README.md

.NET Core SDK image

This repository contains the source for building .NET Core applications as a reproducible container image using source-to-image. The resulting image can be run using docker/podman.

Usage

To build a simple dotnet-sample-app application using standalone S2I and then run the resulting image with docker/podman execute:

```
$ sudo s2i build git://github.com/redhat-developer/s2i-dotnetcore --context-dir=3.0/build/test/asp-net-hello-world dotnet/dotnet-30-rhel7 dotnet-sample-app
$ sudo docker run -p 8080:8080 dotnet-sample-app
```

Accessing the application:

HTTP:

$ curl http://127.0.0.1:8080

Incremental builds

The s2i image supports incremental builds. For incremental builds, NuGet packages will be re-used. To keep NuGet packages so they can be reused, you must set DOTNET_INCREMENTAL to true.

Repository organization

• Dockerfile.rhel7

  RHEL 7 based Dockerfile. In order to perform build or test actions on this Dockerfile you need to run the action on a properly subscribed RHEL machine.

• Dockerfile.rhel8

  UBI 8 / RHEL 8 based Dockerfile. No RHEL subscription is required, but without one only UBI RPMs can be added to the container.

• Dockerfile

  CentOS based Dockerfile.

• root/usr/bin/

  This folder contains common scripts.

• s2i/bin/

  This folder contains scripts that are run by S2I:

  • assemble

    Used to install the sources into the location where the application will be run and prepare the application for deployment

  • run

    This script is responsible for running the application

  • usage

    This script prints the usage of this image.

• contrib/

  This folder contains scripts under the app source tree.

• test/

  This folder contains S2I dotnet sample applications.

  • helloworld/

    .Net Core "Hello World" used for testing purposes by the S2I test framework.

  • qotd/

    .Net Core Quote of the Day example app used for testing purposes by the S2I test framework.

  • asp-net-hello-world/

    ASP .Net hello world example app used for testing purposes by the S2I test framework.

  • asp-net-hello-world-envvar/

    ASP .Net hello world example app used for testing purposes by the S2I test framework.

Environment variables

To set these environment variables, you can place them as a key value pair into a .s2i/environment file inside your source code repository.

• DOTNET_STARTUP_PROJECT

  Used to select the project to run. This must be a project file (e.g. csproj, fsproj) or a folder containing a single project file. Defaults to ..

• DOTNET_ASSEMBLY_NAME

  Used to select the assembly to run. This must NOT include the .dll extension. Set this to the output assembly name specified in the project file (PropertyGroup/AssemblyName). This defaults to the project filename.

• DOTNET_PUBLISH_READYTORUN

  When set to true, the application will be compiled ahead-of-time. This reduces startup time by reducing the amount of work the JIT needs to do when the application is loading. Defaults to ``.

• DOTNET_RESTORE_SOURCES

  Used to specify the list of NuGet package sources used during the restore operation. This overrides all of the sources specified in the NuGet.config file. This variable cannot be combined with DOTNET_RESTORE_CONFIGFILE.

• DOTNET_RESTORE_CONFIGFILE

  Specifies a NuGet.Config file to be used for restore operations. This variable cannot be combined with DOTNET_RESTORE_SOURCES.

• DOTNET_RESTORE_DISABLE_PARALLEL

  When set to true disables restoring multiple projects in parallel. This reduces restore timeout errors when the build container is running with low cpu limits. Defaults to false.

• DOTNET_TOOLS

  Used to specify a list of .NET tools to install before building the app. It is possible to install a specific version by postpending the package name with @<version>. Defaults to ``.

• DOTNET_NPM_TOOLS

  Used to specify a list of npm packages to install before building the app. Defaults to ``.

• DOTNET_TEST_PROJECTS

  Used to specify the list of test projects to run. This must be project files or folders containing a single project file. dotnet test is invoked for each item. Defaults to ``.

• DOTNET_VERBOSITY

  Used to specify the verbosity of the dotnet build commands. When set, the environment variables are printed at the start of the build. This variable can be set to one of the msbuild verbosity values (q[uiet], m[inimal], n[ormal], d[etailed], and diag[nostic]). Defaults to ``.

• DOTNET_CONFIGURATION

  Used to run the application in Debug or Release mode. This should be either Release or Debug. This is passed to the dotnet publish invocation. Defaults to Release.

• ASPNETCORE_URLS

  This variable is set to http://*:8080 to configure ASP.NET Core to use the port exposed by the image.

• HTTP_PROXY, HTTPS_PROXY

  Configures the HTTP/HTTPS proxy used when building and running the application.

• DOTNET_RM_SRC

  When set to true, the source code will not be included in the image. Defaults to ``.

• DOTNET_INCREMENTAL

  When set to true, the NuGet packages will be kept so they can be re-used for an incremental build. Defaults to false.

• NPM_MIRROR

  Use a custom NPM registry mirror to download packages during the build process.

• DOTNET_STARTUP_ASSEMBLY

  Used to specify the path of the entrypoint assembly within the source repository. When set, the source repository must contain a pre-built application. Defaults to ``.

• DOTNET_PACK

  When set to true creates a tar.gz file at /opt/app-root/app.tar.gz that contains the published application.

• DEV_MODE

  When set to true, the application restart automatically when the source code changes. dotnet run is used to start the application.

• DOTNET_USE_POLLING_FILE_WATCHER

  This is set to true to ensure the dotnet watch command works in a container. This command is not used by the default scripts.

NPM

Typical modern web applications rely on javascript tools to build the front-end. The image includes npm (node package manager) to install these tools. Packages can be installed by setting DOTNET_NPM_TOOLS and by calling npm install in the build process.