Installing packages

Often variants will need to install additional software to satisfy build or runtime dependencies. You can have APT packages installed using the apt directives.

Background

Given examples/hello-world-c as a working directory.

Install additional build dependencies

Given this "blubber.yaml"

version: v4
variants:
  build:
    base: debian:bullseye
    apt:
      packages:
        - gcc
        - libc6-dev

When you build the "build" variant

Then the image will have the following files in "/usr/bin"

gcc

Install from additional APT sources

Given this "blubber.yaml"

version: v4
variants:
  build:
    base: docker-registry.wikimedia.org/golang1.21:1.21-1-20240609
    apt:
      sources:
        - url: https://apt.wikimedia.org/wikimedia
          distribution: bullseye-wikimedia
          components:
            - thirdparty/amd-rocm54
      packages:
        bullseye-wikimedia: # you may use an explicit distribution/release name like so
          - fake-libgcc-7-dev

When you build the "build" variant

Then the image will have the following files in "/usr/share/doc/fake-libgcc-7-dev"

copyright

Provide a public key for an additional APT source

Given this "blubber.yaml"

version: v4
base: docker-registry.wikimedia.org/bookworm:20250601
variants:
  build:
    apt:
      sources:
        - url: https://packages.microsoft.com/debian/12/prod
          distribution: bookworm
          components: [main]
          signed-by: |
            -----BEGIN PGP PUBLIC KEY BLOCK-----
            Version: GnuPG v1.4.7 (GNU/Linux)

            mQENBFYxWIwBCADAKoZhZlJxGNGWzqV+1OG1xiQeoowKhssGAKvd+buXCGISZJwT
            LXZqIcIiLP7pqdcZWtE9bSc7yBY2MalDp9Liu0KekywQ6VVX1T72NPf5Ev6x6DLV
            7aVWsCzUAF+eb7DC9fPuFLEdxmOEYoPjzrQ7cCnSV4JQxAqhU4T6OjbvRazGl3ag
            OeizPXmRljMtUUttHQZnRhtlzkmwIrUivbfFPD+fEoHJ1+uIdfOzZX8/oKHKLe2j
            H632kvsNzJFlROVvGLYAk2WRcLu+RjjggixhwiB+Mu/A8Tf4V6b+YppS44q8EvVr
            M+QvY7LNSOffSO6Slsy9oisGTdfE39nC7pVRABEBAAG0N01pY3Jvc29mdCAoUmVs
            ZWFzZSBzaWduaW5nKSA8Z3Bnc2VjdXJpdHlAbWljcm9zb2Z0LmNvbT6JATUEEwEC
            AB8FAlYxWIwCGwMGCwkIBwMCBBUCCAMDFgIBAh4BAheAAAoJEOs+lK2+EinPGpsH
            /32vKy29Hg51H9dfFJMx0/a/F+5vKeCeVqimvyTM04C+XENNuSbYZ3eRPHGHFLqe
            MNGxsfb7C7ZxEeW7J/vSzRgHxm7ZvESisUYRFq2sgkJ+HFERNrqfci45bdhmrUsy
            7SWw9ybxdFOkuQoyKD3tBmiGfONQMlBaOMWdAsic965rvJsd5zYaZZFI1UwTkFXV
            KJt3bp3Ngn1vEYXwijGTa+FXz6GLHueJwF0I7ug34DgUkAFvAs8Hacr2DRYxL5RJ
            XdNgj4Jd2/g6T9InmWT0hASljur+dJnzNiNCkbn9KbX7J/qK1IbR8y560yRmFsU+
            NdCFTW7wY0Fb1fWJ+/KTsC4=
            =J6gs
            -----END PGP PUBLIC KEY BLOCK-----
      packages: [dotnet-sdk-8.0]
    entrypoint: [dotnet, --version]

When you build and run the "build" variant

Then the entrypoint will have run successfully.