.NET Core Runtime Cloud Native Buildpack

The .NET Core Runtime CNB provides a version of the .NET Core Runtime and sets the initial $DOTNET_ROOT location.

A usage example can be found in the samples repository under the dotnet-core/runtime directory.

Integration

The .NET Core Runtime CNB provides dotnet-runtime as a dependency. Downstream buildpacks, like Dotnet Publish and Dotnet Execute can require the dotnet-runtime dependency by generating a Build Plan TOML file that looks like the following:

[[requires]]

  # The name of the .NET Core Runtime dependency is "dotnet-runtime". This value is considered
  # part of the public API for the buildpack and will not change without a plan
  # for deprecation.
  name = "dotnet-runtime"

  # The version of the .NET Core Runtime dependency is not required. In the case it
  # is not specified, the buildpack will provide the default version, which can
  # be seen in the buildpack.toml file.
  # If you wish to request a specific version, the buildpack supports
  # specifying a semver constraint in the form of "6.*", "6.0.*", or even
  # "6.0.1".
  version = "6.0.1"

  # The .NET Core Runtime buildpack supports some non-required metadata options.
  [requires.metadata]

    # Setting the build flag to true will ensure that the .NET Core Runtime
    # dependency is available to subsequent buildpacks during their build phase.
    # Currently we do not recommend having your application directly interface with
    # the runtimes instead use the dotnet-core-sdk. However,
    # if you are writing a buildpack that needs to use the dotnet core runtime during
    # its build process, this flag should be set to true.
    build = true

    # Setting the launch flag to true will ensure that the .NET Core Runtime
    # dependency is available on the $DOTNET_ROOT for the running application. If you are
    # writing an application that needs to run .NET Core Runtime at runtime, this flag should
    # be set to true.
    launch = true

Specifying runtime versions

Self contained applications & Framework dependent applications

Be aware that specifying a dotnet runtime version for both framework dependent deployments and self contained deployments may result in errors if the selected runtimes do not match those used to build the application.

Source based applications

We do not recommend specifying a runtime version for source based workflows. Doing so could result in an incompatibility between the dotnet-sdk and its internal dotnet-runtime.

Usage

To package this buildpack for consumption:

$ ./scripts/package.sh -v <version>

Configuration

Specifying the .NET Framework Version through buildpack.yml configuration will be deprecated in .NET Core Runtime Buildpack v1.0.0.

To migrate from using buildpack.yml please set the following environment variables at build time either directly (ex. pack build my-app --env BP_ENVIRONMENT_VARIABLE=some-value) or through a project.toml file.

BP_DOTNET_FRAMEWORK_VERSION

The BP_DOTNET_FRAMEWORK_VERSION variable allows you to specify the version of .NET Core Runtime that is installed.

BP_DOTNET_FRAMEWORK_VERSION=5.0.4

This will replace the following structure in buildpack.yml:

dotnet-framework:
  version: "5.0.4"

For more information about version roll-forward logic, see the .NET documentation.

BP_DOTNET_ROLL_FORWARD

The BP_DOTNET_ROLL_FORWARD variable, when set to Disable, will only allow binding to the exact version specified. See .NET Core Runtime Binding for more information.

This variable has no purpose when using either buildpack.yml or BP_DOTNET_FRAMEWORK_VERSION to set the version, since those methods allow wildcarded version specifications. The version must be set using either the .runtimeconfig.json or vb|fs|csproj files.