Avoid redownloading the shared runtime when it's already installed. (#121)

Fixes #119

build/KoreBuild.ps1

@@ -35,8 +35,12 @@ if ($env:KOREBUILD_DOTNET_SHARED_RUNTIME_CHANNEL)
     $dotnetSharedRuntimeChannel = $env:KOREBUILD_DOTNET_SHARED_RUNTIME_CHANNEL 
 }
 
+$dotnetLocalInstallFolder = $env:DOTNET_INSTALL_DIR
+if (!$dotnetLocalInstallFolder)
+{
+    $dotnetLocalInstallFolder = "$env:LOCALAPPDATA\Microsoft\dotnet\"
+}
  
-$dotnetLocalInstallFolder = "$env:LOCALAPPDATA\Microsoft\dotnet\"
 $newPath = "$dotnetLocalInstallFolder;$env:PATH"
 if ($env:KOREBUILD_SKIP_RUNTIME_INSTALL -eq "1") 
 {
@@ -47,7 +51,12 @@ if ($env:KOREBUILD_SKIP_RUNTIME_INSTALL -eq "1")
 else
 {
     & "$koreBuildFolder\dotnet\dotnet-install.ps1" -Channel $dotnetChannel -Version $dotnetVersion -Architecture x64
+    # Avoid redownloading the CLI if it's already installed.
+    $sharedRuntimePath = [IO.Path]::Combine($dotnetLocalInstallFolder, 'shared', 'Microsoft.NETCore.App', $dotnetSharedRuntimeVersion)
+    if (!(Test-Path $sharedRuntimePath))
+    {
         & "$koreBuildFolder\dotnet\dotnet-install.ps1" -Channel $dotnetSharedRuntimeChannel -SharedRuntime -Version $dotnetSharedRuntimeVersion -Architecture x64
+    }
 }
 if (!($env:Path.Split(';') -icontains $dotnetLocalInstallFolder))
 {

build/KoreBuild.sh

@@ -52,12 +52,16 @@ if [ ! -z "$KOREBUILD_SKIP_RUNTIME_INSTALL" ]; then
 else
     # Need to set this variable because by default the install script
     # requires sudo
-    export DOTNET_INSTALL_DIR=~/.dotnet
+    [ -z "$DOTNET_INSTALL_DIR" ] && DOTNET_INSTALL_DIR=~/.dotnet
+    export DOTNET_INSTALL_DIR=$DOTNET_INSTALL_DIR
     export KOREBUILD_FOLDER="$(dirname $koreBuildFolder)"
     chmod +x $koreBuildFolder/dotnet/dotnet-install.sh
 
     $koreBuildFolder/dotnet/dotnet-install.sh --channel $KOREBUILD_DOTNET_CHANNEL --version $KOREBUILD_DOTNET_VERSION
+    sharedRuntimePath="$DOTNET_INSTALL_DIR/shared/Microsoft.NETCore.App/$KOREBUILD_DOTNET_SHARED_RUNTIME_VERSION"
+    if [ -d "$sharedRuntimePath" ]; then
         $koreBuildFolder/dotnet/dotnet-install.sh --shared-runtime --channel $KOREBUILD_DOTNET_SHARED_RUNTIME_CHANNEL --version $KOREBUILD_DOTNET_SHARED_RUNTIME_VERSION
+    fi
 
     # Add .NET installation directory to the path if it isn't yet included.
     [[ ":$PATH:" != *":$DOTNET_INSTALL_DIR:"* ]] && export PATH="$DOTNET_INSTALL_DIR:$PATH"