Exporting Oracle OCI Compute Instances to CSV

Host,Os
fqdn-or-ip,windows|linux|unknown

<#
.SYNOPSIS
  Export Oracle OCI compute instances to a DMC-ready CSV (Host,Os) with module preflight checks.

  REQUIREMENTS:
  - PowerShell 5.1+ (PowerShell 7+ recommended)
  - OCI account with compute instance enumeration permissions
  - Compartment access to target resources
  - API key configured with proper permissions
  - Internet access for automatic module installation
  - Write access to output directory for CSV export

.DESCRIPTION
  - Ensures required OCI PowerShell modules are present.
  - Connects to OCI using configured credentials.
  - Enumerates compute instances from specified compartments.
  - Exports Host (FQDN or IP) and Os (windows|linux|unknown) as DMC expects.
  - Focuses on private IP addresses for internal network scanning.

.PARAMETER CompartmentId
  OCI Compartment OCID to enumerate compute instances from.

.PARAMETER OutputPath
  Path to save CSV file. Defaults to .\oci_compute_instances.csv

.PARAMETER DefaultOS
  Optional override for OS column. Accepts 'Windows' or 'Linux'. Defaults to 'unknown'.

.PARAMETER UsePublicIPs
  Switch: use public IPs instead of private IPs (default is private IPs).

.EXAMPLE
  .\Export-OCIComputeInstances.ps1 -CompartmentId "ocid1.compartment.oc1..example" -DefaultOS Linux
#>

[CmdletBinding()]
param(
  [Parameter(Mandatory)] [string] $CompartmentId,
  [Parameter()]          [string] $OutputPath = ".\oci_compute_instances.csv",
  [Parameter()] [ValidateSet('Windows','Linux')] [string] $DefaultOS,
  [Parameter()] [switch] $UsePublicIPs
)

# -----------------------------
# Preflight: Environment checks
# -----------------------------
# Enforce TLS 1.2 for gallery downloads (older hosts)
try { [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12 } catch {}

function Write-Info { param([string]$m) Write-Host "[INFO]  $m" -ForegroundColor Cyan }
function Write-Warn { param([string]$m) Write-Host "[WARN]  $m" -ForegroundColor Yellow }
function Write-Err  { param([string]$m) Write-Host "[ERROR] $m" -ForegroundColor Red }

# Minimal PS version (5.1+ or PowerShell 7+ recommended)
$psVerOk = ($PSVersionTable.PSVersion.Major -ge 5)
if (-not $psVerOk) {
  Write-Err "PowerShell 5.1 or later required. Current: $($PSVersionTable.PSVersion)"
  exit 1
}

# Ensure NuGet provider (for Install-Module), ignore errors on locked-down hosts
try {
  if (-not (Get-PackageProvider -ListAvailable | Where-Object { $_.Name -eq 'NuGet' })) {
    Write-Info "Installing NuGet package provider..."
    Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force -Scope CurrentUser | Out-Null
  }
} catch { Write-Warn "Could not ensure NuGet provider (offline/locked-down?). If module install fails, install OCI.PSModules manually." }

# Helper to ensure a module is available; installs to CurrentUser if missing.
function Ensure-Module {
  param(
    [Parameter(Mandatory)] [string] $Name,
    [string] $MinVersion = "0.0.0"
  )
  $loaded = Get-Module -ListAvailable -Name $Name | Sort-Object Version -Descending | Select-Object -First 1
  if ($loaded -and ($loaded.Version -ge [version]$MinVersion)) {
    Write-Info "Module '$Name' found (v$($loaded.Version))."
    return $true
  }

  Write-Info "Module '$Name' not found. Attempting install from PSGallery (CurrentUser)..."
  try {
    # Avoid prompts on first-time PSGallery use
    if (-not (Get-PSRepository -Name 'PSGallery' -ErrorAction SilentlyContinue)) {
      Register-PSRepository -Default -ErrorAction SilentlyContinue
    }
    Set-PSRepository -Name 'PSGallery' -InstallationPolicy Trusted -ErrorAction SilentlyContinue
    Install-Module -Name $Name -Scope CurrentUser -Force -AllowClobber -ErrorAction Stop
    Write-Info "Module '$Name' installed."
    return $true
  } catch {
    Write-Warn "Failed to install '$Name' from PSGallery: $($_.Exception.Message)"
    return $false
  }
}

# -----------------------------
# Required modules
# -----------------------------
Write-Info "Ensuring required OCI PowerShell modules are available..."

$okOCI = Ensure-Module -Name "OCI.PSModules"
if (-not $okOCI) {
  Write-Err @"
OCI.PSModules is required but could not be installed automatically.
Options:
  1) Install from PowerShell Gallery (if internet is allowed):
       Install-Module OCI.PSModules -Scope CurrentUser
  2) Install individual modules:
       Install-Module OCI.PSModules.Common -Scope CurrentUser
       Install-Module OCI.PSModules.Compute -Scope CurrentUser
       Install-Module OCI.PSModules.Network -Scope CurrentUser
"@
  exit 1
}

# Import required modules
try {
  Import-Module OCI.PSModules.Common -ErrorAction Stop
  Import-Module OCI.PSModules.Compute -ErrorAction Stop
  Import-Module OCI.PSModules.Network -ErrorAction Stop
  Write-Info "OCI modules imported successfully."
} catch {
  Write-Err "Failed to import OCI modules: $($_.Exception.Message)"
  exit 1
}

# -----------------------------
# Check OCI Configuration
# -----------------------------
Write-Info "Checking OCI client configuration..."

try {
  $config = Get-OCIClientConfig -ErrorAction Stop
  if (-not $config) {
    Write-Err @"
OCI client configuration not found. Please configure your OCI environment first:

1. Run: Set-OCIClientConfig
2. Enter your Tenancy OCID, User OCID, Region, and API key details
3. Or manually create ~/.oci/config file

For more information, see: https://docs.oracle.com/en-us/iaas/tools/powershell-sdk/using/getting-started.html
"@
    exit 1
  }
  Write-Info "OCI configuration found and validated."
} catch {
  Write-Err "Failed to validate OCI configuration: $($_.Exception.Message)"
  Write-Err "Please run Set-OCIClientConfig to configure your OCI environment."
  exit 1
}

# -----------------------------
# Normalize Default OS
# -----------------------------
$defaultOsCsv = if ($PSBoundParameters.ContainsKey('DefaultOS')) {
  if ($DefaultOS -eq 'Windows') { 'windows' } else { 'linux' }
} else { 'unknown' }

Write-Info "Default Os value for CSV rows: '$defaultOsCsv'"
Write-Info "IP preference: $($UsePublicIPs ? 'Public IPs' : 'Private IPs')"

# -----------------------------
# Collect Compute Instances -> DMC CSV rows
# -----------------------------
Write-Info "Enumerating compute instances from compartment: $CompartmentId"

try {
  $instances = Get-OCIComputeInstance -CompartmentId $CompartmentId -ErrorAction Stop
  Write-Info "Found $($instances.Count) compute instances."
} catch {
  Write-Err "Failed to enumerate compute instances: $($_.Exception.Message)"
  exit 1
}

if ($instances.Count -eq 0) {
  Write-Warn "No compute instances found in the specified compartment."
}

$rows = @()
foreach ($instance in $instances) {
  Write-Info "Processing instance: $($instance.DisplayName) (State: $($instance.LifecycleState))"

  # Skip instances that are not running
  if ($instance.LifecycleState -ne "RUNNING") {
    Write-Warn "Skipping instance '$($instance.DisplayName)' - not running (State: $($instance.LifecycleState))"
    continue
  }

  try {
    # Get network interfaces for this instance
    $vnics = Get-OCINetworkVnic -CompartmentId $CompartmentId -InstanceId $instance.Id -ErrorAction Stop

    foreach ($vnic in $vnics) {
      $ipAddress = $null

      if ($UsePublicIPs -and $vnic.PublicIp) {
        $ipAddress = $vnic.PublicIp
        Write-Info "  Using public IP: $ipAddress"
      } elseif ($vnic.PrivateIp) {
        $ipAddress = $vnic.PrivateIp
        Write-Info "  Using private IP: $ipAddress"
      }

      if ($ipAddress) {
        # Try to resolve FQDN; fall back to IP
        $fqdn = $null
        try { 
          $fqdn = [System.Net.Dns]::GetHostEntry($ipAddress).HostName 
          if ($fqdn -and $fqdn -ne $ipAddress) {
            Write-Info "  Resolved FQDN: $fqdn"
          }
        } catch {}

        $rows += [pscustomobject]@{
          Host = if ($fqdn -and $fqdn -ne $ipAddress) { $fqdn } else { $ipAddress }
          Os   = $defaultOsCsv
        }
      }
    }
  } catch {
    Write-Warn "Failed to get network interfaces for instance '$($instance.DisplayName)': $($_.Exception.Message)"
  }
}

if ($rows.Count -eq 0) {
  Write-Warn "No IP addresses discovered from compute instances. Check compartment permissions and network configuration."
}

# -----------------------------
# Write CSV
# -----------------------------
try {
  $rows | Select-Object Host, Os | Export-Csv -Path $OutputPath -NoTypeInformation -Encoding UTF8
  Write-Info "Export complete: $OutputPath"
  Write-Info "Columns: Host,Os"
  Write-Info "Total rows exported: $($rows.Count)"
} catch {
  Write-Err "Failed to write CSV to '$OutputPath': $($_.Exception.Message)"
  exit 1
}

# -----------------------------
# Summary
# -----------------------------
Write-Host ""
Write-Info "Export Summary:"
Write-Info "  Compartment ID: $CompartmentId"
Write-Info "  Instances processed: $($instances.Count)"
Write-Info "  IP addresses exported: $($rows.Count)"
Write-Info "  Default OS assumption: $defaultOsCsv"
Write-Info "  IP preference: $($UsePublicIPs ? 'Public IPs' : 'Private IPs')"
Write-Host ""

.\Export-OCIComputeInstances.ps1 -CompartmentId "ocid1.compartment.oc1..example"

.\Export-OCIComputeInstances.ps1 -CompartmentId "ocid1.compartment.oc1..example" -DefaultOS Windows

.\Export-OCIComputeInstances.ps1 -CompartmentId "ocid1.compartment.oc1..example" -DefaultOS Linux

.\Export-OCIComputeInstances.ps1 -CompartmentId "ocid1.compartment.oc1..example" -OutputPath "C:\exports\oci_servers.csv"

.\Export-OCIComputeInstances.ps1 -CompartmentId "ocid1.compartment.oc1..example" -UsePublicIPs

Install-Module -Name OCI.PSModules -Scope CurrentUser

Install-Module -Name OCI.PSModules.Common -Scope CurrentUser
Install-Module -Name OCI.PSModules.Compute -Scope CurrentUser
Install-Module -Name OCI.PSModules.Network -Scope CurrentUser

Import-Module OCI.PSModules.Common
Set-OCIClientConfig

[DEFAULT]
user=ocid1.user.oc1..example
fingerprint=xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx
key_file=~/.oci/oci_api_key.pem
tenancy=ocid1.tenancy.oc1..example
region=us-ashburn-1

# Check PowerShell Gallery access
Get-PSRepository -Name 'PSGallery'

# Install manually with verbose output
Install-Module -Name OCI.PSModules -Scope CurrentUser -Verbose

# Check current configuration
Get-OCIClientConfig

# Reconfigure if needed
Set-OCIClientConfig