Advanced Workflows¶

Multi-Architecture Images¶

Why?¶

RDK devices vary:

• ARMv7 (most common)
• ARM64 / AARCH64 (newer 64-bit SoCs)
• x86 (dev environments)

Manifest Creation¶

docker manifest create ghcr.io/org/app:1.2.3 \
  ghcr.io/org/app:arm64-1.2.3 ghcr.io/org/app:armv7-1.2.3 ghcr.io/org/app:amd64-1.2.3

docker manifest push ghcr.io/org/app:1.2.3

QEMU Emulation¶

Used when building non-native architectures:

- uses: docker/setup-qemu-action@v3

Image Size Optimization¶

1. Use scratch¶

Smallest possible image

2. Multi-stage builds¶

FROM rust:1.78 AS builder
WORKDIR /app

COPY Cargo.toml Cargo.lock ./
COPY src ./src
RUN cargo build --release

FROM scratch
COPY --from=builder /app/target/release/my-app /my-app
ENTRYPOINT ["/my-app"]

3. Strip binaries¶

strip target/release/my-app

4. Avoid unnecessary files¶

• No package managers
• No debug symbols
• No logs
• No unnecessary tools/libraries (e.g. curl, busybox, etc...)

Alpine Linux vs Scratch Images¶

GitHub Actions Optimizations¶

Caching¶

--cache-from type=gha
--cache-to type=gha,mode=max

Parallel Target Arch Builds¶

strategy:
  matrix:
    arch: [arm64, armv7, amd64]

OCI Image Metadata (Best Practices)¶

Include rich metadata:

LABEL org.opencontainers.image.title="RDK App"
LABEL org.opencontainers.image.description="Dashboard UI for RDK"
LABEL org.opencontainers.image.vendor="Your Company"
LABEL org.opencontainers.image.licenses="Apache-2.0"

GHCR (OCI Registry) Best Practices¶

• Use public images where possible
• Add descriptions in repo settings
• Use consistent naming, e.g. ghcr.io/org/app

Optional Enhancements¶

• SBOM generation (Software Bill of Materials)
• Image signing (cosign)
• Vulnerability scanning

Key Takeaways¶

• Multi-arch support improves portability
• Smaller images = faster deployment + better security
• CI/CD pipelines should be optimized and cached
• Metadata improves maintainability and traceability