12 KiB
Dotnet
Local Development Workflow
For local development, it's recommended to use nix-shell to create a dotnet environment:
# shell.nix
with import <nixpkgs> {};
mkShell {
name = "dotnet-env";
packages = [
dotnet-sdk
];
}
Using many sdks in a workflow
It's very likely that more than one sdk will be needed on a given project. Dotnet provides several different frameworks (E.g dotnetcore, aspnetcore, etc.) as well as many versions for a given framework. Normally, dotnet is able to fetch a framework and install it relative to the executable. However, this would mean writing to the nix store in nixpkgs, which is read-only. To support the many-sdk use case, one can compose an environment using dotnetCorePackages.combinePackages
:
with import <nixpkgs> {};
mkShell {
name = "dotnet-env";
packages = [
(with dotnetCorePackages; combinePackages [
sdk_6_0
sdk_7_0
])
];
}
This will produce a dotnet installation that has the dotnet 6.0 7.0 sdk. The first sdk listed will have it's cli utility present in the resulting environment. Example info output:
$ dotnet --info
.NET SDK:
Version: 7.0.202
Commit: 6c74320bc3
Środowisko uruchomieniowe:
OS Name: nixos
OS Version: 23.05
OS Platform: Linux
RID: linux-x64
Base Path: /nix/store/n2pm44xq20hz7ybsasgmd7p3yh31gnh4-dotnet-sdk-7.0.202/sdk/7.0.202/
Host:
Version: 7.0.4
Architecture: x64
Commit: 0a396acafe
.NET SDKs installed:
6.0.407 [/nix/store/3b19303vwrhv0xxz1hg355c7f2hgxxgd-dotnet-core-combined/sdk]
7.0.202 [/nix/store/3b19303vwrhv0xxz1hg355c7f2hgxxgd-dotnet-core-combined/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 6.0.15 [/nix/store/3b19303vwrhv0xxz1hg355c7f2hgxxgd-dotnet-core-combined/shared/Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 7.0.4 [/nix/store/3b19303vwrhv0xxz1hg355c7f2hgxxgd-dotnet-core-combined/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 6.0.15 [/nix/store/3b19303vwrhv0xxz1hg355c7f2hgxxgd-dotnet-core-combined/shared/Microsoft.NETCore.App]
Microsoft.NETCore.App 7.0.4 [/nix/store/3b19303vwrhv0xxz1hg355c7f2hgxxgd-dotnet-core-combined/shared/Microsoft.NETCore.App]
Other architectures found:
None
Environment variables:
Not set
global.json file:
Not found
Learn more:
https://aka.ms/dotnet/info
Download .NET:
https://aka.ms/dotnet/download
dotnet-sdk vs dotnetCorePackages.sdk
The dotnetCorePackages.sdk_X_Y
is preferred over the old dotnet-sdk as both major and minor version are very important for a dotnet environment. If a given minor version isn't present (or was changed), then this will likely break your ability to build a project.
dotnetCorePackages.sdk vs dotnetCorePackages.runtime vs dotnetCorePackages.aspnetcore
The dotnetCorePackages.sdk
contains both a runtime and the full sdk of a given version. The runtime
and aspnetcore
packages are meant to serve as minimal runtimes to deploy alongside already built applications.
Packaging a Dotnet Application
To package Dotnet applications, you can use buildDotnetModule
. This has similar arguments to stdenv.mkDerivation
, with the following additions:
projectFile
is used for specifying the dotnet project file, relative to the source root. These usually have.sln
or.csproj
file extensions. This can be a list of multiple projects as well. Most of the time dotnet can figure this location out by itself, so this should only be set if necessary.nugetDeps
takes either a path to adeps.nix
file, or a derivation. Thedeps.nix
file can be generated using the script attached topassthru.fetch-deps
. This file can also be generated manually usingnuget-to-nix
tool, which is available in nixpkgs. If the argument is a derivation, it will be used directly and assume it has the same output asmkNugetDeps
.packNupkg
is used to pack project as anupkg
, and installs it to$out/share
. If set totrue
, the derivation can be used as a dependency for another dotnet project by adding it toprojectReferences
.projectReferences
can be used to resolveProjectReference
project items. Referenced projects can be packed withbuildDotnetModule
by setting thepackNupkg = true
attribute and passing a list of derivations toprojectReferences
. Since we are sharing referenced projects as NuGets they must be added to csproj/fsproj files asPackageReference
as well. For example, your project has a local dependency:
<ProjectReference Include="../foo/bar.fsproj" />
To enable discovery through projectReferences
you would need to add:
<ProjectReference Include="../foo/bar.fsproj" />
<PackageReference Include="bar" Version="*" Condition=" '$(ContinuousIntegrationBuild)'=='true' "/>
executables
is used to specify which executables get wrapped to$out/bin
, relative to$out/lib/$pname
. If this is unset, all executables generated will get installed. If you do not want to install any, set this to[]
. This gets done in thepreFixup
phase.runtimeDeps
is used to wrap libraries intoLD_LIBRARY_PATH
. This is how dotnet usually handles runtime dependencies.buildType
is used to change the type of build. Possible values areRelease
,Debug
, etc. By default, this is set toRelease
.selfContainedBuild
allows to enable the self-contained build flag. By default, it is set to false and generated applications have a dependency on the selected dotnet runtime. If enabled, the dotnet runtime is bundled into the executable and the built app has no dependency on Dotnet.useAppHost
will enable creation of a binary executable that runs the .NET application using the specified root. More info in Microsoft docs. Enabled by default.useDotnetFromEnv
will change the binary wrapper so that it uses the .NET from the environment. The runtime specified bydotnet-runtime
is given as a fallback in case no .NET is installed in the user's environment. This is most useful for .NET global tools and LSP servers, which often extend the .NET CLI and their runtime should match the users' .NET runtime.dotnet-sdk
is useful in cases where you need to change what dotnet SDK is being used. You can also set this to the result ofdotnetSdkPackages.combinePackages
, if the project uses multiple SDKs to build.dotnet-runtime
is useful in cases where you need to change what dotnet runtime is being used. This can be either a regular dotnet runtime, or an aspnetcore.dotnet-test-sdk
is useful in cases where unit tests expect a different dotnet SDK. By default, this is set to thedotnet-sdk
attribute.testProjectFile
is useful in cases where the regular project file does not contain the unit tests. It gets restored and build, but not installed. You may need to regenerate your nuget lockfile after setting this.disabledTests
is used to disable running specific unit tests. This gets passed as:dotnet test --filter "FullyQualifiedName!={}"
, to ensure compatibility with all unit test frameworks.dotnetRestoreFlags
can be used to pass flags todotnet restore
.dotnetBuildFlags
can be used to pass flags todotnet build
.dotnetTestFlags
can be used to pass flags todotnet test
. Used only ifdoCheck
is set totrue
.dotnetInstallFlags
can be used to pass flags todotnet install
.dotnetPackFlags
can be used to pass flags todotnet pack
. Used only ifpackNupkg
is set totrue
.dotnetFlags
can be used to pass flags to all of the above phases.
When packaging a new application, you need to fetch its dependencies. You can run nix-build -A package.fetch-deps
to generate a script that will build a lockfile for you. After running the script you should have the location of the generated lockfile printed to the console, which can be copied to a stable directory. Then set nugetDeps = ./deps.nix
and you're ready to build the derivation.
Here is an example default.nix
, using some of the previously discussed arguments:
{ lib, buildDotnetModule, dotnetCorePackages, ffmpeg }:
let
referencedProject = import ../../bar { ... };
in buildDotnetModule rec {
pname = "someDotnetApplication";
version = "0.1";
src = ./.;
projectFile = "src/project.sln";
nugetDeps = ./deps.nix; # File generated with `nix-build -A package.passthru.fetch-deps`.
projectReferences = [ referencedProject ]; # `referencedProject` must contain `nupkg` in the folder structure.
dotnet-sdk = dotnetCorePackages.sdk_6.0;
dotnet-runtime = dotnetCorePackages.runtime_6_0;
executables = [ "foo" ]; # This wraps "$out/lib/$pname/foo" to `$out/bin/foo`.
executables = []; # Don't install any executables.
packNupkg = true; # This packs the project as "foo-0.1.nupkg" at `$out/share`.
runtimeDeps = [ ffmpeg ]; # This will wrap ffmpeg's library path into `LD_LIBRARY_PATH`.
}
Dotnet global tools
.NET Global tools are a mechanism provided by the dotnet CLI to install .NET binaries from Nuget packages.
They can be installed either as a global tool for the entire system, or as a local tool specific to project.
The local installation is the easiest and works on NixOS in the same way as on other Linux distributions. See dotnet documention to learn more.
The global installation method
should also work most of the time. You have to remember to update the PATH
value to the location the tools are installed to (the CLI will inform you about it during installation) and also set
the DOTNET_ROOT
value, so that the tool can find the .NET SDK package.
You can find the path to the SDK by running nix eval --raw nixpkgs#dotnet-sdk
(substitute the dotnet-sdk
package for
another if a different SDK version is needed).
This method is not recommended on NixOS, since it's not declarative and involves installing binaries not made for NixOS, which will not always work.
The third, and preferred way, is packaging the tool into a Nix derivation.
Packaging Dotnet global tools
Dotnet global tools are standard .NET binaries, just made available through a special
NuGet package. Therefore, they can be built and packaged like every .NET application,
using buildDotnetModule
.
If however the source is not available or difficult to build, the
buildDotnetGlobalTool
helper can be used, which will package the tool
straight from its NuGet package.
This helper has the same arguments as buildDotnetModule
, with a few differences:
pname
andversion
are required, and will be used to find the NuGet package of the toolnugetName
can be used to override the NuGet package name that will be downloaded, if it's different frompname
nugetSha256
is the hash of the fetched NuGet package. Set this tolib.fakeHash256
for the first build, and it will error out, giving you the proper hash. Also remember to update it during version updates (it will not error out if you just change the version while having a fetched package in/nix/store
)dotnet-runtime
is set todotnet-sdk
by default. When changing this, remember that .NET tools fetched from NuGet require an SDK.
Here is an example of packaging pbm
, an unfree binary without source available:
{ buildDotnetGlobalTool, lib }:
buildDotnetGlobalTool {
pname = "pbm";
version = "1.3.1";
nugetSha256 = "sha256-ZG2HFyKYhVNVYd2kRlkbAjZJq88OADe3yjxmLuxXDUo=";
meta = with lib; {
homepage = "https://cmd.petabridge.com/index.html";
changelog = "https://cmd.petabridge.com/articles/RELEASE_NOTES.html";
license = licenses.unfree;
platforms = platforms.linux;
};
}