Merge pull request #5906 from kit-ty-kate/windows-installer

Provide an install.ps1 PowerShell script to install opam on Windows

Author: dra27

master_changes.md

@@ -73,6 +73,7 @@ users)
 ## Release scripts
 
 ## Install script
+  * Provide a shell/install.ps1 PowerShell script to install opam on Windows [#5906 @kit-ty-kate @dra27]
 
 ## Admin
 

shell/install.ps1

@@ -0,0 +1,120 @@
+<#
+  .SYNOPSIS
+  Downloads and installs opam from binaries distributed on GitHub.
+
+  .DESCRIPTION
+  Script is able to perform either a per-machine or per-user installation of
+  opam for any version of opam after 2.2.0~beta2. By default it will install the
+  latest released version.
+
+  .LINK
+  See https://opam.ocaml.org/doc/Install.html for further information.
+#>
+
+param (
+  # Install the latest alpha, beta or rc
+  [switch]$Dev,
+  # Install this specific version of opam instead of the latest
+  [string]$Version = "2.2.0~rc1",
+  # Specify the installation directory for the opam binary
+  [string]$OpamBinDir = $null
+)
+
+$DevVersion = "2.2.0~rc1"
+$IsAdmin = (New-Object Security.Principal.WindowsPrincipal([Security.Principal.WindowsIdentity]::GetCurrent())).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
+$DefaultBinDir = If ($IsAdmin) {"$Env:ProgramFiles\opam\bin"} Else {"$Env:LOCALAPPDATA\Programs\opam\bin"}
+
+$SHA512s = @{
+  "opam-2.2.0-beta2-x86_64-windows.exe" = "74f034ccc30ef0b2041283ff125be2eab565d4019e79f946b515046c4c290a698266003445f38b91321a9ef931093651f861360906ff06c076c24d18657e2aaf";
+  "opam-2.2.0-beta3-x86_64-windows.exe" = "f09337d94e06cedb379c5bf45a50a79cf2b2e529d7c2bb9b35c8a56d40902ff8c7e3f4de9c75fb5c8dd8272b87b2a2645b14e40ef965376ef0d19afd923acf3b";
+  "opam-2.2.0-rc1-x86_64-windows.exe" = "f2ec830a5706c45cb56a96713e296ef756c3f2904ca15f7c2ad0442916a9585fa1de8070208f2a6bb3a84dc74b677f946f5bc386c8ed1489da802b1d66a5e094";
+}
+
+Function DownloadAndCheck {
+  param (
+    [string]$OpamBinUrl,
+    [string]$OpamBinTmpLoc,
+    [string]$OpamBinName
+  )
+
+  if (-not $SHA512s.ContainsKey($OpamBinName)) {
+    throw "no sha"
+  }
+
+  [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
+  (New-Object System.Net.WebClient).DownloadFile($OpamBinUrl, $OpamBinTmpLoc)
+  $Hash = (Get-FileHash -Path $OpamBinTmpLoc -Algorithm SHA512).Hash
+
+  if ($Hash -ne "$($SHA512s[$OpamBinName])") {
+    throw "Checksum mismatch, a problem occurred during download."
+  }
+}
+
+if (-not [System.Environment]::Is64BitOperatingSystem) {
+  throw "opam requires a 64-bit version of Windows"
+}
+
+if ($Dev.IsPresent) {
+  $Version = $DevVersion
+}
+
+$Tag = $Version.Replace("~", "-")
+$Arch = "x86_64"
+$OS = "windows"
+$OpamBinUrlBase = "https://github.com/ocaml/opam/releases/download/"
+$OpamBinName = "opam-$Tag-$Arch-$OS.exe"
+$OpamBinUrl = "$OpamBinUrlBase$Tag/$OpamBinName"
+
+$OpamBinTmpLoc = "$Env:TEMP\$OpamBinName"
+
+if (-not (Test-Path -Path $OpamBinTmpLoc -IsValid)) {
+  throw "Failed to determine a temporary path for downloading opam"
+}
+
+Write-Host "## Downloading opam $Version for Windows on x86_64"
+$esc = [char]27
+
+if ([string]::IsNullOrEmpty($OpamBinDir)) {
+  $OpamBinDir = Read-Host "## Where should it be installed? [$esc[1m$DefaultBinDir$esc[0m]"
+  if ([string]::IsNullOrEmpty($OpamBinDir)) {
+    $OpamBinDir = $DefaultBinDir
+  }
+}
+
+if (-not (Test-Path -Path $OpamBinDir -IsValid) -or $OpamBinDir -contains ';') {
+  throw "Destination given for installation is not a valid path"
+}
+
+# Check existing opam binaries
+$AllOpam = Get-Command -All -Name opam -CommandType Application -ErrorAction Ignore | ForEach-Object -MemberName Source
+foreach($OneOpam in $AllOpam) {
+  if ($OneOpam -ne "$OpamBinDir\opam.exe") {
+    throw "We detected another opam binary installed at '$OneOpam'. To ensure problems won't occur later, please uninstall it or remove it from the PATH"
+  }
+}
+
+DownloadAndCheck -OpamBinUrl $OpamBinUrl -OpamBinTmpLoc $OpamBinTmpLoc -OpamBinName $OpamBinName
+
+# Install the binary
+if (-not (Test-Path -Path $OpamBinDir -PathType Container)) {
+  [void](New-Item -Force -Path $OpamBinDir -Type Directory)
+}
+[void](Move-Item -Force -Path $OpamBinTmpLoc -Destination "$OpamBinDir\opam.exe")
+
+# Add the newly installed binary to PATH for this and future sessions
+$EnvTarget = If ($IsAdmin) {'MACHINE'} Else {'USER'}
+foreach ($loc in $EnvTarget, 'PROCESS') {
+  $PATH = [Environment]::GetEnvironmentVariable('PATH', $loc)
+  if (-not ($PATH -split ';' -contains $OpamBinDir)) {
+    [Environment]::SetEnvironmentVariable('PATH', "$OpamBinDir;$PATH", $loc)
+    if ($loc -ne 'PROCESS') {
+      Write-Host "## opam has added $OpamBinDir to the $loc PATH for future sessions"
+      Write-Host ""
+      Write-Host "Please use the Environment Variables editor in Control Panel to remove"
+      Write-Host "this entry if you subsequently decide to remove opam from your system"
+      Write-Host "(it can be started by running $esc[1mrundll32 sysdm.cpl,EditEnvironmentVariables$esc[0m)"
+    }
+  }
+}
+
+Write-Host "## opam $Version installed to $OpamBinDir"