Optimize size with multi stage build

Dockerfile

@@ -1,50 +1,58 @@
+FROM alpine:3.21.3 AS build
+
+# set version label
+ARG WEBAPP_VERSION
+
+RUN apk add --no-cache \
+    bash \
+    busybox \
+    curl \
+    git \
+    jq \
+    npm && \
+    mkdir /app && \
+    if [ -z ${WEBAPP_VERSION+x} ]; then \
+        WEBAPP_VERSION=$(curl -sX GET "https://api.github.com/repos/netbootxyz/webapp/releases/latest" \
+        | awk '/tag_name/{print $4;exit}' FS='[""]'); \
+    fi && \
+    curl -o /tmp/webapp.tar.gz -L \
+        "https://github.com/netbootxyz/webapp/archive/${WEBAPP_VERSION}.tar.gz" && \
+    tar xf /tmp/webapp.tar.gz -C /app/ --strip-components=1 && \
+    npm install --prefix /app && \
+    rm -rf /tmp/*
+
 FROM alpine:3.21.3
 
 # set version label
 ARG BUILD_DATE
 ARG VERSION
-ARG WEBAPP_VERSION
 
 LABEL build_version="netboot.xyz version: ${VERSION} Build-date: ${BUILD_DATE}"
 LABEL maintainer="antonym"
-LABEL org.opencontainers.image.description netboot.xyz official docker container - Your favorite operating systems in one place. A network-based bootable operating system installer based on iPXE.
+LABEL org.opencontainers.image.description="netboot.xyz official docker container - Your favorite operating systems in one place. A network-based bootable operating system installer based on iPXE."
 
-RUN \
- apk add --no-cache \
-   bash \
-   busybox \
-   curl \
-   envsubst \
-   git \
-   jq \
-   nghttp2-dev \
-   nginx \
-   nodejs \
-   shadow \
-   sudo \
-   supervisor \
-   syslog-ng \
-   tar \
-   dnsmasq && \
- apk add --no-cache --virtual=build-dependencies \
-   npm && \
- groupmod -g 1000 users && \
- useradd -u 911 -U -d /config -s /bin/false nbxyz && \
- usermod -G users nbxyz && \
- mkdir /app \
-       /config \
-       /defaults && \
- if [ -z ${WEBAPP_VERSION+x} ]; then \
-        WEBAPP_VERSION=$(curl -sX GET "https://api.github.com/repos/netbootxyz/webapp/releases/latest" \
-        | awk '/tag_name/{print $4;exit}' FS='[""]'); \
- fi && \
- curl -o /tmp/webapp.tar.gz -L \
-        "https://github.com/netbootxyz/webapp/archive/${WEBAPP_VERSION}.tar.gz" && \
- tar xf /tmp/webapp.tar.gz -C \
-        /app/ --strip-components=1 && \
- npm install --prefix /app && \
- apk del --purge build-dependencies && \
- rm -rf /tmp/*
+RUN apk add --no-cache \
+    bash \
+    busybox \
+    curl \
+    dnsmasq \
+    envsubst \
+    git \
+    jq \
+    nghttp2-dev \
+    nginx \
+    nodejs \
+    shadow \
+    sudo \
+    supervisor \
+    syslog-ng \
+    tar && \
+    groupmod -g 1000 users && \
+    useradd -u 911 -U -d /config -s /bin/false nbxyz && \
+    usermod -G users nbxyz && \
+    mkdir /app /config /defaults
+
+COPY --from=build /app /app
 
 ENV TFTPD_OPTS=''
 ENV NGINX_PORT='80'