PowerShell script to download latest stable Cilium CLI for Windows and install it.

Install-Cilium-CLI.ps1

# PowerShell version of Cilium CLI installation.
# *nix version here: https://github.com/cilium/cilium-cli

# Converted using Copilot, validated by a human :D

# Requires Administrative privileges to run end-to-end

$ErrorActionPreference = "Stop"

# Get latest stable Cilium CLI version
$CILIUM_CLI_VERSION = (Invoke-RestMethod -Uri "https://raw.githubusercontent.com/cilium/cilium-cli/main/stable.txt").Trim()

# Set OS/arch for Windows release asset naming
$GOOS = "windows"
switch ($env:PROCESSOR_ARCHITECTURE.ToUpper()) {
    "AMD64" { $GOARCH = "amd64" }
    "ARM64" { $GOARCH = "arm64" }
    default { throw "Unsupported architecture: $env:PROCESSOR_ARCHITECTURE" }
}

$archive = "cilium-windows-$GOARCH.zip"
$checksum = "$archive.sha256sum"
$baseUrl = "https://github.com/cilium/cilium-cli/releases/download/$CILIUM_CLI_VERSION"

# Download archive + checksum
Invoke-WebRequest -Uri "$baseUrl/$archive" -OutFile $archive
Invoke-WebRequest -Uri "$baseUrl/$checksum" -OutFile $checksum

# Verify SHA256
$expected = (Get-Content $checksum | Select-Object -First 1).Split(" ", [System.StringSplitOptions]::RemoveEmptyEntries)[0].ToLower()
$actual = (Get-FileHash -Path $archive -Algorithm SHA256).Hash.ToLower()
if ($actual -ne $expected) {
    throw "SHA256 mismatch for $archive. Expected $expected, got $actual"
}

# Install location (admin required for Program Files)
$installDir = "$env:ProgramFiles\cilium"
New-Item -ItemType Directory -Path $installDir -Force | Out-Null

# Extract .zip and install cilium.exe
$tempDir = Join-Path $env:TEMP "cilium-extract-$([guid]::NewGuid().ToString('N'))"
New-Item -ItemType Directory -Path $tempDir -Force | Out-Null

Expand-Archive -Path $archive -DestinationPath $tempDir -Force

$ciliumExe = Join-Path $tempDir "cilium.exe"
if (-not (Test-Path $ciliumExe)) {
    throw "cilium.exe not found in extracted archive."
}

Move-Item -Path $ciliumExe -Destination (Join-Path $installDir "cilium.exe") -Force
Remove-Item -Path $tempDir -Recurse -Force

# Optional: add to user PATH if not already there
if (($env:Path -split ';') -notcontains $installDir) {
    [Environment]::SetEnvironmentVariable(
        "Path",
        [Environment]::GetEnvironmentVariable("Path", "User") + ";$installDir",
        "User"
    )
    Write-Host "Added $installDir to your user PATH. Restart terminal to pick it up."
}

# Cleanup
Remove-Item $archive, $checksum -Force

Write-Host "Installed Cilium CLI to $installDir"
Write-Host "Run: cilium version"