🚀 Why Docker for Swift on AL2023?

AL2023 has no official Swift toolchain → library mismatches, no RPM packages.
Docker solves this by running Swift in a compatible Ubuntu userland (or nightly images) while still using the host’s Linux kernel.
Overhead is tiny → CPU/memory nearly native, only extra disk space for images.

🛠 Step 1: Install Docker on AL2023

sudo dnf update -y
sudo dnf install -y docker
sudo systemctl enable --now docker
sudo usermod -aG docker $USER
newgrp docker
docker version   # verify

🛠 Step 2: Choose a Swift Docker image

Two main sources:

Stable releases (safe for production)
- Hosted at hub.docker.com/_/swift
- Example:
```
docker pull swift:6.1.2-jammy-slim
```
Nightlies / unreleased versions (e.g. Swift 6.2)
- Hosted at hub.docker.com/r/swiftlang/swift
- Example:
```
docker pull swiftlang/swift:nightly-6.2-jammy
```

🛠 Step 3: Run Swift interactively

docker run --rm -it swift:6.1.2-jammy swift --version

(or swap in swiftlang/swift:nightly-6.2-jammy)

🛠 Step 4: Develop with your source code

Mount your project into the container:

mkdir ~/swift-app && cd ~/swift-app

docker run --rm -it -v "$PWD":/app -w /app swift:6.1.2-jammy \
  bash -lc 'swift package init --type executable && swift build && swift test'

Build/run repeatedly by re-invoking docker run ....

🛠 Step 5: Package for deployment (multi-stage Dockerfile)

Example Dockerfile:

# --- Build stage ---
FROM swift:6.1.2-jammy AS builder
WORKDIR /build
COPY . .
RUN swift build -c release

# --- Runtime stage ---
FROM ubuntu:22.04
RUN apt-get update && apt-get install -y --no-install-recommends \
    libicu70 libxml2 libbsd0 zlib1g tzdata ca-certificates && \
    rm -rf /var/lib/apt/lists/*
WORKDIR /app
COPY --from=builder /build/.build/release/YourTarget /usr/local/bin/app
EXPOSE 8080
CMD ["/usr/local/bin/app"]

Build & run:

docker build -t my-swift-app .
docker run --rm -p 8080:8080 my-swift-app

🛠 Step 6: (Optional) Push to ECR

For production, push the image to Amazon ECR, then pull/run it on EC2 or ECS/Fargate.

✅ Key Takeaways

Use Docker to sidestep missing Swift support on AL2023.
Pick swift:<version>-jammy for stable, or swiftlang/swift:nightly-6.2-* for bleeding edge.
Overhead is negligible compared to native execution.
Develop by mounting code into containers, deploy with a multi-stage Dockerfile.

brennanMKE/README.md