This script generates MSI packages from a JSON description file and one or more staging directories.

This script creates MSI installer packages. It supports both WiX and msitools. The installers may have one or more parts. Understanding the installer is perhaps best learned through an example.

Suppose that once installed your application looks like this:

c:\Program Files\MyProg\program.exe
c:\Program Files\MyProg\resources\image.png

In order to achieve this you'd need to create two things. The first is a staging directory that consists of the files below MyProg in the layout they will exist in the final result. People familiar with the way Unix works can consider this as roughly the result of doing an install with DESTDIR pointing to the staging directory. In addition you need a JSON file describing all metadata required to create the install, let's call this myprog.json and a license file License.rtf.

To get the installer started you'd need to create a file and directory layout like this in a directory of your choice:

myprog.json
License.rtf
staging\program.exe
staging\resources\image.png

As you can tell, eventually the contents of staging subdir will be installed in c:\Program Files\MyProg. The contents of myprog.json would look like this:

{
    "upgrade_guid": "YOUR-GUID-HERE",
    "version": "1.0.0",
    "product_name": "Product name here",
    "manufacturer": "Your organization's name here",
    "name": "Name of product here",
    "name_base": "myprog",
    "comments": "A comment describing the program",
    "installdir": "MyProg",
    "license_file": "License.rtf",
    "parts": [
        {
         "id": "MainProgram",
         "title": "Program name",
         "description": "The MyProg program",
         "absent": "disallow",
         "staged_dir": "staging"
        }
    ]
}

This is all you need. The installer is built by executing this command in the top level directory:

python createmsi.py myprog.json

Once the script finishes the installer will be written into myprog-1.0.0-64.msi (when run on a 64 bit machine).

Each entry in the parts array defines a subpart in the installer that the user can choose whether to install. Each of these entries points to a separate staging directory with the contents of that part. Thus if you have a project that ships a DLL for using as well as an optional development package with an import library and a header, you'd need to split your files in two directories like this:

staging_main\foo.dll
staging_deve\foo.lib
staging_deve\foo.h

Then you'd have two entries in the parts array, one pointing to staging_main and the other pointing to staging_deve. Set the value of absent to disallow for components that are mandatory, the user won't be able to deselect them so they will always be installed.. If the user intalls both components, the final result would look like this:

c:\program files\foo\foo.dll
c:\program files\foo\foo.lib
c:\program files\foo\foo.h

Note how the files end up in the same directory.