From 8a3a23131da8e8795c417690f7353f3c173b9238 Mon Sep 17 00:00:00 2001
From: Andrea Spadaccini <andrea.spadaccini@microsoft.com>
Date: Thu, 7 Jul 2022 14:58:40 +0200
Subject: [PATCH] feat(test): improve test Dockerfile

Install cURL if needed, and use a multi-stage build to have a cleaner image.
---
 test/Dockerfile | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/test/Dockerfile b/test/Dockerfile
index 8ba3278..14b9606 100644
--- a/test/Dockerfile
+++ b/test/Dockerfile
@@ -1,7 +1,8 @@
+# syntax=docker/dockerfile:1
 # Dockerfile to test the library with multiple versions of PowerShell >= 7.
 #
 # Example run (from repo root):
-# > $version="7.1.5"; docker build -f .\test\docker\Dockerfile . -t powershell-featureflags-test:$version --build-arg VERSION=$version --build-arg UBUNTU_VERSION=18.04 && docker run powershell-featureflags-test:$version
+# PS > $version="7.1.5"; docker build -f .\test\docker\Dockerfile . -t powershell-featureflags-test:$version --build-arg VERSION=$version --build-arg UBUNTU_VERSION=18.04 && docker run powershell-featureflags-test:$version
 
 ARG VERSION=7.2.5
 ARG UBUNTU_VERSION=16.04
@@ -11,16 +12,20 @@ FROM mcr.microsoft.com/powershell:${VERSION}-ubuntu-${UBUNTU_VERSION}
 #
 # Not using the dotnet SDK images because they bring their own powershell,
 # see for example https://github.com/dotnet/dotnet-docker/blob/main/src/sdk/6.0/focal/amd64/Dockerfile.
+# For some reason, docker images for Powershell 6 don't have curl.
 ENV DOTNET_SDK_VERSION=6.0.301 
-RUN curl -fSL --output dotnet.tar.gz https://dotnetcli.azureedge.net/dotnet/Sdk/$DOTNET_SDK_VERSION/dotnet-sdk-$DOTNET_SDK_VERSION-linux-x64.tar.gz
-RUN mkdir -p /usr/share/dotnet
-RUN tar -oxzf dotnet.tar.gz -C /usr/share/dotnet
-RUN rm dotnet.tar.gz
-RUN ln -s /usr/share/dotnet/dotnet /usr/bin/dotnet
+RUN if ! command -v curl &> /dev/null; then apt-get update; apt-get install -y curl; fi \
+    && curl -fSL --output dotnet.tar.gz https://dotnetcli.azureedge.net/dotnet/Sdk/$DOTNET_SDK_VERSION/dotnet-sdk-$DOTNET_SDK_VERSION-linux-x64.tar.gz \
+    && mkdir -p /usr/share/dotnet \
+    && tar -oxzf dotnet.tar.gz -C /usr/share/dotnet
 
+FROM mcr.microsoft.com/powershell:${VERSION}-ubuntu-${UBUNTU_VERSION}
+# Copy the dotnet installation.
+COPY --from=0 /usr/share/dotnet /usr/share/dotnet
+RUN ln -s /usr/share/dotnet/dotnet /usr/bin/dotnet
 # Copy the application code.
 WORKDIR /app
 COPY . .
 
 # Restore dependencies and run tests.
-CMD pwsh tools/restore.ps1; pwsh tools/run-tests.ps1
\ No newline at end of file
+CMD pwsh tools/restore.ps1; pwsh tools/run-tests.ps1