From c6fce3a672d86e9e54d46cf35a346417f05694f6 Mon Sep 17 00:00:00 2001
From: Danny McCormick <damccorm@microsoft.com>
Date: Thu, 20 Jun 2019 16:17:52 -0400
Subject: [PATCH] Feedback

---
 __tests__/installer.test.ts  |  48 ++++
 externals/install-dotnet.ps1 | 309 +++++++++++++++------
 externals/install-dotnet.sh  | 508 ++++++++++++++++++++++++-----------
 src/installer.ts             |  26 +-
 4 files changed, 629 insertions(+), 262 deletions(-)

diff --git a/__tests__/installer.test.ts b/__tests__/installer.test.ts
index 9f0952a..2988f8f 100644
--- a/__tests__/installer.test.ts
+++ b/__tests__/installer.test.ts
@@ -2,6 +2,7 @@ import io = require('@actions/io');
 import fs = require('fs');
 import os = require('os');
 import path = require('path');
+import httpClient = require('typed-rest-client/HttpClient');
 
 const toolDir = path.join(__dirname, 'runner', 'tools');
 const tempDir = path.join(__dirname, 'runner', 'temp');
@@ -71,8 +72,55 @@ describe('installer tests', () => {
     expect(thrown).toBe(true);
     return;
   });
+
+  it('Uses an up to date bash download script', async () => {
+    var httpCallbackClient = new httpClient.HttpClient(
+      'setup-dotnet-test',
+      [],
+      {}
+    );
+    const response: httpClient.HttpClientResponse = await httpCallbackClient.get(
+      'https://dot.net/v1/dotnet-install.sh'
+    );
+    const upToDateContents: string = await response.readBody();
+    const currentContents: string = fs
+      .readFileSync(
+        path.join(__dirname, '..', 'externals', 'install-dotnet.sh')
+      )
+      .toString();
+    expect(normalizeFileContents(currentContents)).toBe(
+      normalizeFileContents(upToDateContents)
+    );
+  });
+
+  it('Uses an up to date powershell download script', async () => {
+    var httpCallbackClient = new httpClient.HttpClient(
+      'setup-dotnet-test',
+      [],
+      {}
+    );
+    const response: httpClient.HttpClientResponse = await httpCallbackClient.get(
+      'https://dot.net/v1/dotnet-install.ps1'
+    );
+    const upToDateContents: string = await response.readBody();
+    const currentContents: string = fs
+      .readFileSync(
+        path.join(__dirname, '..', 'externals', 'install-dotnet.ps1')
+      )
+      .toString();
+    expect(normalizeFileContents(currentContents)).toBe(
+      normalizeFileContents(upToDateContents)
+    );
+  });
 });
 
+function normalizeFileContents(contents: string): string {
+  return contents
+    .trim()
+    .replace(new RegExp('\r\n', 'g'), '\n')
+    .replace(new RegExp('\r', 'g'), '\n');
+}
+
 async function getDotnet(version: string): Promise<void> {
   const dotnetInstaller = new installer.DotnetCoreInstaller(version);
   await dotnetInstaller.installDotnet();
diff --git a/externals/install-dotnet.ps1 b/externals/install-dotnet.ps1
index 8540453..f17bd85 100644
--- a/externals/install-dotnet.ps1
+++ b/externals/install-dotnet.ps1
@@ -15,9 +15,10 @@
     - Current - most current release
     - LTS - most current supported release
     - 2-part version in a format A.B - represents a specific release
-          examples: 2.0; 1.0
+          examples: 2.0, 1.0
     - Branch name
-          examples: release/2.0.0; Master
+          examples: release/2.0.0, Master
+    Note: The version parameter overrides the channel parameter.
 .PARAMETER Version
     Default: latest
     Represents a build version on specific channel. Possible values:
@@ -25,17 +26,26 @@
     - coherent - most latest coherent build on specific channel
           coherent applies only to SDK downloads
     - 3-part version in a format A.B.C - represents specific version of build
-          examples: 2.0.0-preview2-006120; 1.1.0
+          examples: 2.0.0-preview2-006120, 1.1.0
 .PARAMETER InstallDir
     Default: %LocalAppData%\Microsoft\dotnet
     Path to where to install dotnet. Note that binaries will be placed directly in a given directory.
 .PARAMETER Architecture
     Default: <auto> - this value represents currently running OS architecture
     Architecture of dotnet binaries to be installed.
-    Possible values are: <auto>, x64 and x86
+    Possible values are: <auto>, amd64, x64, x86, arm64, arm
 .PARAMETER SharedRuntime
+    This parameter is obsolete and may be removed in a future version of this script.
+    The recommended alternative is '-Runtime dotnet'.
+
     Default: false
-    Installs just the shared runtime bits, not the entire SDK
+    Installs just the shared runtime bits, not the entire SDK.
+    This is equivalent to specifying `-Runtime dotnet`.
+.PARAMETER Runtime
+    Installs just a shared runtime, not the entire SDK.
+    Possible values:
+        - dotnet     - the Microsoft.NETCore.App shared runtime
+        - aspnetcore - the Microsoft.AspNetCore.App shared runtime
 .PARAMETER DryRun
     If set it will not perform installation but instead display what command line to use to consistently install
     currently requested version of dotnet cli. In example if you specify version 'latest' it will display a link
@@ -49,15 +59,23 @@
 .PARAMETER AzureFeed
     Default: https://dotnetcli.azureedge.net/dotnet
     This parameter typically is not changed by the user.
-    It allows to change URL for the Azure feed used by this installer.
+    It allows changing the URL for the Azure feed used by this installer.
 .PARAMETER UncachedFeed
     This parameter typically is not changed by the user.
-    It allows to change URL for the Uncached feed used by this installer.
+    It allows changing the URL for the Uncached feed used by this installer.
+.PARAMETER FeedCredential
+    Used as a query string to append to the Azure feed.
+    It allows changing the URL to use non-public blob storage accounts.
 .PARAMETER ProxyAddress
     If set, the installer will use the proxy when making web requests
 .PARAMETER ProxyUseDefaultCredentials
     Default: false
     Use default credentials, when using proxy address.
+.PARAMETER SkipNonVersionedFiles
+    Default: false
+    Skips installing non-versioned files if they already exist, such as dotnet.exe.
+.PARAMETER NoCdn
+    Disable downloading from the Azure CDN, and use the uncached feed directly.
 #>
 [cmdletbinding()]
 param(
@@ -65,27 +83,41 @@ param(
    [string]$Version="Latest",
    [string]$InstallDir="<auto>",
    [string]$Architecture="<auto>",
+   [ValidateSet("dotnet", "aspnetcore", IgnoreCase = $false)]
+   [string]$Runtime,
+   [Obsolete("This parameter may be removed in a future version of this script. The recommended alternative is '-Runtime dotnet'.")]
    [switch]$SharedRuntime,
    [switch]$DryRun,
    [switch]$NoPath,
    [string]$AzureFeed="https://dotnetcli.azureedge.net/dotnet",
    [string]$UncachedFeed="https://dotnetcli.blob.core.windows.net/dotnet",
+   [string]$FeedCredential,
    [string]$ProxyAddress,
-   [switch]$ProxyUseDefaultCredentials
+   [switch]$ProxyUseDefaultCredentials,
+   [switch]$SkipNonVersionedFiles,
+   [switch]$NoCdn
 )
 
 Set-StrictMode -Version Latest
 $ErrorActionPreference="Stop"
 $ProgressPreference="SilentlyContinue"
 
+if ($NoCdn) {
+    $AzureFeed = $UncachedFeed
+}
+
 $BinFolderRelativePath=""
 
+if ($SharedRuntime -and (-not $Runtime)) {
+    $Runtime = "dotnet"
+}
+
 # example path with regex: shared/1.0.0-beta-12345/somepath
 $VersionRegEx="/\d+\.\d+[^/]+/"
-$OverrideNonVersionedFiles=$true
+$OverrideNonVersionedFiles = !$SkipNonVersionedFiles
 
 function Say($str) {
-    Write-Output "dotnet-install: $str"
+    Write-Host "dotnet-install: $str"
 }
 
 function Say-Verbose($str) {
@@ -120,11 +152,10 @@ function Invoke-With-Retry([ScriptBlock]$ScriptBlock, [int]$MaxAttempts = 3, [in
 function Get-Machine-Architecture() {
     Say-Invocation $MyInvocation
 
-    # possible values: AMD64, IA64, x86
+    # possible values: amd64, x64, x86, arm64, arm
     return $ENV:PROCESSOR_ARCHITECTURE
 }
 
-# TODO: Architecture and CLIArchitecture should be unified
 function Get-CLIArchitecture-From-Architecture([string]$Architecture) {
     Say-Invocation $MyInvocation
 
@@ -132,18 +163,27 @@ function Get-CLIArchitecture-From-Architecture([string]$Architecture) {
         { $_ -eq "<auto>" } { return Get-CLIArchitecture-From-Architecture $(Get-Machine-Architecture) }
         { ($_ -eq "amd64") -or ($_ -eq "x64") } { return "x64" }
         { $_ -eq "x86" } { return "x86" }
-        default { throw "Architecture not supported. If you think this is a bug, please report it at https://github.com/dotnet/cli/issues" }
+        { $_ -eq "arm" } { return "arm" }
+        { $_ -eq "arm64" } { return "arm64" }
+        default { throw "Architecture not supported. If you think this is a bug, report it at https://github.com/dotnet/cli/issues" }
     }
 }
 
+# The version text returned from the feeds is a 1-line or 2-line string:
+# For the SDK and the dotnet runtime (2 lines):
+# Line 1: # commit_hash
+# Line 2: # 4-part version
+# For the aspnetcore runtime (1 line):
+# Line 1: # 4-part version
 function Get-Version-Info-From-Version-Text([string]$VersionText) {
     Say-Invocation $MyInvocation
 
-    $Data = @($VersionText.Split([char[]]@(), [StringSplitOptions]::RemoveEmptyEntries));
+    $Data = -split $VersionText
 
-    $VersionInfo = @{}
-    $VersionInfo.CommitHash = $Data[0].Trim()
-    $VersionInfo.Version = $Data[1].Trim()
+    $VersionInfo = @{
+        CommitHash = $(if ($Data.Count -gt 1) { $Data[0] })
+        Version = $Data[-1] # last line is always the version number.
+    }
     return $VersionInfo
 }
 
@@ -168,33 +208,39 @@ function GetHTTPResponse([Uri] $Uri)
             # HttpClient is used vs Invoke-WebRequest in order to support Nano Server which doesn't support the Invoke-WebRequest cmdlet.
             Load-Assembly -Assembly System.Net.Http
 
-            if(-not $ProxyAddress)
-            {
-                # Despite no proxy being explicitly specified, we may still be behind a default proxy
-                $DefaultProxy = [System.Net.WebRequest]::DefaultWebProxy;
-                if($DefaultProxy -and (-not $DefaultProxy.IsBypassed($Uri))){
-                    $ProxyAddress =  $DefaultProxy.GetProxy($Uri).OriginalString
-                    $ProxyUseDefaultCredentials = $true
+            if(-not $ProxyAddress) {
+                try {
+                    # Despite no proxy being explicitly specified, we may still be behind a default proxy
+                    $DefaultProxy = [System.Net.WebRequest]::DefaultWebProxy;
+                    if($DefaultProxy -and (-not $DefaultProxy.IsBypassed($Uri))) {
+                        $ProxyAddress = $DefaultProxy.GetProxy($Uri).OriginalString
+                        $ProxyUseDefaultCredentials = $true
+                    }
+                } catch {
+                    # Eat the exception and move forward as the above code is an attempt
+                    #    at resolving the DefaultProxy that may not have been a problem.
+                    $ProxyAddress = $null
+                    Say-Verbose("Exception ignored: $_.Exception.Message - moving forward...")
                 }
             }
 
-            if($ProxyAddress){
+            if($ProxyAddress) {
                 $HttpClientHandler = New-Object System.Net.Http.HttpClientHandler
                 $HttpClientHandler.Proxy =  New-Object System.Net.WebProxy -Property @{Address=$ProxyAddress;UseDefaultCredentials=$ProxyUseDefaultCredentials}
                 $HttpClient = New-Object System.Net.Http.HttpClient -ArgumentList $HttpClientHandler
-            } 
+            }
             else {
+
                 $HttpClient = New-Object System.Net.Http.HttpClient
             }
             # Default timeout for HttpClient is 100s.  For a 50 MB download this assumes 500 KB/s average, any less will time out
-            # 10 minutes allows it to work over much slower connections.
-            $HttpClient.Timeout = New-TimeSpan -Minutes 10
-            $Response = $HttpClient.GetAsync($Uri).Result
-            if (($Response -eq $null) -or (-not ($Response.IsSuccessStatusCode)))
-            {
+            # 20 minutes allows it to work over much slower connections.
+            $HttpClient.Timeout = New-TimeSpan -Minutes 20
+            $Response = $HttpClient.GetAsync("${Uri}${FeedCredential}").Result
+            if (($Response -eq $null) -or (-not ($Response.IsSuccessStatusCode))) {
+                 # The feed credential is potentially sensitive info. Do not log FeedCredential to console output.
                 $ErrorMsg = "Failed to download $Uri."
-                if ($Response -ne $null)
-                {
+                if ($Response -ne $null) {
                     $ErrorMsg += "  $Response"
                 }
 
@@ -208,7 +254,7 @@ function GetHTTPResponse([Uri] $Uri)
                 $HttpClient.Dispose()
             }
         }
-    })  
+    })
 }
 
 
@@ -216,10 +262,13 @@ function Get-Latest-Version-Info([string]$AzureFeed, [string]$Channel, [bool]$Co
     Say-Invocation $MyInvocation
 
     $VersionFileUrl = $null
-    if ($SharedRuntime) {
+    if ($Runtime -eq "dotnet") {
         $VersionFileUrl = "$UncachedFeed/Runtime/$Channel/latest.version"
     }
-    else {
+    elseif ($Runtime -eq "aspnetcore") {
+        $VersionFileUrl = "$UncachedFeed/aspnetcore/Runtime/$Channel/latest.version"
+    }
+    elseif (-not $Runtime) {
         if ($Coherent) {
             $VersionFileUrl = "$UncachedFeed/Sdk/$Channel/latest.coherent.version"
         }
@@ -227,12 +276,19 @@ function Get-Latest-Version-Info([string]$AzureFeed, [string]$Channel, [bool]$Co
             $VersionFileUrl = "$UncachedFeed/Sdk/$Channel/latest.version"
         }
     }
-    
-    $Response = GetHTTPResponse -Uri $VersionFileUrl
+    else {
+        throw "Invalid value for `$Runtime"
+    }
+    try {
+        $Response = GetHTTPResponse -Uri $VersionFileUrl
+    }
+    catch {
+        throw "Could not resolve version information."
+    }
     $StringContent = $Response.Content.ReadAsStringAsync().Result
 
     switch ($Response.Content.Headers.ContentType) {
-        { ($_ -eq "application/octet-stream") } { $VersionText = [Text.Encoding]::UTF8.GetString($StringContent) }
+        { ($_ -eq "application/octet-stream") } { $VersionText = $StringContent }
         { ($_ -eq "text/plain") } { $VersionText = $StringContent }
         { ($_ -eq "text/plain; charset=UTF-8") } { $VersionText = $StringContent }
         default { throw "``$Response.Content.Headers.ContentType`` is an unknown .version file content type." }
@@ -260,32 +316,41 @@ function Get-Specific-Version-From-Version([string]$AzureFeed, [string]$Channel,
     }
 }
 
-function Get-Download-Link([string]$AzureFeed, [string]$Channel, [string]$SpecificVersion, [string]$CLIArchitecture) {
+function Get-Download-Link([string]$AzureFeed, [string]$SpecificVersion, [string]$CLIArchitecture) {
     Say-Invocation $MyInvocation
-    
-    if ($SharedRuntime) {
+
+    if ($Runtime -eq "dotnet") {
         $PayloadURL = "$AzureFeed/Runtime/$SpecificVersion/dotnet-runtime-$SpecificVersion-win-$CLIArchitecture.zip"
     }
-    else {
+    elseif ($Runtime -eq "aspnetcore") {
+        $PayloadURL = "$AzureFeed/aspnetcore/Runtime/$SpecificVersion/aspnetcore-runtime-$SpecificVersion-win-$CLIArchitecture.zip"
+    }
+    elseif (-not $Runtime) {
         $PayloadURL = "$AzureFeed/Sdk/$SpecificVersion/dotnet-sdk-$SpecificVersion-win-$CLIArchitecture.zip"
     }
+    else {
+        throw "Invalid value for `$Runtime"
+    }
 
-    Say-Verbose "Constructed primary payload URL: $PayloadURL"
+    Say-Verbose "Constructed primary named payload URL: $PayloadURL"
 
     return $PayloadURL
 }
 
-function Get-LegacyDownload-Link([string]$AzureFeed, [string]$Channel, [string]$SpecificVersion, [string]$CLIArchitecture) {
+function Get-LegacyDownload-Link([string]$AzureFeed, [string]$SpecificVersion, [string]$CLIArchitecture) {
     Say-Invocation $MyInvocation
-    
-    if ($SharedRuntime) {
+
+    if (-not $Runtime) {
+        $PayloadURL = "$AzureFeed/Sdk/$SpecificVersion/dotnet-dev-win-$CLIArchitecture.$SpecificVersion.zip"
+    }
+    elseif ($Runtime -eq "dotnet") {
         $PayloadURL = "$AzureFeed/Runtime/$SpecificVersion/dotnet-win-$CLIArchitecture.$SpecificVersion.zip"
     }
     else {
-        $PayloadURL = "$AzureFeed/Sdk/$SpecificVersion/dotnet-dev-win-$CLIArchitecture.$SpecificVersion.zip"
+        return $null
     }
 
-    Say-Verbose "Constructed legacy payload URL: $PayloadURL"
+    Say-Verbose "Constructed legacy named payload URL: $PayloadURL"
 
     return $PayloadURL
 }
@@ -314,7 +379,7 @@ function Get-Version-Info-From-Version-File([string]$InstallRoot, [string]$Relat
 
     $VersionFile = Join-Path -Path $InstallRoot -ChildPath $RelativePathToVersionFile
     Say-Verbose "Local version file: $VersionFile"
-    
+
     if (Test-Path $VersionFile) {
         $VersionText = cat $VersionFile
         Say-Verbose "Local version file text: $VersionText"
@@ -328,7 +393,7 @@ function Get-Version-Info-From-Version-File([string]$InstallRoot, [string]$Relat
 
 function Is-Dotnet-Package-Installed([string]$InstallRoot, [string]$RelativePathToPackage, [string]$SpecificVersion) {
     Say-Invocation $MyInvocation
-    
+
     $DotnetPackagePath = Join-Path -Path $InstallRoot -ChildPath $RelativePathToPackage | Join-Path -ChildPath $SpecificVersion
     Say-Verbose "Is-Dotnet-Package-Installed: Path to a package: $DotnetPackagePath"
     return Test-Path $DotnetPackagePath -PathType Container
@@ -346,13 +411,13 @@ function Get-Path-Prefix-With-Version($path) {
     if ($match.Success) {
         return $entry.FullName.Substring(0, $match.Index + $match.Length)
     }
-    
+
     return $null
 }
 
 function Get-List-Of-Directories-And-Versions-To-Unpack-From-Dotnet-Package([System.IO.Compression.ZipArchive]$Zip, [string]$OutPath) {
     Say-Invocation $MyInvocation
-    
+
     $ret = @()
     foreach ($entry in $Zip.Entries) {
         $dir = Get-Path-Prefix-With-Version $entry.FullName
@@ -363,12 +428,12 @@ function Get-List-Of-Directories-And-Versions-To-Unpack-From-Dotnet-Package([Sys
             }
         }
     }
-    
+
     $ret = $ret | Sort-Object | Get-Unique
-    
+
     $values = ($ret | foreach { "$_" }) -join ";"
     Say-Verbose "Directories to unpack: $values"
-    
+
     return $ret
 }
 
@@ -392,9 +457,9 @@ function Extract-Dotnet-Package([string]$ZipPath, [string]$OutPath) {
     Set-Variable -Name Zip
     try {
         $Zip = [System.IO.Compression.ZipFile]::OpenRead($ZipPath)
-        
+
         $DirectoriesToUnpack = Get-List-Of-Directories-And-Versions-To-Unpack-From-Dotnet-Package -Zip $Zip -OutPath $OutPath
-        
+
         foreach ($entry in $Zip.Entries) {
             $PathWithVersion = Get-Path-Prefix-With-Version $entry.FullName
             if (($PathWithVersion -eq $null) -Or ($DirectoriesToUnpack -contains $PathWithVersion)) {
@@ -415,11 +480,23 @@ function Extract-Dotnet-Package([string]$ZipPath, [string]$OutPath) {
     }
 }
 
-function DownloadFile([Uri]$Uri, [string]$OutPath) {
+function DownloadFile($Source, [string]$OutPath) {
+    if ($Source -notlike "http*") {
+        #  Using System.IO.Path.GetFullPath to get the current directory
+        #    does not work in this context - $pwd gives the current directory
+        if (![System.IO.Path]::IsPathRooted($Source)) {
+            $Source = $(Join-Path -Path $pwd -ChildPath $Source)
+        }
+        $Source = Get-Absolute-Path $Source
+        Say "Copying file from $Source to $OutPath"
+        Copy-Item $Source $OutPath
+        return
+    }
+
     $Stream = $null
 
     try {
-        $Response = GetHTTPResponse -Uri $Uri
+        $Response = GetHTTPResponse -Uri $Source
         $Stream = $Response.Content.ReadAsStreamAsync().Result
         $File = [System.IO.File]::Create($OutPath)
         $Stream.CopyTo($File)
@@ -435,8 +512,13 @@ function DownloadFile([Uri]$Uri, [string]$OutPath) {
 function Prepend-Sdk-InstallRoot-To-Path([string]$InstallRoot, [string]$BinFolderRelativePath) {
     $BinPath = Get-Absolute-Path $(Join-Path -Path $InstallRoot -ChildPath $BinFolderRelativePath)
     if (-Not $NoPath) {
-        Say "Adding to current process PATH: `"$BinPath`". Note: This change will not be visible if PowerShell was run as a child process."
-        $env:path = "$BinPath;" + $env:path
+        $SuffixedBinPath = "$BinPath;"
+        if (-Not $env:path.Contains($SuffixedBinPath)) {
+            Say "Adding to current process PATH: `"$BinPath`". Note: This change will not be visible if PowerShell was run as a child process."
+            $env:path = $SuffixedBinPath + $env:path
+        } else {
+            Say-Verbose "Current process PATH already contains `"$BinPath`""
+        }
     }
     else {
         Say "Binaries of dotnet can be found in $BinPath"
@@ -445,24 +527,55 @@ function Prepend-Sdk-InstallRoot-To-Path([string]$InstallRoot, [string]$BinFolde
 
 $CLIArchitecture = Get-CLIArchitecture-From-Architecture $Architecture
 $SpecificVersion = Get-Specific-Version-From-Version -AzureFeed $AzureFeed -Channel $Channel -Version $Version
-$DownloadLink = Get-Download-Link -AzureFeed $AzureFeed -Channel $Channel -SpecificVersion $SpecificVersion -CLIArchitecture $CLIArchitecture
-$LegacyDownloadLink = Get-LegacyDownload-Link -AzureFeed $AzureFeed -Channel $Channel -SpecificVersion $SpecificVersion -CLIArchitecture $CLIArchitecture
-
-if ($DryRun) {
-    Say "Payload URLs:"
-    Say "Primary - $DownloadLink"
-    Say "Legacy - $LegacyDownloadLink"
-    Say "Repeatable invocation: .\$($MyInvocation.MyCommand) -Version $SpecificVersion -Channel $Channel -Architecture $CLIArchitecture -InstallDir $InstallDir"
-    exit 0
-}
+$DownloadLink = Get-Download-Link -AzureFeed $AzureFeed -SpecificVersion $SpecificVersion -CLIArchitecture $CLIArchitecture
+$LegacyDownloadLink = Get-LegacyDownload-Link -AzureFeed $AzureFeed -SpecificVersion $SpecificVersion -CLIArchitecture $CLIArchitecture
 
 $InstallRoot = Resolve-Installation-Path $InstallDir
 Say-Verbose "InstallRoot: $InstallRoot"
+$ScriptName = $MyInvocation.MyCommand.Name
 
-$IsSdkInstalled = Is-Dotnet-Package-Installed -InstallRoot $InstallRoot -RelativePathToPackage "sdk" -SpecificVersion $SpecificVersion
-Say-Verbose ".NET SDK installed? $IsSdkInstalled"
-if ($IsSdkInstalled) {
-    Say ".NET SDK version $SpecificVersion is already installed."
+if ($DryRun) {
+    Say "Payload URLs:"
+    Say "Primary named payload URL: $DownloadLink"
+    if ($LegacyDownloadLink) {
+        Say "Legacy named payload URL: $LegacyDownloadLink"
+    }
+    $RepeatableCommand = ".\$ScriptName -Version `"$SpecificVersion`" -InstallDir `"$InstallRoot`" -Architecture `"$CLIArchitecture`""
+    if ($Runtime -eq "dotnet") {
+       $RepeatableCommand+=" -Runtime `"dotnet`""
+    }
+    elseif ($Runtime -eq "aspnetcore") {
+       $RepeatableCommand+=" -Runtime `"aspnetcore`""
+    }
+    foreach ($key in $MyInvocation.BoundParameters.Keys) {
+        if (-not (@("Architecture","Channel","DryRun","InstallDir","Runtime","SharedRuntime","Version") -contains $key)) {
+            $RepeatableCommand+=" -$key `"$($MyInvocation.BoundParameters[$key])`""
+        }
+    }
+    Say "Repeatable invocation: $RepeatableCommand"
+    exit 0
+}
+
+if ($Runtime -eq "dotnet") {
+    $assetName = ".NET Core Runtime"
+    $dotnetPackageRelativePath = "shared\Microsoft.NETCore.App"
+}
+elseif ($Runtime -eq "aspnetcore") {
+    $assetName = "ASP.NET Core Runtime"
+    $dotnetPackageRelativePath = "shared\Microsoft.AspNetCore.App"
+}
+elseif (-not $Runtime) {
+    $assetName = ".NET Core SDK"
+    $dotnetPackageRelativePath = "sdk"
+}
+else {
+    throw "Invalid value for `$Runtime"
+}
+
+#  Check if the SDK version is already installed.
+$isAssetInstalled = Is-Dotnet-Package-Installed -InstallRoot $InstallRoot -RelativePathToPackage $dotnetPackageRelativePath -SpecificVersion $SpecificVersion
+if ($isAssetInstalled) {
+    Say "$assetName version $SpecificVersion is already installed."
     Prepend-Sdk-InstallRoot-To-Path -InstallRoot $InstallRoot -BinFolderRelativePath $BinFolderRelativePath
     exit 0
 }
@@ -470,34 +583,56 @@ if ($IsSdkInstalled) {
 New-Item -ItemType Directory -Force -Path $InstallRoot | Out-Null
 
 $installDrive = $((Get-Item $InstallRoot).PSDrive.Name);
-Write-Output "${installDrive}:";
-$free = Get-CimInstance -Class win32_logicaldisk | where Deviceid -eq "${installDrive}:"
-if ($free.Freespace / 1MB -le 100 ) {
+$diskInfo = Get-PSDrive -Name $installDrive
+if ($diskInfo.Free / 1MB -le 100) {
     Say "There is not enough disk space on drive ${installDrive}:"
     exit 0
 }
 
-$ZipPath = [System.IO.Path]::GetTempFileName()
+$ZipPath = [System.IO.Path]::combine([System.IO.Path]::GetTempPath(), [System.IO.Path]::GetRandomFileName())
 Say-Verbose "Zip path: $ZipPath"
+
+$DownloadFailed = $false
 Say "Downloading link: $DownloadLink"
 try {
-    DownloadFile -Uri $DownloadLink -OutPath $ZipPath
+    DownloadFile -Source $DownloadLink -OutPath $ZipPath
 }
 catch {
     Say "Cannot download: $DownloadLink"
-    $DownloadLink = $LegacyDownloadLink
-    $ZipPath = [System.IO.Path]::GetTempFileName()
-    Say-Verbose "Legacy zip path: $ZipPath"
-    Say "Downloading legacy link: $DownloadLink"
-    DownloadFile -Uri $DownloadLink -OutPath $ZipPath
+    if ($LegacyDownloadLink) {
+        $DownloadLink = $LegacyDownloadLink
+        $ZipPath = [System.IO.Path]::combine([System.IO.Path]::GetTempPath(), [System.IO.Path]::GetRandomFileName())
+        Say-Verbose "Legacy zip path: $ZipPath"
+        Say "Downloading legacy link: $DownloadLink"
+        try {
+            DownloadFile -Source $DownloadLink -OutPath $ZipPath
+        }
+        catch {
+            Say "Cannot download: $DownloadLink"
+            $DownloadFailed = $true
+        }
+    }
+    else {
+        $DownloadFailed = $true
+    }
+}
+
+if ($DownloadFailed) {
+    throw "Could not find/download: `"$assetName`" with version = $SpecificVersion`nRefer to: https://aka.ms/dotnet-os-lifecycle for information on .NET Core support"
 }
 
 Say "Extracting zip from $DownloadLink"
 Extract-Dotnet-Package -ZipPath $ZipPath -OutPath $InstallRoot
 
+#  Check if the SDK version is now installed; if not, fail the installation.
+$isAssetInstalled = Is-Dotnet-Package-Installed -InstallRoot $InstallRoot -RelativePathToPackage $dotnetPackageRelativePath -SpecificVersion $SpecificVersion
+if (!$isAssetInstalled) {
+    throw "`"$assetName`" with version = $SpecificVersion failed to install with an unknown error."
+}
+
 Remove-Item $ZipPath
 
 Prepend-Sdk-InstallRoot-To-Path -InstallRoot $InstallRoot -BinFolderRelativePath $BinFolderRelativePath
 
 Say "Installation finished"
-exit 0
\ No newline at end of file
+exit 0
diff --git a/externals/install-dotnet.sh b/externals/install-dotnet.sh
index 0ea08a7..2217d47 100644
--- a/externals/install-dotnet.sh
+++ b/externals/install-dotnet.sh
@@ -22,7 +22,7 @@ exec 3>&1
 
 # Setup some colors to use. These need to work in fairly limited shells, like the Ubuntu Docker container where there are only 8 colors.
 # See if stdout is a terminal
-if [ -t 1 ]; then
+if [ -t 1 ] && command -v tput > /dev/null; then
     # see if it supports colors
     ncolors=$(tput colors)
     if [ -n "$ncolors" ] && [ $ncolors -ge 8 ]; then
@@ -39,6 +39,10 @@ if [ -t 1 ]; then
     fi
 fi
 
+say_warning() {
+    printf "%b\n" "${yellow:-}dotnet_install: Warning: $1${normal:-}"
+}
+
 say_err() {
     printf "%b\n" "${red:-}dotnet_install: Error: $1${normal:-}" >&2
 }
@@ -55,7 +59,10 @@ say_verbose() {
     fi
 }
 
-get_os_download_name_from_platform() {
+# This platform list is finite - if the SDK/Runtime has supported Linux distribution-specific assets,
+#   then and only then should the Linux distribution appear in this list.
+# Adding a Linux distribution to this list does not imply distribution-specific support.
+get_legacy_os_name_from_platform() {
     eval $invocation
 
     platform="$1"
@@ -68,6 +75,10 @@ get_os_download_name_from_platform() {
             echo "debian"
             return 0
             ;;
+        "debian.9")
+            echo "debian.9"
+            return 0
+            ;;
         "fedora.23")
             echo "fedora.23"
             return 0
@@ -76,6 +87,14 @@ get_os_download_name_from_platform() {
             echo "fedora.24"
             return 0
             ;;
+        "fedora.27")
+            echo "fedora.27"
+            return 0
+            ;;
+        "fedora.28")
+            echo "fedora.28"
+            return 0
+            ;;
         "opensuse.13.2")
             echo "opensuse.13.2"
             return 0
@@ -84,6 +103,10 @@ get_os_download_name_from_platform() {
             echo "opensuse.42.1"
             return 0
             ;;
+        "opensuse.42.3")
+            echo "opensuse.42.3"
+            return 0
+            ;;
         "rhel.7"*)
             echo "rhel"
             return 0
@@ -100,6 +123,10 @@ get_os_download_name_from_platform() {
             echo "ubuntu.16.10"
             return 0
             ;;
+        "ubuntu.18.04")
+            echo "ubuntu.18.04"
+            return 0
+            ;;
         "alpine.3.4.3")
             echo "alpine"
             return 0
@@ -108,6 +135,30 @@ get_os_download_name_from_platform() {
     return 1
 }
 
+get_linux_platform_name() {
+    eval $invocation
+
+    if [ -n "$runtime_id" ]; then
+        echo "${runtime_id%-*}"
+        return 0
+    else
+        if [ -e /etc/os-release ]; then
+            . /etc/os-release
+            echo "$ID.$VERSION_ID"
+            return 0
+        elif [ -e /etc/redhat-release ]; then
+            local redhatRelease=$(</etc/redhat-release)
+            if [[ $redhatRelease == "CentOS release 6."* || $redhatRelease == "Red Hat Enterprise Linux Server release 6."* ]]; then
+                echo "rhel.6"
+                return 0
+            fi
+        fi
+    fi
+
+    say_verbose "Linux specific platform name and version could not be detected: UName = $uname"
+    return 1
+}
+
 get_current_os_name() {
     eval $invocation
 
@@ -115,18 +166,30 @@ get_current_os_name() {
     if [ "$uname" = "Darwin" ]; then
         echo "osx"
         return 0
-    else
-        if [ "$uname" = "Linux" ]; then
+    elif [ "$uname" = "FreeBSD" ]; then
+        echo "freebsd"
+        return 0        
+    elif [ "$uname" = "Linux" ]; then
+        local linux_platform_name
+        linux_platform_name="$(get_linux_platform_name)" || { echo "linux" && return 0 ; }
+
+        if [[ $linux_platform_name == "rhel.6" ]]; then
+            echo $linux_platform_name
+            return 0
+        elif [[ $linux_platform_name == alpine* ]]; then
+            echo "linux-musl"
+            return 0
+        else
             echo "linux"
             return 0
         fi
     fi
 
-    say_err "OS name could not be detected: $ID.$VERSION_ID"
+    say_err "OS name could not be detected: UName = $uname"
     return 1
 }
 
-get_distro_specific_os_name() {
+get_legacy_os_name() {
     eval $invocation
 
     local uname=$(uname)
@@ -134,12 +197,12 @@ get_distro_specific_os_name() {
         echo "osx"
         return 0
     elif [ -n "$runtime_id" ]; then
-        echo $(get_os_download_name_from_platform "${runtime_id%-*}" || echo "${runtime_id%-*}")
+        echo $(get_legacy_os_name_from_platform "${runtime_id%-*}" || echo "${runtime_id%-*}")
         return 0
     else
         if [ -e /etc/os-release ]; then
             . /etc/os-release
-            os=$(get_os_download_name_from_platform "$ID.$VERSION_ID" || echo "")
+            os=$(get_legacy_os_name_from_platform "$ID.$VERSION_ID" || echo "")
             if [ -n "$os" ]; then
                 echo "$os"
                 return 0
@@ -147,7 +210,7 @@ get_distro_specific_os_name() {
         fi
     fi
 
-    say_verbose "Distribution specific OS name and version could not be detected: $ID.$VERSION_ID"
+    say_verbose "Distribution specific OS name and version could not be detected: UName = $uname"
     return 1
 }
 
@@ -177,27 +240,25 @@ check_min_reqs() {
 check_pre_reqs() {
     eval $invocation
 
-    local failing=false;
-
     if [ "${DOTNET_INSTALL_SKIP_PREREQS:-}" = "1" ]; then
         return 0
     fi
 
     if [ "$(uname)" = "Linux" ]; then
-        if ! [ -x "$(command -v ldconfig)" ]; then
+        if [ ! -x "$(command -v ldconfig)" ]; then
             echo "ldconfig is not in PATH, trying /sbin/ldconfig."
             LDCONFIG_COMMAND="/sbin/ldconfig"
         else
             LDCONFIG_COMMAND="ldconfig"
         fi
 
-        [ -z "$($LDCONFIG_COMMAND -p | grep libunwind)" ] && say_err "Unable to locate libunwind. Install libunwind to continue" && failing=true
-        [ -z "$($LDCONFIG_COMMAND -p | grep libssl)" ] && say_err "Unable to locate libssl. Install libssl to continue" && failing=true
-        [ -z "$($LDCONFIG_COMMAND -p | grep libicu)" ] && say_err "Unable to locate libicu. Install libicu to continue" && failing=true
-    fi
+        local librarypath=${LD_LIBRARY_PATH:-}
+        LDCONFIG_COMMAND="$LDCONFIG_COMMAND -NXv ${librarypath//:/ }"
 
-    if [ "$failing" = true ]; then
-       return 1
+        [ -z "$($LDCONFIG_COMMAND 2>/dev/null | grep libunwind)" ] && say_warning "Unable to locate libunwind. Probable prerequisite missing; install libunwind."
+        [ -z "$($LDCONFIG_COMMAND 2>/dev/null | grep libssl)" ] && say_warning "Unable to locate libssl. Probable prerequisite missing; install libssl."
+        [ -z "$($LDCONFIG_COMMAND 2>/dev/null | grep libicu)" ] && say_warning "Unable to locate libicu. Probable prerequisite missing; install libicu."
+        [ -z "$($LDCONFIG_COMMAND 2>/dev/null | grep -F libcurl.so)" ] && say_warning "Unable to locate libcurl. Probable prerequisite missing; install libcurl."
     fi
 
     return 0
@@ -217,7 +278,7 @@ to_lowercase() {
 remove_trailing_slash() {
     #eval $invocation
 
-    local input=${1:-}
+    local input="${1:-}"
     echo "${input%/}"
     return 0
 }
@@ -227,7 +288,7 @@ remove_trailing_slash() {
 remove_beginning_slash() {
     #eval $invocation
 
-    local input=${1:-}
+    local input="${1:-}"
     echo "${input#/}"
     return 0
 }
@@ -244,8 +305,8 @@ combine_paths() {
         return 1
     fi
 
-    local root_path=$(remove_trailing_slash $1)
-    local child_path=$(remove_beginning_slash ${2:-})
+    local root_path="$(remove_trailing_slash "$1")"
+    local child_path="$(remove_beginning_slash "${2:-}")"
     say_verbose "combine_paths: root_path=$root_path"
     say_verbose "combine_paths: child_path=$child_path"
     echo "$root_path/$child_path"
@@ -255,7 +316,21 @@ combine_paths() {
 get_machine_architecture() {
     eval $invocation
 
-    # Currently the only one supported
+    if command -v uname > /dev/null; then
+        CPUName=$(uname -m)
+        case $CPUName in
+        armv7l)
+            echo "arm"
+            return 0
+            ;;
+        aarch64)
+            echo "arm64"
+            return 0
+            ;;
+        esac
+    fi
+
+    # Always default to 'x64'
     echo "x64"
     return 0
 }
@@ -265,46 +340,43 @@ get_machine_architecture() {
 get_normalized_architecture_from_architecture() {
     eval $invocation
 
-    local architecture=$(to_lowercase $1)
-    case $architecture in
+    local architecture="$(to_lowercase "$1")"
+    case "$architecture" in
         \<auto\>)
-            echo "$(get_normalized_architecture_from_architecture $(get_machine_architecture))"
+            echo "$(get_normalized_architecture_from_architecture "$(get_machine_architecture)")"
             return 0
             ;;
         amd64|x64)
             echo "x64"
             return 0
             ;;
-        x86)
-            say_err "Architecture \`x86\` currently not supported"
-            return 1
+        arm)
+            echo "arm"
+            return 0
+            ;;
+        arm64)
+            echo "arm64"
+            return 0
             ;;
     esac
 
-    say_err "Architecture \`$architecture\` not supported. If you think this is a bug, please report it at https://github.com/dotnet/cli/issues"
+    say_err "Architecture \`$architecture\` not supported. If you think this is a bug, report it at https://github.com/dotnet/cli/issues"
     return 1
 }
 
-# version_info is a conceptual two line string representing commit hash and 4-part version
-# format:
+# The version text returned from the feeds is a 1-line or 2-line string:
+# For the SDK and the dotnet runtime (2 lines):
 # Line 1: # commit_hash
 # Line 2: # 4-part version
+# For the aspnetcore runtime (1 line):
+# Line 1: # 4-part version
 
 # args:
 # version_text - stdin
 get_version_from_version_info() {
     eval $invocation
 
-    cat | tail -n 1
-    return 0
-}
-
-# args:
-# version_text - stdin
-get_commit_hash_from_version_info() {
-    eval $invocation
-
-    cat | head -n 1
+    cat | tail -n 1 | sed 's/\r$//'
     return 0
 }
 
@@ -315,11 +387,11 @@ get_commit_hash_from_version_info() {
 is_dotnet_package_installed() {
     eval $invocation
 
-    local install_root=$1
-    local relative_path_to_package=$2
-    local specific_version=${3//[$'\t\r\n']}
+    local install_root="$1"
+    local relative_path_to_package="$2"
+    local specific_version="${3//[$'\t\r\n']}"
 
-    local dotnet_package_path=$(combine_paths $(combine_paths $install_root $relative_path_to_package) $specific_version)
+    local dotnet_package_path="$(combine_paths "$(combine_paths "$install_root" "$relative_path_to_package")" "$specific_version")"
     say_verbose "is_dotnet_package_installed: dotnet_package_path=$dotnet_package_path"
 
     if [ -d "$dotnet_package_path" ]; then
@@ -333,27 +405,33 @@ is_dotnet_package_installed() {
 # azure_feed - $1
 # channel - $2
 # normalized_architecture - $3
+# coherent - $4
 get_latest_version_info() {
     eval $invocation
 
-    local azure_feed=$1
-    local channel=$2
-    local normalized_architecture=$3
-    local coherent=$4
+    local azure_feed="$1"
+    local channel="$2"
+    local normalized_architecture="$3"
+    local coherent="$4"
 
     local version_file_url=null
-    if [ "$shared_runtime" = true ]; then
+    if [[ "$runtime" == "dotnet" ]]; then
         version_file_url="$uncached_feed/Runtime/$channel/latest.version"
-    else
+    elif [[ "$runtime" == "aspnetcore" ]]; then
+        version_file_url="$uncached_feed/aspnetcore/Runtime/$channel/latest.version"
+    elif [ -z "$runtime" ]; then
         if [ "$coherent" = true ]; then
             version_file_url="$uncached_feed/Sdk/$channel/latest.coherent.version"
         else
             version_file_url="$uncached_feed/Sdk/$channel/latest.version"
         fi
+    else
+        say_err "Invalid value for \$runtime"
+        return 1
     fi
     say_verbose "get_latest_version_info: latest url: $version_file_url"
 
-    download $version_file_url
+    download "$version_file_url"
     return $?
 }
 
@@ -365,28 +443,28 @@ get_latest_version_info() {
 get_specific_version_from_version() {
     eval $invocation
 
-    local azure_feed=$1
-    local channel=$2
-    local normalized_architecture=$3
-    local version=$(to_lowercase $4)
+    local azure_feed="$1"
+    local channel="$2"
+    local normalized_architecture="$3"
+    local version="$(to_lowercase "$4")"
 
-    case $version in
+    case "$version" in
         latest)
             local version_info
-            version_info="$(get_latest_version_info $azure_feed $channel $normalized_architecture false)" || return 1
+            version_info="$(get_latest_version_info "$azure_feed" "$channel" "$normalized_architecture" false)" || return 1
             say_verbose "get_specific_version_from_version: version_info=$version_info"
             echo "$version_info" | get_version_from_version_info
             return 0
             ;;
         coherent)
             local version_info
-            version_info="$(get_latest_version_info $azure_feed $channel $normalized_architecture true)" || return 1
+            version_info="$(get_latest_version_info "$azure_feed" "$channel" "$normalized_architecture" true)" || return 1
             say_verbose "get_specific_version_from_version: version_info=$version_info"
             echo "$version_info" | get_version_from_version_info
             return 0
             ;;
         *)
-            echo $version
+            echo "$version"
             return 0
             ;;
     esac
@@ -400,19 +478,23 @@ get_specific_version_from_version() {
 construct_download_link() {
     eval $invocation
 
-    local azure_feed=$1
-    local channel=$2
-    local normalized_architecture=$3
-    local specific_version=${4//[$'\t\r\n']}
+    local azure_feed="$1"
+    local channel="$2"
+    local normalized_architecture="$3"
+    local specific_version="${4//[$'\t\r\n']}"
 
     local osname
-    osname=$(get_current_os_name) || return 1
+    osname="$(get_current_os_name)" || return 1
 
     local download_link=null
-    if [ "$shared_runtime" = true ]; then
+    if [[ "$runtime" == "dotnet" ]]; then
         download_link="$azure_feed/Runtime/$specific_version/dotnet-runtime-$specific_version-$osname-$normalized_architecture.tar.gz"
-    else
+    elif [[ "$runtime" == "aspnetcore" ]]; then
+        download_link="$azure_feed/aspnetcore/Runtime/$specific_version/aspnetcore-runtime-$specific_version-$osname-$normalized_architecture.tar.gz"
+    elif [ -z "$runtime" ]; then
         download_link="$azure_feed/Sdk/$specific_version/dotnet-sdk-$specific_version-$osname-$normalized_architecture.tar.gz"
+    else
+        return 1
     fi
 
     echo "$download_link"
@@ -427,19 +509,21 @@ construct_download_link() {
 construct_legacy_download_link() {
     eval $invocation
 
-    local azure_feed=$1
-    local channel=$2
-    local normalized_architecture=$3
-    local specific_version=${4//[$'\t\r\n']}
+    local azure_feed="$1"
+    local channel="$2"
+    local normalized_architecture="$3"
+    local specific_version="${4//[$'\t\r\n']}"
 
     local distro_specific_osname
-    distro_specific_osname=$(get_distro_specific_os_name) || return 1
+    distro_specific_osname="$(get_legacy_os_name)" || return 1
 
     local legacy_download_link=null
-    if [ "$shared_runtime" = true ]; then
+    if [[ "$runtime" == "dotnet" ]]; then
         legacy_download_link="$azure_feed/Runtime/$specific_version/dotnet-$distro_specific_osname-$normalized_architecture.$specific_version.tar.gz"
-    else
+    elif [ -z "$runtime" ]; then
         legacy_download_link="$azure_feed/Sdk/$specific_version/dotnet-dev-$distro_specific_osname-$normalized_architecture.$specific_version.tar.gz"
+    else
+        return 1
     fi
 
     echo "$legacy_download_link"
@@ -450,7 +534,7 @@ get_user_install_path() {
     eval $invocation
 
     if [ ! -z "${DOTNET_INSTALL_DIR:-}" ]; then
-        echo $DOTNET_INSTALL_DIR
+        echo "$DOTNET_INSTALL_DIR"
     else
         echo "$HOME/.dotnet"
     fi
@@ -464,7 +548,7 @@ resolve_installation_path() {
 
     local install_dir=$1
     if [ "$install_dir" = "<auto>" ]; then
-        local user_install_path=$(get_user_install_path)
+        local user_install_path="$(get_user_install_path)"
         say_verbose "resolve_installation_path: user_install_path=$user_install_path"
         echo "$user_install_path"
         return 0
@@ -479,11 +563,11 @@ resolve_installation_path() {
 get_installed_version_info() {
     eval $invocation
 
-    local install_root=$1
-    local version_file=$(combine_paths "$install_root" "$local_version_file_relative_path")
+    local install_root="$1"
+    local version_file="$(combine_paths "$install_root" "$local_version_file_relative_path")"
     say_verbose "Local version file: $version_file"
     if [ ! -z "$version_file" ] | [ -r "$version_file" ]; then
-        local version_info="$(cat $version_file)"
+        local version_info="$(cat "$version_file")"
         echo "$version_info"
         return 0
     fi
@@ -498,7 +582,7 @@ get_absolute_path() {
     eval $invocation
 
     local relative_or_absolute_path=$1
-    echo $(cd $(dirname "$1") && pwd -P)/$(basename "$1")
+    echo "$(cd "$(dirname "$1")" && pwd -P)/$(basename "$1")"
     return 0
 }
 
@@ -510,17 +594,25 @@ get_absolute_path() {
 copy_files_or_dirs_from_list() {
     eval $invocation
 
-    local root_path=$(remove_trailing_slash $1)
-    local out_path=$(remove_trailing_slash $2)
-    local override=$3
-    local override_switch=$(if [ "$override" = false ]; then printf -- "-n"; fi)
+    local root_path="$(remove_trailing_slash "$1")"
+    local out_path="$(remove_trailing_slash "$2")"
+    local override="$3"
+    local osname="$(get_current_os_name)"
+    local override_switch=$(
+        if [ "$override" = false ]; then
+            if [[ "$osname" == "linux-musl" ]]; then
+                printf -- "-u";
+            else
+                printf -- "-n";
+            fi
+        fi)
 
     cat | uniq | while read -r file_path; do
-        local path=$(remove_beginning_slash ${file_path#$root_path})
-        local target=$out_path/$path
+        local path="$(remove_beginning_slash "${file_path#$root_path}")"
+        local target="$out_path/$path"
         if [ "$override" = true ] || (! ([ -d "$target" ] || [ -e "$target" ])); then
-            mkdir -p $out_path/$(dirname $path)
-            cp -R $override_switch $root_path/$path $target
+            mkdir -p "$out_path/$(dirname "$path")"
+            cp -R $override_switch "$root_path/$path" "$target"
         fi
     done
 }
@@ -531,19 +623,19 @@ copy_files_or_dirs_from_list() {
 extract_dotnet_package() {
     eval $invocation
 
-    local zip_path=$1
-    local out_path=$2
+    local zip_path="$1"
+    local out_path="$2"
 
-    local temp_out_path=$(mktemp -d $temporary_file_template)
+    local temp_out_path="$(mktemp -d "$temporary_file_template")"
 
     local failed=false
     tar -xzf "$zip_path" -C "$temp_out_path" > /dev/null || failed=true
 
     local folders_with_version_regex='^.*/[0-9]+\.[0-9]+[^/]+/'
-    find $temp_out_path -type f | grep -Eo $folders_with_version_regex | copy_files_or_dirs_from_list $temp_out_path $out_path false
-    find $temp_out_path -type f | grep -Ev $folders_with_version_regex | copy_files_or_dirs_from_list $temp_out_path $out_path true
+    find "$temp_out_path" -type f | grep -Eo "$folders_with_version_regex" | sort | copy_files_or_dirs_from_list "$temp_out_path" "$out_path" false
+    find "$temp_out_path" -type f | grep -Ev "$folders_with_version_regex" | copy_files_or_dirs_from_list "$temp_out_path" "$out_path" "$override_non_versioned_files"
 
-    rm -rf $temp_out_path
+    rm -rf "$temp_out_path"
 
     if [ "$failed" = true ]; then
         say_err "Extraction failed"
@@ -557,14 +649,19 @@ extract_dotnet_package() {
 download() {
     eval $invocation
 
-    local remote_path=$1
-    local out_path=${2:-}
+    local remote_path="$1"
+    local out_path="${2:-}"
+
+    if [[ "$remote_path" != "http"* ]]; then
+        cp "$remote_path" "$out_path"
+        return $?
+    fi
 
     local failed=false
     if machine_has "curl"; then
-        downloadcurl $remote_path $out_path || failed=true
+        downloadcurl "$remote_path" "$out_path" || failed=true
     elif machine_has "wget"; then
-        downloadwget $remote_path $out_path || failed=true
+        downloadwget "$remote_path" "$out_path" || failed=true
     else
         failed=true
     fi
@@ -577,14 +674,17 @@ download() {
 
 downloadcurl() {
     eval $invocation
-    local remote_path=$1
-    local out_path=${2:-}
+    local remote_path="$1"
+    local out_path="${2:-}"
+
+    # Append feed_credential as late as possible before calling curl to avoid logging feed_credential
+    remote_path="${remote_path}${feed_credential}"
 
     local failed=false
     if [ -z "$out_path" ]; then
-        curl --retry 10 -sSL -f --create-dirs $remote_path || failed=true
+        curl --retry 10 -sSL -f --create-dirs "$remote_path" || failed=true
     else
-        curl --retry 10 -sSL -f --create-dirs -o $out_path $remote_path || failed=true
+        curl --retry 10 -sSL -f --create-dirs -o "$out_path" "$remote_path" || failed=true
     fi
     if [ "$failed" = true ]; then
         say_verbose "Curl download failed"
@@ -595,14 +695,17 @@ downloadcurl() {
 
 downloadwget() {
     eval $invocation
-    local remote_path=$1
-    local out_path=${2:-}
+    local remote_path="$1"
+    local out_path="${2:-}"
+
+    # Append feed_credential as late as possible before calling wget to avoid logging feed_credential
+    remote_path="${remote_path}${feed_credential}"
 
     local failed=false
     if [ -z "$out_path" ]; then
-        wget -q --tries 10 $remote_path || failed=true
+        wget -q --tries 10 -O - "$remote_path" || failed=true
     else
-        wget -v --tries 10 -O $out_path $remote_path || failed=true
+        wget --tries 10 -O "$out_path" "$remote_path" || failed=true
     fi
     if [ "$failed" = true ]; then
         say_verbose "Wget download failed"
@@ -615,63 +718,105 @@ calculate_vars() {
     eval $invocation
     valid_legacy_download_link=true
 
-    normalized_architecture=$(get_normalized_architecture_from_architecture "$architecture")
+    normalized_architecture="$(get_normalized_architecture_from_architecture "$architecture")"
     say_verbose "normalized_architecture=$normalized_architecture"
 
-    specific_version=$(get_specific_version_from_version $azure_feed $channel $normalized_architecture $version)
+    specific_version="$(get_specific_version_from_version "$azure_feed" "$channel" "$normalized_architecture" "$version")"
     say_verbose "specific_version=$specific_version"
     if [ -z "$specific_version" ]; then
-        say_err "Could not get version information."
+        say_err "Could not resolve version information."
         return 1
     fi
 
-    download_link=$(construct_download_link $azure_feed $channel $normalized_architecture $specific_version)
-    say_verbose "download_link=$download_link"
+    download_link="$(construct_download_link "$azure_feed" "$channel" "$normalized_architecture" "$specific_version")"
+    say_verbose "Constructed primary named payload URL: $download_link"
 
-    legacy_download_link=$(construct_legacy_download_link $azure_feed $channel $normalized_architecture $specific_version) || valid_legacy_download_link=false
+    legacy_download_link="$(construct_legacy_download_link "$azure_feed" "$channel" "$normalized_architecture" "$specific_version")" || valid_legacy_download_link=false
 
     if [ "$valid_legacy_download_link" = true ]; then
-        say_verbose "legacy_download_link=$legacy_download_link"
+        say_verbose "Constructed legacy named payload URL: $legacy_download_link"
     else
         say_verbose "Cound not construct a legacy_download_link; omitting..."
     fi
 
-    install_root=$(resolve_installation_path $install_dir)
-    say_verbose "install_root=$install_root"
+    install_root="$(resolve_installation_path "$install_dir")"
+    say_verbose "InstallRoot: $install_root"
 }
 
 install_dotnet() {
     eval $invocation
     local download_failed=false
+    local asset_name=''
+    local asset_relative_path=''
 
-    if is_dotnet_package_installed $install_root "sdk" $specific_version; then
-        say ".NET SDK version $specific_version is already installed."
+    if [[ "$runtime" == "dotnet" ]]; then
+        asset_relative_path="shared/Microsoft.NETCore.App"
+        asset_name=".NET Core Runtime"
+    elif [[ "$runtime" == "aspnetcore" ]]; then
+        asset_relative_path="shared/Microsoft.AspNetCore.App"
+        asset_name="ASP.NET Core Runtime"
+    elif [ -z "$runtime" ]; then
+        asset_relative_path="sdk"
+        asset_name=".NET Core SDK"
+    else
+        say_err "Invalid value for \$runtime"
+        return 1
+    fi
+
+    #  Check if the SDK version is already installed.
+    if is_dotnet_package_installed "$install_root" "$asset_relative_path" "$specific_version"; then
+        say "$asset_name version $specific_version is already installed."
         return 0
     fi
 
-    mkdir -p $install_root
-    zip_path=$(mktemp $temporary_file_template)
+    mkdir -p "$install_root"
+    zip_path="$(mktemp "$temporary_file_template")"
     say_verbose "Zip path: $zip_path"
 
     say "Downloading link: $download_link"
-    download "$download_link" $zip_path || download_failed=true
+
+    # Failures are normal in the non-legacy case for ultimately legacy downloads.
+    # Do not output to stderr, since output to stderr is considered an error.
+    download "$download_link" "$zip_path" 2>&1 || download_failed=true
 
     #  if the download fails, download the legacy_download_link
-    if [ "$download_failed" = true ] && [ "$valid_legacy_download_link" = true ]; then
+    if [ "$download_failed" = true ]; then
         say "Cannot download: $download_link"
-        download_link=$legacy_download_link
-        zip_path=$(mktemp $temporary_file_template)
-        say_verbose "Legacy zip path: $zip_path"
-        say "Downloading legacy link: $download_link"
-        download "$download_link" $zip_path
+
+        if [ "$valid_legacy_download_link" = true ]; then
+            download_failed=false
+            download_link="$legacy_download_link"
+            zip_path="$(mktemp "$temporary_file_template")"
+            say_verbose "Legacy zip path: $zip_path"
+            say "Downloading legacy link: $download_link"
+            download "$download_link" "$zip_path" 2>&1 || download_failed=true
+
+            if [ "$download_failed" = true ]; then
+                say "Cannot download: $download_link"
+            fi
+        fi
+    fi
+
+    if [ "$download_failed" = true ]; then
+        say_err "Could not find/download: \`$asset_name\` with version = $specific_version"
+        say_err "Refer to: https://aka.ms/dotnet-os-lifecycle for information on .NET Core support"
+        return 1
     fi
 
     say "Extracting zip from $download_link"
-    extract_dotnet_package $zip_path $install_root
+    extract_dotnet_package "$zip_path" "$install_root"
+
+    #  Check if the SDK version is now installed; if not, fail the installation.
+    if ! is_dotnet_package_installed "$install_root" "$asset_relative_path" "$specific_version"; then
+        say_err "\`$asset_name\` with version = $specific_version failed to install with an unknown error."
+        return 1
+    fi
 
     return 0
 }
 
+args=("$@")
+
 local_version_file_relative_path="/.version"
 bin_folder_relative_path=""
 temporary_file_template="${TMPDIR:-/tmp}/dotnet.XXXXXXXXX"
@@ -682,19 +827,23 @@ install_dir="<auto>"
 architecture="<auto>"
 dry_run=false
 no_path=false
+no_cdn=false
 azure_feed="https://dotnetcli.azureedge.net/dotnet"
 uncached_feed="https://dotnetcli.blob.core.windows.net/dotnet"
+feed_credential=""
 verbose=false
-shared_runtime=false
+runtime=""
 runtime_id=""
+override_non_versioned_files=true
+non_dynamic_parameters=""
 
 while [ $# -ne 0 ]
 do
-    name=$1
-    case $name in
+    name="$1"
+    case "$name" in
         -c|--channel|-[Cc]hannel)
             shift
-            channel=$1
+            channel="$1"
             ;;
         -v|--version|-[Vv]ersion)
             shift
@@ -709,31 +858,60 @@ do
             architecture="$1"
             ;;
         --shared-runtime|-[Ss]hared[Rr]untime)
-            shared_runtime=true
+            say_warning "The --shared-runtime flag is obsolete and may be removed in a future version of this script. The recommended usage is to specify '--runtime dotnet'."
+            if [ -z "$runtime" ]; then
+                runtime="dotnet"
+            fi
+            ;;
+        --runtime|-[Rr]untime)
+            shift
+            runtime="$1"
+            if [[ "$runtime" != "dotnet" ]] && [[ "$runtime" != "aspnetcore" ]]; then
+                say_err "Unsupported value for --runtime: '$1'. Valid values are 'dotnet' and 'aspnetcore'."
+                exit 1
+            fi
             ;;
         --dry-run|-[Dd]ry[Rr]un)
             dry_run=true
             ;;
         --no-path|-[Nn]o[Pp]ath)
             no_path=true
+            non_dynamic_parameters+=" $name"
             ;;
         --verbose|-[Vv]erbose)
             verbose=true
+            non_dynamic_parameters+=" $name"
+            ;;
+        --no-cdn|-[Nn]o[Cc]dn)
+            no_cdn=true
+            non_dynamic_parameters+=" $name"
             ;;
         --azure-feed|-[Aa]zure[Ff]eed)
             shift
             azure_feed="$1"
+            non_dynamic_parameters+=" $name "\""$1"\"""
             ;;
         --uncached-feed|-[Uu]ncached[Ff]eed)
             shift
             uncached_feed="$1"
+            non_dynamic_parameters+=" $name "\""$1"\"""
+            ;;
+        --feed-credential|-[Ff]eed[Cc]redential)
+            shift
+            feed_credential="$1"
+            non_dynamic_parameters+=" $name "\""$1"\"""
             ;;
         --runtime-id|-[Rr]untime[Ii]d)
             shift
             runtime_id="$1"
+            non_dynamic_parameters+=" $name "\""$1"\"""
+            ;;
+        --skip-non-versioned-files|-[Ss]kip[Nn]on[Vv]ersioned[Ff]iles)
+            override_non_versioned_files=false
+            non_dynamic_parameters+=" $name"
             ;;
         -?|--?|-h|--help|-[Hh]elp)
-            script_name="$(basename $0)"
+            script_name="$(basename "$0")"
             echo ".NET Tools Installer"
             echo "Usage: $script_name [-c|--channel <CHANNEL>] [-v|--version <VERSION>] [-p|--prefix <DESTINATION>]"
             echo "       $script_name -h|-?|--help"
@@ -741,7 +919,7 @@ do
             echo "$script_name is a simple command line interface for obtaining dotnet cli."
             echo ""
             echo "Options:"
-            echo "  -c,--channel <CHANNEL>         Download from the CHANNEL specified, Defaults to \`$channel\`."
+            echo "  -c,--channel <CHANNEL>         Download from the channel specified, Defaults to \`$channel\`."
             echo "      -Channel"
             echo "          Possible values:"
             echo "          - Current - most current release"
@@ -750,6 +928,7 @@ do
             echo "              examples: 2.0; 1.0"
             echo "          - Branch name"
             echo "              examples: release/2.0.0; Master"
+            echo "          Note: The version parameter overrides the channel parameter."
             echo "  -v,--version <VERSION>         Use specific VERSION, Defaults to \`$version\`."
             echo "      -Version"
             echo "          Possible values:"
@@ -758,20 +937,32 @@ do
             echo "              coherent applies only to SDK downloads"
             echo "          - 3-part version in a format A.B.C - represents specific version of build"
             echo "              examples: 2.0.0-preview2-006120; 1.1.0"
-            echo "  -i,--install-dir <DIR>         Install under specified location (see Install Location below)"
+            echo "  -i,--install-dir <DIR>             Install under specified location (see Install Location below)"
             echo "      -InstallDir"
-            echo "  --architecture <ARCHITECTURE>  Architecture of .NET Tools. Currently only x64 is supported."
+            echo "  --architecture <ARCHITECTURE>      Architecture of dotnet binaries to be installed, Defaults to \`$architecture\`."
             echo "      --arch,-Architecture,-Arch"
-            echo "  --shared-runtime               Installs just the shared runtime bits, not the entire SDK."
-            echo "      -SharedRuntime"
-            echo "  --dry-run,-DryRun              Do not perform installation. Display download link."
-            echo "  --no-path, -NoPath             Do not set PATH for the current process."
-            echo "  --verbose,-Verbose             Display diagnostics information."
-            echo "  --azure-feed,-AzureFeed        Azure feed location. Defaults to $azure_feed, This parameter typically is not changed by the user."
-            echo "  --uncached-feed,-UncachedFeed  Uncached feed location. This parameter typically is not changed by the user."
-            echo "  --runtime-id                   Installs the .NET Tools for the given platform (use linux-x64 for portable linux)."
+            echo "          Possible values: x64, arm, and arm64"
+            echo "  --runtime <RUNTIME>                Installs a shared runtime only, without the SDK."
+            echo "      -Runtime"
+            echo "          Possible values:"
+            echo "          - dotnet     - the Microsoft.NETCore.App shared runtime"
+            echo "          - aspnetcore - the Microsoft.AspNetCore.App shared runtime"
+            echo "  --skip-non-versioned-files         Skips non-versioned files if they already exist, such as the dotnet executable."
+            echo "      -SkipNonVersionedFiles"
+            echo "  --dry-run,-DryRun                  Do not perform installation. Display download link."
+            echo "  --no-path, -NoPath                 Do not set PATH for the current process."
+            echo "  --verbose,-Verbose                 Display diagnostics information."
+            echo "  --azure-feed,-AzureFeed            Azure feed location. Defaults to $azure_feed, This parameter typically is not changed by the user."
+            echo "  --uncached-feed,-UncachedFeed      Uncached feed location. This parameter typically is not changed by the user."
+            echo "  --no-cdn,-NoCdn                    Disable downloading from the Azure CDN, and use the uncached feed directly."
+            echo "  --feed-credential,-FeedCredential  Azure feed shared access token. This parameter typically is not specified."
+            echo "  --runtime-id                       Installs the .NET Tools for the given platform (use linux-x64 for portable linux)."
             echo "      -RuntimeId"
-            echo "  -?,--?,-h,--help,-Help         Shows this help message"
+            echo "  -?,--?,-h,--help,-Help             Shows this help message"
+            echo ""
+            echo "Obsolete parameters:"
+            echo "  --shared-runtime                   The recommended alternative is '--runtime dotnet'."
+            echo "      -SharedRuntime                 Installs just the shared runtime bits, not the entire SDK."
             echo ""
             echo "Install Location:"
             echo "  Location is chosen in following order:"
@@ -789,27 +980,40 @@ do
     shift
 done
 
+if [ "$no_cdn" = true ]; then
+    azure_feed="$uncached_feed"
+fi
+
 check_min_reqs
 calculate_vars
+script_name=$(basename "$0")
 
 if [ "$dry_run" = true ]; then
-    say "Payload URL: $download_link"
+    say "Payload URLs:"
+    say "Primary named payload URL: $download_link"
     if [ "$valid_legacy_download_link" = true ]; then
-        say "Legacy payload URL: $legacy_download_link"
+        say "Legacy named payload URL: $legacy_download_link"
     fi
-    say "Repeatable invocation: ./$(basename $0) --version $specific_version --channel $channel --install-dir $install_dir"
+    repeatable_command="./$script_name --version "\""$specific_version"\"" --install-dir "\""$install_root"\"" --architecture "\""$normalized_architecture"\"""
+    if [[ "$runtime" == "dotnet" ]]; then
+        repeatable_command+=" --runtime "\""dotnet"\"""
+    elif [[ "$runtime" == "aspnetcore" ]]; then
+        repeatable_command+=" --runtime "\""aspnetcore"\"""
+    fi
+    repeatable_command+="$non_dynamic_parameters"
+    say "Repeatable invocation: $repeatable_command"
     exit 0
 fi
 
 check_pre_reqs
 install_dotnet
 
-bin_path=$(get_absolute_path $(combine_paths $install_root $bin_folder_relative_path))
+bin_path="$(get_absolute_path "$(combine_paths "$install_root" "$bin_folder_relative_path")")"
 if [ "$no_path" = false ]; then
     say "Adding to current process PATH: \`$bin_path\`. Note: This change will be visible only when sourcing script."
-    export PATH=$bin_path:$PATH
+    export PATH="$bin_path":"$PATH"
 else
     say "Binaries of dotnet can be found in $bin_path"
 fi
 
-say "Installation finished successfully."
\ No newline at end of file
+say "Installation finished successfully."
diff --git a/src/installer.ts b/src/installer.ts
index f90dc37..0ae3cf9 100644
--- a/src/installer.ts
+++ b/src/installer.ts
@@ -5,7 +5,6 @@ import * as exec from '@actions/exec';
 import * as io from '@actions/io';
 import * as tc from '@actions/tool-cache';
 import httpClient = require('typed-rest-client/HttpClient');
-import httpInterfaces = require('typed-rest-client/Interfaces');
 import {HttpClientResponse} from 'typed-rest-client/HttpClient';
 import {chmodSync} from 'fs';
 import * as os from 'os';
@@ -61,26 +60,6 @@ export class DotnetCoreInstaller {
 
     // Prepend the tools path. instructs the agent to prepend for future tasks
     core.addPath(toolPath);
-
-    try {
-      let globalToolPath: string = '';
-      if (IS_WINDOWS) {
-        globalToolPath = path.join(
-          process.env.USERPROFILE || '',
-          '.dotnet\\tools'
-        );
-      } else {
-        globalToolPath = path.join(process.env.HOME || '', '.dotnet/tools');
-      }
-
-      await io.mkdirP(globalToolPath);
-      core.addPath(globalToolPath);
-    } catch (error) {
-      //nop
-    }
-
-    // Set DOTNET_ROOT for dotnet core Apphost to find runtime since it is installed to a non well-known location.
-    core.exportVariable('DOTNET_ROOT', toolPath);
   }
 
   private getLocalTool(): string {
@@ -140,7 +119,7 @@ export class DotnetCoreInstaller {
     }
 
     if (resultCode != 0) {
-      throw `Failed to detect os with result code ${resultCode}`;
+      throw `Failed to detect os with result code ${resultCode}. Output: ${output}`;
     }
 
     let index;
@@ -205,6 +184,7 @@ export class DotnetCoreInstaller {
   ): Promise<string[]> {
     let downloadUrls = [];
     let releasesJSON = await this.getReleasesJson();
+    core.debug('Releases: ' + releasesJSON);
 
     let releasesInfo = JSON.parse(await releasesJSON.readBody());
     releasesInfo = releasesInfo.filter((releaseInfo: any) => {
@@ -320,7 +300,7 @@ export class DotnetCoreInstaller {
     }
 
     if (resultCode != 0) {
-      throw `Failed to get download urls with result code ${resultCode}`;
+      throw `Failed to get download urls with result code ${resultCode}. ${output}`;
     }
 
     let primaryUrl: string = '';