opkg create repository with multiple package version - yocto

What is the method used for distributing the same package but different versions through opkg. From what I understand opkg read an index file which it then uses to list and install the required package.
So far I have a repository that has multiple versions of the same package, but when I generate the index file it only has the latest version of the package. Thus the target platform cannot choose a specific version.
How can I implement this?

Related

NuGet Package Dependencies

Is it true that for every dependency that a package has on some other library, that those libraries need to be resolved and installed as well?
For example, I created a package which uses NLog, Postsharp and WindowsAzure.Storage:
Do clients of my package now have to install these packages as well? Why is it not possible to include these dependency DLLs within the package?
When a consumer installs your nuget package, nuget will automatically resolve and install the dependent packages as well.
It is possible to include the dlls within the package but it is not recommended. Because one way or another they will have to have references to the dlls they need to use your package( in this case NLog, PostSharp and WindowsAzure.Storage). Its better that the consumer have controll over what libraries are installed.
Another benefit of having dependencies via nuget is that the consumer may decide to install a newer version of WindowsAzure.Storage library which he can do easily when you don't have the dll injected into the package. Otherwise you can get into some messy assemblies runtime errors.
You control what your package contains via nuspec file used to build the nuget package.

What is the most standard way to get the latest version of an assembly solution-wide using NuGet?

My company is moving to using NuGet for our internal dependencies for desktop applications. This works fine for versioned imports, but in some cases (like during pre-Beta on a product) we'd like to grab the latest version of the dependency on our build servers and have the csproj files find it without issue.
We'd like to use automatic package restore, but that seems to be constrained by a specific version (as noted in this question). Using nuget restore followed by nuget update is also a possibility, but it doesn't seem to work solution-wide the way that restore does (and we have a couple dozen projects that have to share the same version of the same dependency).
Our best solution so far has been to add a hint path to the dependency binary in a non-versioned manner, i.e.,
<Reference Include="Dependency">
<SpecificVersion>False</SpecificVersion>
<HintPath>..\..\packages\Dependency\lib\net40\Dependency.dll</HintPath>
</Reference>
And use the pre-build event to run
nuget.exe install Dependency -NoCache -ExcludeVersion
Is there a better way to do this? It would be nice to do it the most standard way possible so that we can get tooling support and new developers to the project can more easily know how to add their own dependencies via NuGet.
As of Nuget.exe v2.8.3, there isn't any way to do a solution-wide restore and update (at least when not all the projects in a given folder hierarchy are part of a solution). We ended up using the workflow described in How do I update a single nuget package in a project from the command line?.

Get current version of package outside of Visual Studio

We are migrating over to using packages and NuGet for managing our dependencies on 3rd party components. This works well when referencing packages from within Visual Studio or building on the build server via msbuild.
However there are a number of files that we would like to access in our build scripts and installers. Previously these would be in source control with a well known path, now as the version of the package that we are consuming changes so the path to the package and hence the files is changing.
Is there a simple way I can get the path to a given package? The best solution I currently have is to search for all packages.config files and extract the package version from them.
Examples of the files that we need to access are
The NUnit console executable from the NUnit.Runners package for running unit tests.
License files from various packages that we redistribute with our installer.
Using the packages.config file is a pretty good solution. NuGet itself uses two approaches:
Reading the package information from the packages.config and using that to resolve to the packages path.
Enumerating all the directories in the packages directory.
You could use NuGet.Core to do either of the above if you do not want to write the code yourself. The classes that can be used are the DefaultPackagePathResolver, the PackageReferenceFile and LocalPackageRepository or SharedPackageRepository.
One problem with the second approach is that sometimes NuGet may occasionally leave behind NuGet packages that are not necessarily referenced by a project. In that case looking at the package directories may give you the incorrect information.
The only other approach I can think of might be to read the project files looking for the assembly references. Although that would not work for a solution level package such as NUnit.Runners.

Selective installation by using NuGet Package

I have created versions of NuGet packages,uploaded and it is working fine.
I have set of libraries in my package which has been populated in different directories inside the package.
Some users might require a particular directory of my NuGet package, and some of the libraries might not be needed. While installation I should prompt users that which part they need to install.
One Solution:Logical seperation of packages may be one solution. Like packing libraries in separate packages, and required packages can be installed.
But If it has been made selective installation, then it would be more easier. I have no idea whether NuGet have such an option. Any help would be appreciated.
NuGet has support for framework versions and platforms using conventions, you can read up on them in the docs. You can group them by target framework version or by target framework profile.
If you want to selectively install libraries, you are saying you want to selectively install dependencies: you should split them up in separate NuGet packages and declare your dependencies. These dependencies also can be grouped.
If your condition cannot be defined using framework version or profile, you should come up with your own entry-level NuGet packages and bring down the proper dependency chain (or use PowerShell hooks for this).

Varying dependencies depending on target project type

I have a package Ninject.Extensisons.Wcf which shall be installed differently depending on the type of the project to which it is installed. In the case where WCF is hosted in IIS (any project containing global.asax) a second package Ninject.Web.Common needs to be installed together with the package. For all other project types such as libraries, Console, WinForms, WPF applications this package should not be installed.
Is it somehow possible to achieve this e.g., using a powershell script? Or do I have to deploy two different packages in this case?
Unfortunately the current nuspec file does not provide for managing dependencies based on project type. We currently support targeting different framework versions, but that doesn't apply in your situation.
It is recommended that all dependencies are handled using package references. Although it would be technically possible to download and install a package using a PowerShell script, this is not supported and will most likely break in future versions.
First determine if it would actually be a problem to reference a web package in a non-web project. Just because assemblies are referenced, if they are not used, it should not have an impact.
If it turns out that having the web dependency causes undesirable side-effects, then you'll need to create separate packages.
I would split up your package into logical pieces. As you state, you have a package that is used by non-web projects. Web projects require a dependency on a different package.
So now you have 2 logical packages:
MyProject
MyProject.Web
MyProject (dependencies)
SomeOtherPackage
So a user would Install-Package MyProject for non-web projects, and Install-Package MyProject.Web for web projects.
At this point you would be done and everything would be fine. But I think you should consider another step. One of the issues I see with these split packages is that I have to figure out which particular package I need to install. I have to know that I need the "Web" version.
At this point, determine the typical use case for your package. If 90% of your users will be installing the Web version, then I would make a "meta" package that simply has dependencies for your common packages.
In your case I would make 3 packages:
MyProject (meta package)
MyProject.Web
MyProject.Web
MyProject.Core
SomeOtherPackage
MyProject.Core (common non-web package)
By creating the "meta" package, you can reserve the "short" package name for the most common case. This meta package only has dependencies to other packages.
A good example of this is the SignalR package.
Hope this was helpful.