Added guide for packaging .NET apps (#408)

Author: gridlocdev

docs/dotnet.rst

@@ -0,0 +1,132 @@
+Dotnet
+======
+
+Prerequisites
+~~~~~~~~~~~~~
+- :doc:`first-build`
+- The application is built with a Linux-compatible .NET desktop application framework such as:
+    - `Avalonia UI <https://avaloniaui.net/>`_
+    - `Uno Platform <https://platform.uno/>`_
+    - `Eto <https://github.com/picoe/Eto>`_
+    - `GTKSharp <https://github.com/GtkSharp/GtkSharp>`_
+- The application's source code is hosted on a Git server such as GitHub, GitLab, or Bitbucket
+
+Steps for Packaging
+~~~~~~~~~~~~~~~~~~~
+
+Installing Flatpak and Flatpak builder
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+1. Install Flatpak using the method provided for your distribution
+   `Flatpak - Quick Setup <https://flatpak.org/setup/>`_
+
+2. Install Flatpak Builder through your distribution package manager (e.g. ``apt`` / ``dnf``)
+
+.. code-block:: shell
+
+  sudo apt install flatpak-builder
+
+
+Creating the Flatpak
+^^^^^^^^^^^^^^^^^^^^
+
+A few placeholders have been used in the steps below, while going through the steps replace these with the ones respective to your project:
+
+- ``<app-id>``: The name of your Flatpak, see :ref:`conventions:application ids`.
+- ``<app-name>``: The name of the root folder of your app repository
+- ``<project-name>``: The name of your ``.csproj`` file
+- ``<git-url>``: The URL to the git repository of the project
+
+3.  Create a new folder somewhere different from your existing project
+
+4.  Create a YAML file titled ``<app-id>.yaml`` with the following example template, replacing the placeholders with the appropriate information. (Note: If your project file lives in a subfolder, be sure to include that in the build paths in this file and subsequent commands as well.): 
+
+.. code-block:: yaml
+
+  id: <app-id>
+  runtime: org.freedesktop.Platform
+  runtime-version: '23.08'
+  sdk: org.freedesktop.Sdk
+  sdk-extensions:
+    - org.freedesktop.Sdk.Extension.dotnet8
+  build-options:
+    prepend-path: "/usr/lib/sdk/dotnet8/bin"
+    append-ld-library-path: "/usr/lib/sdk/dotnet8/lib"
+    prepend-pkg-config-path: "/usr/lib/sdk/dotnet8/lib/pkgconfig"
+
+  command: <project-name>
+
+  finish-args:
+    - --device=dri
+    # TODO: Replace this with wayland and fallback-x11 once Wayland support
+    #       becomes available:
+    #       https://github.com/AvaloniaUI/Avalonia/pull/8003
+    - --socket=x11
+    - --share=ipc
+    - --env=DOTNET_ROOT=/app/lib/dotnet
+
+  modules:
+    - name: dotnet
+      buildsystem: simple
+      build-commands:
+      - /usr/lib/sdk/dotnet8/bin/install.sh
+
+    - name: <app-name>
+      buildsystem: simple
+      sources:
+        - type: git
+          url: <git-url>
+        - ./nuget-sources.json
+      build-commands:
+        - dotnet publish <project-name>.csproj -c Release --no-self-contained --source ./nuget-sources
+        - mkdir -p ${FLATPAK_DEST}/bin
+        - cp -r bin/Release/net8.0/publish/* ${FLATPAK_DEST}/bin
+
+.. note::
+
+    For providing access to other things such as the network or
+    filesystem, see :doc:`sandbox-permissions`
+
+5.  Copy and save the dotnet NuGet sources generator script
+    ``flatpak-dotnet-generator.py`` from the `Flatpak Builder Tools
+    repository <https://github.com/flatpak/flatpak-builder-tools>`_, to
+    the current folder, or run the following command to download it:
+
+.. code-block:: shell
+
+      wget https://raw.githubusercontent.com/flatpak/flatpak-builder-tools/master/dotnet/flatpak-dotnet-generator.py
+
+6.  Clone down your project repository to the folder
+
+.. code-block:: shell
+
+      git clone <git-url>
+
+7.  Install dependencies from Flathub
+
+.. code-block:: shell
+
+      flatpak-builder build-dir --user --install-deps-from=flathub --download-only <app-id>.yaml
+
+8.  Run the NuGet source config generator script ``flatpak-dotnet-generator.py`` with the following arguments:
+
+.. code-block:: shell
+
+      python3 flatpak-dotnet-generator.py --dotnet 8 --freedesktop 23.08 nuget-sources.json <app-name>/<project-name>.csproj
+
+9. Build and install using Flatpak builder
+
+.. code-block:: shell
+
+      flatpak-builder build-dir --user --force-clean --install --repo=repo <app-id>.yaml
+
+
+Testing the build
+^^^^^^^^^^^^^^^^^
+
+10. Run the installed Flatpak application
+
+.. code-block:: shell
+
+      flatpak run <app-id>
+

docs/guides.rst

@@ -11,6 +11,7 @@ standard guidance provided elsewhere in the Flatpak documentation.
 
    python
    electron
+   dotnet
    qt
    multiarch
    extension