fix(content): harden Docker practice guide

04_image/demo/buildkit/Dockerfile.buildkit

@@ -1,4 +1,4 @@
-# syntax = docker/dockerfile:experimental
+# syntax=docker/dockerfile:1
 
 FROM node:alpine as builder
 
@@ -6,24 +6,16 @@ WORKDIR /app
 
 COPY package.json /app/
 
-RUN --mount=type=cache,target=/app/node_modules,id=my_app_npm_module,sharing=locked \
-    --mount=type=cache,target=/root/.npm,id=npm_cache \
-        npm i --registry=https://registry.npmmirror.com
+RUN --mount=type=cache,target=/root/.npm,id=npm_cache \
+        npm install --registry=https://registry.npmmirror.com
 
 COPY src /app/src
 
-RUN --mount=type=cache,target=/app/node_modules,id=my_app_npm_module,sharing=locked \
-# --mount=type=cache,target=/app/dist,id=my_app_dist,sharing=locked \
-        npm run build
+RUN npm run build
 
 FROM nginx:alpine
 
-# COPY --from=builder /app/dist /app/dist
-
-# 为了更直观的说明 from 和 source 指令，这里使用 RUN 指令
-RUN --mount=type=cache,target=/tmp/dist,from=builder,source=/app/dist \
-    # --mount=type=cache,target/tmp/dist,from=my_app_dist,sharing=locked \
-    mkdir -p /app/dist && cp -r /tmp/dist/* /app/dist
+COPY --from=builder /app/dist /app/dist
 
 RUN --mount=type=bind,from=php:alpine,source=/usr/local/bin/docker-php-entrypoint,target=/docker-php-entrypoint \
         cat /docker-php-entrypoint
@@ -32,6 +24,6 @@ RUN --mount=type=tmpfs,target=/temp \
         mount | grep /temp
 
 RUN --mount=type=secret,id=aws,target=/root/.aws/credentials \
-        cat /root/.aws/credentials
+        test -s /root/.aws/credentials && echo "credentials mounted"
 
 # docker build -t test --secret id=aws,src=$PWD/aws.txt --progress=plain -f Dockerfile.buildkit .