ADR-0039: Deploy Sourced Component Architecture

Status: Accepted
Date: 2026-06-12
Author: @johalputt

Context

The VayuPress deploy script embeds the full Go main.go source as a heredoc. This creates a single-file deploy artifact: download the script, run it, get a working server. However, as the deploy script grows (now ~4,000 lines), it becomes difficult to read and maintain if all components are interleaved.

Decision

1. The deploy script is organized into sourced component sections with clear delimiters: ## === COMPONENT: <name> ===.
2. Components are: go-source, nginx-config, systemd-units, cron-jobs, smoke-tests.
3. Each component section is self-contained: it defines its own variables, creates its own files, and handles its own error conditions.
4. The main script body calls component functions in order, with set -euo pipefail active throughout.
5. The --dry-run flag causes each component to print what it would do without making filesystem changes.

Rationale

Sourced components with clear section boundaries allow a maintainer to find and modify the nginx config without reading the Go source, or update systemd units without touching cron jobs. The --dry-run flag makes the script safe to audit on production servers.

Consequences

• Positive: Each component is independently readable and testable.
• Positive: --dry-run enables safe pre-deployment validation.
• Positive: shellcheck can verify each section independently.
• Negative: The script remains a single file — very long. Alternative: split into multiple files. This was rejected because it complicates the single-download deploy UX.