarn cache dir)"
+RUN --mount=type=cache,target=/home/node/.cache/yarn,sharing=locked,uid=1000,gid=1000 \
+    yarn install --frozen-lockfile --production --network-timeout 600000
 
 # Copy the built packages from the build stage
-COPY --from=build --chown=node:node /app/packages/backend/dist/bundle.tar.gz .
-RUN tar xzf bundle.tar.gz && rm bundle.tar.gz
+COPY --from=build --chown=node:node /app/packages/backend/dist/bundle/ ./
 
 # Copy any other files that we need at runtime
 COPY --chown=node:node app-config.yaml ./
 
+# This switches many Node.js dependencies to production mode.
+ENV NODE_ENV production
+
 CMD ["node", "packages/backend", "--config", "app-config.yaml"]
 ```
 
@@ -227,6 +238,7 @@ however ignore any existing build output or dependencies on the host. For our
 new `.dockerignore`, replace the contents of your existing one with this:
 
 ```text
+dist-types
 node_modules
 packages/*/dist
 packages/*/node_modules