Python Installer

This is an installer designed for small python projects. You can drop it in the top level directory of your project and it will handle the installation for you. It's configurable by providing an installer.json file in the same directory. It features automatic cleanup on failure, and an uninstall option.

When no configuration is provided the default action is to install the top-level files into the proper application directory. Directories are not included by default, see the recurse config option.

Executable files are symlinked in the proper executable directory. When no configuration is provided, any file that is executable (chmod +x) is symlinked. If no executables are found, then any python file (.py) except files starting with '__' are used.

See the configuration options and install types below for more information.

This is not meant to replace other package managers such as pip, apt, or others. If your project has complex dependencies or build processes I would highly recommend making a proper package for it. This is for small projects with simple installation requirements.

I would recommend copying this to your project directory, renaming it to install, and making it executable (chmod +x install).

Install types:

###Global:

When install.py is ran with no arguments, the default install type is global. Global install looks for common application directories such as /usr/local/share, /usr/share, and /opt. Executables go in the common /bin directories, such as /usr/local/share/bin, /usr/local/bin or /usr/bin.

###Local:

When install.py --user is used, files are installed relative to the /home/user directory. Applications are installed in ~/.local/share, ~/local/share, and executables are installed in ~/bin, ~/.local/bin, and ~/local/bin.

When looking for proper directories, the first existing directory is used. Installations are aborted if no proper directory can be found.

Base directories can be explicitly set through configuration, which would override the standard directories.

A warning is emitted if the chosen executable path is not found in $PATH.

installer.json

Configuration is loaded from a config file called installer.json, which is JSON that supports C-style comments.

Configuration is merged with the defaults, so omitting an option means the default is automatically used.

Current configuration options and defaults:

    {
        // Default paths, files, behavior.
        "paths": {
            /* Override standard exe dirs and install_type choice with custom
               directory for installed executables.
            */
            "exe_base": null,

            /* Override standard app dirs and install_type choice with custom
               directory for application files.
            */
            "install_base": null,

            /*  Top level directory name under the main app dir.
                If not provided, it is determined by the cwd.
                So '/home/me/stuff/myapp' would make the toplevel 'myapp'.
                The final install directory would then be something like:
                    /usr/local/share/myapp
            */
            "toplevel": null,
            /*  Recurse the current directory when looking for included files.
                If true, this will recursively include files found in
                sub-directories.
            */
            "recurse": false,
            /*  Included file patterns (relative to the current dir).
                These are regex patterns.
                All relative paths that match these patterns will be included.
                By default, all files are included.
            */
            "files": [".+"],

            /*  Excluded file patterns (relative to the current dir).
                This is a list of regex patterns.
                All relative paths from included files that match these
                patterns will be excluded.
            */
            "excludes": [],

            /*  Executable files (for symlinking in the ../bin directory)
                When provided, file names relative to the top-level directory
                must be used, and automatic executable detection is disabled.
                File names must be found in the included files to work.
            */
            "executables": []
        },

        /*  Install type, 'global', 'local', or null.
            When provided, the command-line options have no effect and the
            install type is forced.
            The default is null, which means the install type depends on
            the user's command-line options.
        */
        "install_type": null
    }

Basic (not nested) C-style comments are currently supported by the installer, though they are not valid JSON (they are simply stripped before parsing). Any config options that are not recognized are ignored. Misconfiguration of known config settings will cause the installer to abort.

In the future, python dependencies may be handled automatically or at least warned about. For now you or your users will have to handle them, or use one of the "bigger" package managers. Sorry.

Automatic Cleanup:

If the installer encounters a fatal error during the installation, an attempt is made to remove the half-installed files. A warning is emitted to the user.

Uninstall/Remove:

When installation is successful, a file is created (installed_files.txt) that contains a list of all installed files with their full path. A copy of both the installer and installed_files.txt are installed along with the rest of the application to aid in future removal.

Running install.py remove or install.py uninstall will read the list of installed files, and attempt to remove them. Warnings are emitted if the files cannot be removed.

Compatibility:

This script uses Python 3 by default, but is compatible with Python 2. You can change the shebang line (#!/usr/bin/env python3) to suit your needs.

Installer Dependencies:

install.py currently depends on docopt to parse command-line options. You can get it by running pip install docopt.