Uninstallable Key

Uninstallable Key Usage

The uninstallable key in Cimian catalogs allows you to control whether a package can be uninstalled. This feature is based on Munki's implementation and provides both explicit control and automatic determination of uninstallability.

Basic Usage

Explicit Control

You can explicitly set whether an item can be uninstalled:

# Example: Package that should never be uninstalled
name: "critical-system-component"
version: "1.0.0"
installer:
  type: "msi"
  location: "/packages/critical-component-1.0.0.msi"
  hash: "abc123..."
uninstallable: false  # Explicitly prevent uninstalling

# Example: Package that can always be uninstalled
name: "optional-tool"
version: "2.1.0"
installer:
  type: "exe"
  location: "/packages/optional-tool-2.1.0.exe"
  hash: "def456..."
uninstaller:
  location: "/packages/optional-tool-uninstaller.exe"
  arguments: ["/S"]
uninstallable: true   # Explicitly allow uninstalling

Automatic Determination

When the uninstallable key is omitted (or set to null), Cimian automatically determines if the item can be uninstalled based on these criteria:

Automatically Uninstallable Items

1. Items with explicit uninstallers:

name: "app-with-uninstaller"
version: "1.0.0"
installer:
  type: "exe"
  location: "/packages/app-1.0.0.exe"
uninstaller:
  location: "/packages/app-uninstaller.exe"
  arguments: ["/quiet"]
# uninstallable: auto-determined as true

2. MSI packages (built-in uninstall support):

name: "msi-application"
version: "3.2.1"
installer:
  type: "msi"
  location: "/packages/app-3.2.1.msi"
# uninstallable: auto-determined as true

3. Chocolatey packages:

name: "choco-package"
version: "1.5.0"
installer:
  type: "nupkg"
  location: "/packages/app.1.5.0.nupkg"
# uninstallable: auto-determined as true

4. MSIX / APPX packages:

name: "store-app"
version: "2.0.0"
installer:
  type: "msix"
  location: "/packages/store-app-2.0.0.msix"
installs:
  - type: msix
    identity_name: com.example.storeapp
    version: 2.0.0
uninstaller:
  - type: msix
    identity_name: com.example.storeapp
# uninstallable: auto-determined as true (via the installs entry's identity_name).
# cimiimport auto-emits both blocks when importing a .msix file.
# Install runs Add-AppxProvisionedPackage -Online; uninstall runs
# Remove-AppxProvisionedPackage -Online with the resolved PackageFullName
# that was persisted to HKLM\SOFTWARE\ManagedInstalls\<Name> at install time.
# Note: currently-signed-in users must log out/back in to see a newly provisioned app.

5. Items with registry checks:

name: "registry-tracked-app"
version: "1.1.0"
installer:
  type: "exe"
  location: "/packages/app-1.1.0.exe"
check:
  registry:
    name: "MyApplication"
    version: "1.1.0"
# uninstallable: auto-determined as true

6. Items with installs array (trackable files/directories):

name: "file-tracked-app"
version: "1.0.0"
installer:
  type: "exe"
  location: "/packages/app-1.0.0.exe"
installs:
  - type: "file"
    path: "C:\Program Files\MyApp\app.exe"
    version: "1.0.0"
# uninstallable: auto-determined as true

Automatically Non-Uninstallable Items

1. OnDemand items (never considered "installed"):

name: "on-demand-script"
version: "1.0.0"
installer:
  type: "powershell"
  location: "/scripts/maintenance-script.ps1"
OnDemand: true
# uninstallable: auto-determined as false

2. EXE installers without uninstaller or tracking:

name: "simple-exe"
version: "1.0.0"
installer:
  type: "exe"
  location: "/packages/simple-app-1.0.0.exe"
# No uninstaller, registry check, or installs array
# uninstallable: auto-determined as false

3. PowerShell scripts without tracking:

name: "configuration-script"
version: "1.0.0"
installer:
  type: "powershell"
  location: "/scripts/configure-system.ps1"
# No tracking mechanism
# uninstallable: auto-determined as false

Implementation Details

The uninstallable check is enforced at multiple levels:

1. Status Check Level: CheckStatus() in the status package will return false for uninstall operations on non-uninstallable items
2. Installer Level: uninstallItem() will fail early if the item is marked as non-uninstallable
3. Removal Identification: identifyRemovals() will skip items that are not uninstallable

Use Cases

System Components

name: "windows-updates"
version: "2024.01"
installer:
  type: "msi"
  location: "/packages/critical-updates.msi"
uninstallable: false  # System critical, should never be removed

Development Tools

name: "visual-studio-code"
version: "1.85.0"
installer:
  type: "exe"
  location: "/packages/VSCode-1.85.0.exe"
uninstaller:
  location: "/packages/VSCode-uninstaller.exe"
  arguments: ["/SILENT"]
# uninstallable: auto-determined as true (has uninstaller)

Security Software

name: "antivirus-engine"
version: "2024.1.0"
installer:
  type: "msi"
  location: "/packages/antivirus-2024.1.0.msi"
uninstallable: false  # Prevent accidental removal of security software

This implementation provides both the flexibility of explicit control and the convenience of automatic determination, following Munki's proven approach to package uninstallability.