Add buildpack name to buildpack and builder metadata

[ekcasey]

Description

In buildpack.toml there is an optional name field that contains the human-readable name of a buildpack. This is useful information for certain types of autmation (for example, generating release notes for a builder or buildpack). This information should be available in a label on buildpackage and builder images.

Proposed solution

Buildpackage Metadata

Add name to io.buildpacks.buildpackage.metadata on buildpack images

{
  "id": "paketo-buildpacks/java",
  "name": "Paketo Java Buildpack",
  "version": "4.6.0",
  "homepage": "https://github.com/paketo-buildpacks/java",
  "stacks": [
    {
      "id": "io.buildpacks.stacks.bionic"
    }
  ]
}

Buildpack Layers Metadata

Add name to each buildpack in io.buildpacks.buildpack.layers

{
  "paketo-buildpacks/apache-tomcat": {
    "3.1.0": {
      "api": "0.4",
      "name": "Paketo Apache Tomcat Buildpack",
      "stacks": [
        {
          "id": "io.buildpacks.stacks.bionic"
        }
      ],
      "layerDiffID": "sha256:7b92482a317633951cde946c993546de25ac509b036f99b5b020eb4a02079d70",
      "homepage": "https://github.com/paketo-buildpacks/apache-tomcat"
    }
  },
  "paketo-buildpacks/azure-application-insights": {
    "3.0.0": {
      "api": "0.4",
      "name": "Paketo Azure Application Insights Buildpack",
      "stacks": [
        {
          "id": "io.buildpacks.stacks.bionic"
        }
      ],
      "layerDiffID": "sha256:dcc047af83b728bfe085efc4834f1d6e51c6e5d706c70b47a59efac8ec5e7151",
      "homepage": "https://github.com/paketo-buildpacks/azure-application-insights"
    }
  },
  {} # etc.
}

Builder Metadata

Add name to each buildpack in io.buildpacks.builder.metadata

{
  "description": "Ubuntu bionic base image with buildpacks for Java, .NET Core, NodeJS, Go, Ruby, NGINX and Procfile",
  "buildpacks": [
    {
      "id": "paketo-buildpacks/dotnet-core",
      "name": "Paketo .NET Core Buildpack",
      "version": "0.0.9",
      "homepage": "https://github.com/paketo-buildpacks/dotnet-core"
    },
    {
      "id": "paketo-buildpacks/dotnet-core-sdk",
      "name": "Paketo .NET SDK Buildpack",
      "version": "0.0.196",
      "homepage": "https://github.com/paketo-buildpacks/dotnet-core-sdk"
    },
    {} # etc.
    ],
    "stack": {},
    "lifecycle": {},
    "createdBy": {}
}

Describe alternatives you've considered

Maybe if the name is present in io.buildpacks.buildpack.layers we don't need it in io.buildpacks.buildpackage.metadata or io.buildpacks.builder.metadata? I couldn't quite figure out the organizing principle for what we normalized or denormalized where. I decided name was most like homepage which we repeat in each of these labels.

Additional context

• This would affect the label schemas in a future builder extension specification