[Packaging] Optimize Dockerfile build

Dockerfile

@@ -1,11 +1,49 @@
+# syntax=docker/dockerfile:1.4
 #---------------------------------------------------------------------------------------------
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License. See License.txt in the project root for license information.
 #---------------------------------------------------------------------------------------------
 
 ARG PYTHON_VERSION="3.11"
 
-FROM python:${PYTHON_VERSION}-alpine
+FROM python:${PYTHON_VERSION}-alpine AS base
+
+# We don't use openssl (3.0) for now. We only install it so that users can use it.
+# libintl and icu-libs - required by azure devops artifact (az extension add --name azure-devops)
+RUN apk add --no-cache \
+    bash bash-completion openssh-keygen ca-certificates openssl \
+    curl jq git perl zip \
+    libintl icu-libs libc6-compat \
+ && update-ca-certificates
+
+
+FROM base AS builder
+
+ARG JP_VERSION="0.2.1"
+# bash gcc make openssl-dev libffi-dev musl-dev - dependencies required for CLI
+RUN apk add --no-cache --virtual .build-deps gcc make openssl-dev libffi-dev musl-dev linux-headers
+
+WORKDIR azure-cli
+COPY . /azure-cli
+
+# 1. Install azure-cli in /usr/local
+# 2. Run trim_sdk.py to clean up un-used py files: https://github.com/Azure/azure-cli/pull/25801
+# 3. Check that az and az.completion.sh can run
+# 4. Remove __pycache__. It is important that we run this at the end
+RUN ./scripts/install_full.sh
+RUN python3 ./scripts/trim_sdk.py
+RUN /usr/local/bin/az && bash -c "source /usr/local/bin/az.completion.sh"
+RUN find /usr/local/lib/python*/site-packages/azure -name __pycache__ | xargs rm -rf
+
+# Install jp tool
+RUN <<HERE
+  arch=$(arch | sed s/aarch64/arm64/ | sed s/x86_64/amd64/)
+  curl -L https://github.com/jmespath/jp/releases/download/${JP_VERSION}/jp-linux-${arch} -o /usr/local/bin/jp
+  chmod +x /usr/local/bin/jp
+HERE
+
+
+FROM base
 
 ARG CLI_VERSION
 
@@ -25,49 +63,11 @@ LABEL maintainer="Microsoft" \
       org.label-schema.vcs-url="https://github.com/Azure/azure-cli.git" \
       org.label-schema.docker.cmd="docker run -v \${HOME}/.azure:/root/.azure -it mcr.microsoft.com/azure-cli:$CLI_VERSION"
 
-# bash gcc make openssl-dev libffi-dev musl-dev - dependencies required for CLI
-# openssh - included for ssh-keygen
-# ca-certificates
-
-# curl - required for installing jp
-# jq - we include jq as a useful tool
-# pip wheel - required for CLI packaging
-# jmespath-terminal - we include jpterm as a useful tool
-# libintl and icu-libs - required by azure devops artifact (az extension add --name azure-devops)
-
-# We don't use openssl (3.0) for now. We only install it so that users can use it.
-RUN apk add --no-cache bash openssh ca-certificates jq curl openssl perl git zip \
- && apk add --no-cache --virtual .build-deps gcc make openssl-dev libffi-dev musl-dev linux-headers \
- && apk add --no-cache libintl icu-libs libc6-compat \
- && apk add --no-cache bash-completion \
- && update-ca-certificates
-
-ARG JP_VERSION="0.2.1"
-
-RUN arch=$(arch | sed s/aarch64/arm64/ | sed s/x86_64/amd64/) && curl -L https://github.com/jmespath/jp/releases/download/${JP_VERSION}/jp-linux-$arch -o /usr/local/bin/jp \
- && chmod +x /usr/local/bin/jp
-
-WORKDIR azure-cli
-COPY . /azure-cli
-
-# 1. Build packages and store in tmp dir
-# 2. Install the cli and the other command modules that weren't included
-RUN ./scripts/install_full.sh && python ./scripts/trim_sdk.py \
- && cat /azure-cli/az.completion > ~/.bashrc \
- && runDeps="$( \
-    scanelf --needed --nobanner --recursive /usr/local \
-        | awk '{ gsub(/,/, "\nso:", $2); print "so:" $2 }' \
-        | sort -u \
-        | xargs -r apk info --installed \
-        | sort -u \
-    )" \
- && apk add --virtual .rundeps $runDeps
-
-WORKDIR /
-
-# Remove CLI source code from the final image and normalize line endings.
-RUN rm -rf ./azure-cli && \
-    dos2unix /root/.bashrc /usr/local/bin/az
+RUN --mount=from=builder,target=/mnt <<HERE
+  cd /mnt/usr/local
+  cp -ru . /usr/local/
+  ln -s /usr/local/bin/az.completion.sh /etc/profile.d/
+HERE
 
 ENV AZ_INSTALLER=DOCKER
 CMD bash