Add Alpine Linux support (#6367)

sys/sysctl header is not available in musl-libc based systems and system calls are available without any header inclusion. I have ported the cmake test from CoreFX repo (https://github.com/dotnet/corefx/blob/431475b8/src/Native/Unix/configure.cmake#L560).

Progress towards: #4605

src/libpsl-native/src/CMakeLists.txt

@@ -1,3 +1,5 @@
+include(CheckIncludeFiles)
+
 add_library(psl-native SHARED
   getstat.cpp
   getpwuid.cpp
@@ -24,4 +26,12 @@ add_library(psl-native SHARED
   createprocess.cpp
   nativesyslog.cpp)
 
+check_include_files(
+    "sys/types.h;sys/sysctl.h"
+    HAVE_SYS_SYSCTL_H)
+
+configure_file(
+    ${CMAKE_CURRENT_SOURCE_DIR}/pal_config.h.in
+    ${CMAKE_CURRENT_BINARY_DIR}/pal_config.h)
+
 target_include_directories(psl-native PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

src/libpsl-native/src/getppid.cpp

@@ -1,11 +1,15 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+#include "pal_config.h"
 #include "getppid.h"
 
 #include <sys/user.h>
 #include <sys/param.h>
+
+#if HAVE_SYS_SYSCTL_H
 #include <sys/sysctl.h>
+#endif
 
 //! @brief GetPPid returns the parent process id for a process
 //!

src/libpsl-native/src/getuserfrompid.cpp

@@ -2,6 +2,7 @@
 // Licensed under the MIT License.
 
 #include "pal.h"
+#include "pal_config.h"
 #include "getfileowner.h"
 #include "getpwuid.h"
 #include "getuserfrompid.h"
@@ -9,7 +10,10 @@
 #include <string>
 #include <sstream>
 #include <errno.h>
+
+#if HAVE_SYS_SYSCTL_H
 #include <sys/sysctl.h>
+#endif
 
 char* GetUserFromPid(pid_t pid)
 {

src/libpsl-native/src/pal_config.h.in

@@ -0,0 +1,3 @@
+#pragma once
+
+#cmakedefine01 HAVE_SYS_SYSCTL_H

tools/releaseBuild/Images/microsoft_powershell_alpine3/Dockerfile

@@ -0,0 +1,10 @@
+# Docker image file that describes an Centos7 image with PowerShell installed from Microsoft YUM Repo
+
+FROM microsoft/dotnet:2.1-sdk-alpine
+LABEL maintainer="PowerShell Team <powershellteam@hotmail.com>" 
+
+# Install dependencies and clean up
+RUN apk update \
+    && apk add cmake clang build-base git bash
+
+COPY build-and-run-pwsh.sh /

tools/releaseBuild/Images/microsoft_powershell_alpine3/build-and-run-pwsh.sh

@@ -0,0 +1,93 @@
+#!/bin/sh
+
+repoRoot=$1
+destination=$2
+releaseTag=$3
+
+# in Alpine, the currently supported architectures are:
+
+# x86_64
+# x86
+# aarch64
+# armhf
+# ppc64le
+# s390x
+
+# from https://pkgs.alpinelinux.org/packages (Arch dropdown menu)
+
+arch=`uname -m`
+
+case $arch in
+    x86_64)
+        arch=x64
+        ;;
+    aarch64)
+        arch=arm64
+        ;;
+    armhf)
+        arch=arm
+        ;;
+    *)
+        echo "Error: Unsupported OS architecture $arch detected"
+        exit 1
+        ;;
+esac
+
+# set variables depending on releaseTag
+# remove v from release tag (v3.5 => 3.5)
+if [ "${releaseTag:0:1}" = "v" ]; then
+  releaseTag=${releaseTag:1}
+  tarName=$destination/powershell-$releaseTag-alpine.3-$arch.tar.gz
+  dotnetArguments=/p:ReleaseTag=$releaseTag;
+else
+  tarName=$destination/powershell-alpine.3-$arch.tar.gz
+fi
+
+# Build libpsl-native
+cd $repoRoot/src/libpsl-native
+
+cmake -DCMAKE_BUILD_TYPE=Debug .
+make -j
+
+# Restore packages
+cd ../..
+dotnet restore $dotnetArguments
+
+# Add telemetry file
+touch DELETE_ME_TO_DISABLE_CONSOLEHOST_TELEMETRY
+
+# run ResGen
+cd src/ResGen
+dotnet run
+
+# Create typeCatalog
+cd ..
+targetFile="Microsoft.PowerShell.SDK/obj/Microsoft.PowerShell.SDK.csproj.TypeCatalog.targets"
+cat > $targetFile <<-"EOF"
+<Project>
+  <Target Name="_GetDependencies"
+          DependsOnTargets="ResolveAssemblyReferencesDesignTime">
+    <ItemGroup>
+      <_RefAssemblyPath Include="%(_ReferencesFromRAR.ResolvedPath)%3B" Condition=" '%(_ReferencesFromRAR.Type)' == 'assembly' And '%(_ReferencesFromRAR.PackageName)' != 'Microsoft.Management.Infrastructure' " />
+    </ItemGroup>
+    <WriteLinesToFile File="$(_DependencyFile)" Lines="@(_RefAssemblyPath)" Overwrite="true" />
+  </Target>
+</Project>
+EOF
+
+dotnet msbuild Microsoft.PowerShell.SDK/Microsoft.PowerShell.SDK.csproj /t:_GetDependencies "/property:DesignTimeBuild=true;_DependencyFile=$(pwd)/TypeCatalogGen/powershell.inc" /nologo
+
+cd TypeCatalogGen
+dotnet run ../System.Management.Automation/CoreCLR/CorePsTypeCatalog.cs powershell.inc
+
+# build PowerShell
+cd ../powershell-unix
+dotnet publish --configuration Linux --runtime linux-x64 $dotnetArguments
+
+# add libpsl-native to build
+mv libpsl-native.so bin/Linux/netcoreapp2.0/linux-x64
+
+# tar build for output
+cd bin/Linux/netcoreapp2.0/linux-x64
+
+tar -czvf $tarName .

tools/releaseBuild/build.json

@@ -228,6 +228,15 @@
         "DockerFile": "./tools/releaseBuild/Images/microsoft_powershell_centos7/Dockerfile",
         "DockerImageName": "ps-centos-7",
         "BinaryBucket": "release"
+    },
+    {
+        "Name": "alpine.3",
+        "RepoDestinationPath": "/PowerShell",
+        "BuildCommand": "/build-and-run-pwsh.sh _RepoDestinationPath_ _DockerVolume_ _ReleaseTag_",
+        "AdditionalContextFiles" :[ "./tools/releaseBuild/Images/microsoft_powershell_alpine3/build-and-run-pwsh.sh"],
+        "DockerFile": "./tools/releaseBuild/Images/microsoft_powershell_alpine3/Dockerfile",
+        "DockerImageName": "ps-alpine-3",
+        "BinaryBucket": "release"
     }
   ]
 }