chef_client.nsis

Name "Chef Client Installation"
OutFile "install-chef-client.exe"

; Constants
!define CHEF_VERSION "16.3.73"
!define CHEF_MSI "chef-client-${CHEF_VERSION}.msi"

; Variables
Var ChefClientInstalled

; Pages
Page Custom CheckChefClientInstalled
Page InstFiles

; Custom page
Function CheckChefClientInstalled
  System::Call 'Kernel32::GetModuleHandle(w "chef-client.exe") i .R0'
  StrCmp $R0 0 ChefClientNotInstalled ChefClientInstalled
FunctionEnd

; Installation page
Function InstFiles
  File "${CHEF_MSI}"
  ExecWait 'msiexec /i "${CHEF_MSI}" /qn'
FunctionEnd

; Uninstallation page
Function un.onInit
  System::Call 'Kernel32::GetModuleHandle(w "chef-client.exe") i .R0'
  StrCmp $R0 0 NoChefClient un.ChefClientInstalled
FunctionEnd

; Labels
Label ChefClientNotInstalled
  StrCpy $ChefClientInstalled 0
  Goto InstFiles
Label ChefClientInstalled
  MessageBox MB_OK "Chef client is already installed."
  Abort
Label NoChefClient
  MessageBox MB_OK "Chef client is not installed."
  Abort