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Supported Releases

CodenameUbuntu Version
focal20.04 LTS
jammy22.04 LTS
mantic23.10
noble24.04 LTS
oracular24.10

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Dockerfile

# syntax=docker/dockerfile:1.6
FROM ubuntu:noble

RUN --mount=type=secret,id=rootio_api_key \
    DEBIAN_FRONTEND=noninteractive apt-get update && \
    # Install dependencies for adding repositories
    apt-get install -y --no-install-recommends gnupg ca-certificates && \
    \
    # Initialize keyring and add Root.io GPG key
    mkdir -p /etc/apt/keyrings && \
    echo "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" \
    | base64 -d | gpg --dearmor -o /etc/apt/keyrings/rootio.gpg && \
    \
    # Write API key to auth.conf.d (never embedded in the source URL)
    mkdir -p /etc/apt/auth.conf.d && \
    printf "machine pkg.root.io\nlogin root\npassword %s\n" \
    "$(cat /run/secrets/rootio_api_key)" > /etc/apt/auth.conf.d/rootio.conf && \
    chmod 600 /etc/apt/auth.conf.d/rootio.conf && \
    \
    # Add Root.io APT repository
    echo "deb [signed-by=/etc/apt/keyrings/rootio.gpg] https://pkg.root.io/ubuntu/noble noble main" \
    > /etc/apt/sources.list.d/rootio.list && \
    \
    DEBIAN_FRONTEND=noninteractive apt-get update && \
    \
    # Install packages, preferring Root.io patched versions when available
    for pkg in curl git openssl wget bash tini; do \
    if apt-cache show "rootio-$pkg" >/dev/null 2>&1; then \
    apt-get install -y --no-install-recommends "rootio-$pkg"; \
    else \
    apt-get install -y --no-install-recommends "$pkg"; \
    fi; \
    done && \
    \
    # Remove credentials and clean up
    rm -f /etc/apt/auth.conf.d/rootio.conf && \
    rm -rf /var/lib/apt/lists/*

CMD ["/bin/bash"]
Replace both occurrences of noble with your target release codename.

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Build

export ROOTIO_API_KEY="your-api-token"

DOCKER_BUILDKIT=1 docker build \
  --secret id=rootio_api_key,env=ROOTIO_API_KEY \
  -t my-app:latest .

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How It Works

  1. gnupg and ca-certificates are installed from the upstream Ubuntu registry first.
  2. Root.io’s GPG key is imported to /etc/apt/keyrings/rootio.gpg for package signature verification.
  3. The API key is written to /etc/apt/auth.conf.d/rootio.conf — APT reads it automatically and it never appears in the source URL.
  4. For each package, apt-cache show rootio-<pkg> checks if a Root-patched version exists. If yes, the patched version is installed; if not, the standard upstream package is used.
  5. The auth file is removed in the same RUN layer, so credentials are never persisted in the image.

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CI/CD Integration

- name: Build container image
  env:
    ROOTIO_API_KEY: ${{ secrets.ROOTIO_API_KEY }}
  run: |
    DOCKER_BUILDKIT=1 docker build \
      --secret id=rootio_api_key,env=ROOTIO_API_KEY \
      -t my-app:latest .

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Troubleshooting

IssueSolution
401 Unauthorized on apt-get updateVerify ROOTIO_API_KEY is set and passed via --secret
rootio-<package> not foundRoot hasn’t patched this package yet — the fallback installs the upstream version
GPG key import failsEnsure gnupg and ca-certificates are installed before the key import step
--secret flag not recognizedPrepend DOCKER_BUILDKIT=1 to your build command