Understanding Chocolatey

index

What is Chocolatey (Choco)?
But I want my own Choco Server
What things are inside .nupkg
Two Important Files for jnuget
References

What is Chocolatey (Choco)?

If you are familiar with apt-get command line program in Linux, you may had used apt-get install, apt-get update for managment your Linux software, but how about in Windows?

Choco is a package manager for Windows and it has similar functions compare to apt-get. It allows you to install, upgrade, configure, and uninstall Windows software. For example, just simplly type choco install PROGRAM_NAME in command line, choco will automatelly install the program that you need.

But I want my own Choco Server

if your company or your group requires deploying software fast, easy and secure, you may neet to set up your own Choco Server. Then the following packages you would need:

Understanding Choco's code

Using "choco install" command as example

The entry point of choco is function private static void Main(string[] args) which in file src/chocolatey.console/Program.cs.

            
public sealed class Program
{
    // ReSharper disable InconsistentNaming
    private static void Main(string[] args)
    // ReSharper restore InconsistentNaming
    {
        try
        {
            add_assembly_resolver();

            string loggingLocation = ApplicationParameters.LoggingLocation;
            //no file system at this point
            if (!Directory.Exists(loggingLocation)) Directory.CreateDirectory(loggingLocation);

            ......

After do some variables and directories checking, the argument of command input will pass to ConfigurationBuilder.set_up_configuration(args,config,container,license,warning => {warnings.Add(warning);});)
This function will parse argument, configurate file path and set environment values.

            
public static void set_up_configuration(IList args, ChocolateyConfiguration config, Container container, ChocolateyLicense license, Action notifyWarnLoggingAction)
{
    var fileSystem = container.GetInstance();
    var xmlService = container.GetInstance();
    var configFileSettings = get_config_file_settings(fileSystem, xmlService);
    // must be done prior to setting the file configuration
    add_or_remove_licensed_source(license, configFileSettings);
    set_file_configuration(config, configFileSettings, fileSystem, notifyWarnLoggingAction);
    ConfigurationOptions.reset_options();
    set_global_options(args, config, container);
    set_environment_options(config);
    EnvironmentSettings.set_environment_variables(config);
    // must be done last for overrides
    set_licensed_options(config, license, configFileSettings);
    // save all changes if there are any
    set_config_file_settings(configFileSettings, xmlService, config);
    set_hash_provider(config, container);
}

Following, a run() function which belong to src\chocolatey\infrastructure.app\runners\ConsoleApplication.cs will handle the input command

            
        ......
        AssemblyFileExtractor.extract_all_resources_to_relative_directory(fileSystem, Assembly.GetAssembly(typeof(ChocolateyResourcesAssembly)), ApplicationParameters.InstallLocation, folders, ApplicationParameters.ChocolateyFileResources);

        var application = new ConsoleApplication();
        application.run(args, config, container);
    }
    catch (Exception ex)
    {
        if (ApplicationParameters.is_debug_mode_cli_primitive())
        ......

The next run() function (src\chocolatey\infrastructure.app\runners\GenericRunner.cs) will be called and continue to execute the input command

            
        ......
        commandArgs.Add(arg);
    }

    var runner = new GenericRunner();
    runner.run(config, container, isConsole: true, parseArgs: command =>
        {
            ConfigurationOptions.parse_arguments_and_update_configuration(
                commandArgs,
                config,
                ......

The seecond run() function invokes find_command(config, container, isConsole, parseArgs); and gets an instance which ontains run(chocolatey.infrastructure.app.configuration.ChocolateyConfiguration configuration) chocolatey/infrastructure.app/commands/ChocolateyInstallCommand.cs. This run() function is specifit for install command Continuing the install command, get_script_for_action() function will be called for determining which power shell script should be used.

            
private string get_script_for_action(PackageResult packageResult, CommandNameType command)
{
    var file = "chocolateyInstall.ps1";
    switch (command)
    {
        case CommandNameType.uninstall:
            file = "chocolateyUninstall.ps1";
            break;

        case CommandNameType.upgrade:
            file = "chocolateyBeforeModify.ps1";
            break;
    }
    ......

Another core file is Nuget.Core. Nuget is a Microsoft platform package manager. Yes, Chocolatey is using Nuget.Core to connect packages source server to get and unzip .nupkg

The enviroument configuration file is src/chocolatey/infrastructure.app/ApplicationParameters.cs. It points out where to store temprary file, whate kinds of files it should look, and where to log. src/chocolatey/infrastructure.app/configuration/chocolatey.config indicate the .nuget source server address.

            
        ......
        <add key="proxyUser" value="" />
        <add key="proxyPassword" value="" />
    </config>
    <sources>
        <source id="chocolatey" value="https://chocolatey.org/api/v2/" />
    </sources>
    <features>
        <feature name="checksumFiles" enabled="true" />
        <feature name="autoUninstaller" enabled="false" />
        ......

What things are inside .nupkg

In comment, .nupkg contains .nuspec (specification of the software you want to install), and chocolateyInstall.ps1/chocolateyUninstall.ps1 (powershell script for actual choco command)

Let's look at .nuspec file. You can find more detail in .nuspec Reference This file is in xml format and requires 4 elements <id>, <version>, <description>, and <authors> The following is a basic vlv.nuspec for VLC Media Player

            
<?xml version="1.0" encoding="utf-8"?>
<package xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
    <metadata>
        <id>vlc</id>
        <version>2.2.4.20161210</version>
        ......
        <authors>VideoLAN Organization</authors>
        <description>
            ......
        </description>
        ......
    </metadata>
</package>

Now switch to file chocolateyInstall.ps1. The core code is very simple. In src\chocolatey\infrastructure.app\templates, you will find our more detail of chocolateyInstall.ps1

            
$packageArgs = @{
  packageName            = 'packagename'
  fileType               = 'msi'
  url                    = 'https://example.com/where.to.download.32bit.msi'
  url64bit               = 'https://example.com/where.to.download.64bit.msi'
  ......
}
Install-ChocolateyPackage @packageArgs

Two Important Files for jnuget

jnuget is a JAVA Web Application which functioning as Nuget in JSP server. In our case, jnuget is used for holding and managing our software. There are two files are very important to jnuget. The first one is jnuget.users.xml for users setting up. Another one is jnuget.config.xml which indicating your software holding directory.

            
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!-- jnuget.users.xml -->
<users>
    <user name="admin" password="1234">
        <role>jnuget-admin</role>
    </user>
</users>

            
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!-- jnuget.config.xml -->
<options>
    <storages>
        <storage class="ru.aristar.jnuget.sources.ClassicPackageSource" indexed="false" storageName="DefaultSource" public="true" canPush="true" canDelete="true">
            <properties>
                <property name="folderName" value="${nuget.home}/Packages/"/>
            </properties>
        </storage>
    </storages>
</options>

Jerry Guan