Use a .nuspec file/script to automatically install nuget packages into a new project

Question

I am trying to automate the process of installing nuget packages into new visual studio projects. My idea is to reduce the time it takes to source all the packages via the nuget package manager, by specifying the packages in a custom file that can be run to install these packages. Therefore only requiring every new project to include this file and running it each time. I'm very new to nuget and have been assigned this task without much prior knowledge. I was advised that .nuspec route would lead me in the right direction, since it contains the meta data about a package. Although since consumers don't have direct access to the .nuspec file of a package, I am failing to understand how it can be used as part of this automation. I have also heard about automatic package restore, but since that only works for lost reference, I don't see how it will help in new projects that haven't necessarily referenced anything to do with that project.

Answer 1

note that you cannot simply drop a pre-built packages.config file into a new project and expect it to work. When installing, NuGet modifies the project file (.csproj) to include references and uses packages.config for downloading missing files (and update/conflict logic).

Using VS 2017 (released stable versions 15.2 and higher) and the PackageReference style of referencing projects, you can simply drop a Directory.Build.props file into the root of your solution containing all the projects you need:

<Project>
  <ItemGroup>
    <PackageReference Include="Autofac" Version="3.5.2 />
    <PackageReference Include="Topshelf" Version="3.2.0 />
  </ItemGroup>
</Project>

This will add these NuGet packages to all new projects in the solution without the need for the .csproj files to be modified. (note that after adding/editing this file, you need to close and re-open the solution. this should be fixed in the upcoming VS 2017 15.3 update for editing the file).

Answer 2

Nuget already supports automation of installation and we can use nuget commandline to achieve this

Everytime you add a nuget package in Visual Studio,it gets add to a file called packages.config file.

E.g. will look like this

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Autofac" version="3.5.2" targetFramework="net451" />  
  <package id="Microsoft.Owin" version="3.1.0" targetFramework="net452" />
  <package id="Microsoft.Owin.Host.HttpListener" version="3.0.1" targetFramework="net451" />
  <package id="Microsoft.Owin.Hosting" version="3.1.0" targetFramework="net452" />
  <package id="Newtonsoft.Json" version="9.0.1" targetFramework="net451" />
  <package id="Owin" version="1.0" targetFramework="net451" /> 
  <package id="Topshelf" version="3.2.0" targetFramework="net451" />
</packages>

Every project you have in your solution will have packages.config file. You can go to the parent folder of all the projects and simply run comand 'nuget restore', it will get all the packages for you.

For this to work, nuget.exe needs to be downloaded separately .More details on the nuget command line can be found here and here's the commandline reference

Edit:

Thanks @Martin Ullrich pointing out.Just to be clear, The above method will not add the references to project file automatically,it will only get the packages to the packages folder.In VS2017,the support is there which @Martin's answer addresses.

Hope this helps!