jakman85andClaude Opus 4.8
e8c555cfeb
Greenfield spec set for a GitOps-driven PaaS+IaaS home platform: vision & requirements (R-* IDs), architecture, 14 domain specs, 11 ADRs, roadmap (phases + workstreams), and AI-agent coordination (roles, protocol, definition-of-done, task board). Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
36 lines
1.9 KiB
Markdown
36 lines
1.9 KiB
Markdown
# ADR-0004 — GitOps engine: Flux CD
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- Status: Accepted
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- Date: 2026-08-15
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- Serves: R-GITOPS-01, R-GITOPS-02, R-GITOPS-03, R-UPD-02, R-SEC-01, R-ENV-02
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- Supersedes: —
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## Context
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All desired state must be reconciled from git (pull-based), with drift correction, environment
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overlays (dev↔prod), encrypted secrets, and — critically — **hands-off image updates** driven by
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declared policy (R-UPD-02). The GitOps engine choice is tightly coupled to the update mechanism and
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the secrets model.
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## Decision
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Use **Flux CD** for reconciliation, chosen decisively because it *natively* provides the two
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capabilities that matter most for this platform's hard requirements:
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- **image-update-automation** (image-reflector + image-automation controllers) for policy-driven,
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no-human image updates (R-UPD-02, ADR-0009).
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- **native SOPS decryption** for encrypted-in-git secrets (R-SEC-01, ADR-0007).
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Flux Kustomize/Helm controllers handle overlays (dev↔prod, R-ENV-02) and chart-based platform
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components.
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## Alternatives considered
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- **Argo CD** — excellent UI and ApplicationSets; but image auto-update (Argo Image Updater) and
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secret decryption are add-ons rather than first-class, and the platform gets its UI from the C2
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composition ([12](../docs/12-command-center-ui.md)) rather than from the GitOps tool. Reasonable
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alternative; Flux wins on native image-automation + SOPS fit.
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- **Rancher Fleet / Kustomize-only + CI push** — weaker fit for the automated-update and drift
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requirements.
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## Consequences
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- Native, first-class path to R-UPD-02 (no bolt-on for automated updates) and R-SEC-01 (SOPS).
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- GitOps status/health is surfaced in the C2 UI via Headlamp/Flux views ([12](../docs/12-command-center-ui.md)),
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not via a bundled GitOps GUI.
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- Reconciliation failures/drift are alerting conditions (R-OBS-04).
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- If a rich built-in GitOps GUI later becomes a priority, revisit via superseding ADR (Argo).
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