Self hosting SvelteKit SSR applications with Bun latest, with Health-checking.

Dockerfile

ARG BUN_VERSION=latest
FROM oven/bun:${BUN_VERSION} AS builder

WORKDIR /app
ENV NODE_ENV=production

# Copy package files first
COPY --link bun.lock package.json ./

# Add conditional installation of svelte-adapter-bun and update config
RUN if ! grep -q "svelte-adapter-bun" package.json; then \
      bun add -D svelte-adapter-bun; \
    fi

# Install dependencies
RUN bun install --ci

# Copy remaining files
COPY --link . .

# Update svelte.config.js to use Bun adapter
RUN if grep -q "@sveltejs/adapter-" svelte.config.js; then \
      sed -i 's/@sveltejs\/adapter-[a-zA-Z0-9-]\+/svelte-adapter-bun/g' svelte.config.js; \
    fi

# Build the application
RUN bun --bun run vite build

# Production stage
FROM oven/bun:${BUN_VERSION}

WORKDIR /app
COPY --chown=bun:bun --from=builder /app /app

# Create healthcheck script inline
RUN echo 'const check = async () => {\
  try {\
    const response = await fetch(`http://127.0.0.1:${process.env.PORT}/`, {\
      method: "HEAD"\
    });\
    process.exit(response.ok ? 0 : 1);\
  } catch (err) {\
    process.exit(1);\
  }\
};\
check();' > /app/healthcheck.js

ENV PORT=3000
ENV PROTOCOL_HEADER=x-forwarded-proto
ENV HOST_HEADER=x-forwarded-host
EXPOSE 3000/tcp
USER bun

HEALTHCHECK --interval=10s --timeout=3s --start-period=2s --retries=3 \
    CMD bun run /app/healthcheck.js

CMD ["bun", "--bun", "/app/build/index.js"]