openova/platform/flux/README.md

Flux

GitOps delivery engine. Per-host-cluster infrastructure (see docs/PLATFORM-TECH-STACK.md §3.2). Catalyst runs one Flux instance per vcluster (lightweight: source + kustomize + helm controllers) plus a host-level Flux on each host cluster for the Catalyst control plane itself. Each per-vcluster Flux pulls from the single per-Sovereign Gitea instance (see docs/ARCHITECTURE.md §4).

Status: Accepted | Updated: 2026-04-27

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Overview

Flux provides GitOps-based continuous delivery with Gitea as the internal Git provider and External Secrets Operator for secrets management.

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Architecture

flowchart TB
    subgraph Gitea["Gitea (Internal Git)"]
        Components[Component Repos]
        Organization[Organization Repos]
    end

    subgraph K8s["Kubernetes Cluster"]
        subgraph Flux["Flux Controllers"]
            Source[source-controller]
            Kustomize[kustomize-controller]
            Helm[helm-controller]
            Notify[notification-controller]
        end

        subgraph ESO["Secrets"]
            ESOp[External Secrets Operator]
            PS[PushSecrets]
        end

        Resources[K8s Resources]
    end

    subgraph External["External"]
        OpenBao[OpenBao]
    end

    Components --> Source
    Organization --> Source
    Source --> Kustomize
    Source --> Helm
    Kustomize --> Resources
    Helm --> Resources
    Notify --> Gitea
    ESOp --> OpenBao
    ESOp --> Resources

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Why Flux

Factor	Flux	ArgoCD
Memory overhead	~200MB	~500-800MB
Architecture	Kubernetes-native CRDs	Separate UI/API
Secrets	Via ESO (PushSecrets)	Via ESO (PushSecrets)
CLI workflow	Excellent	UI-focused

Key Decision Factors:

• Lower resource overhead
• CLI-focused fits single-developer workflow
• Kubernetes-native CRDs
• Works well with External Secrets Operator
• Integrates seamlessly with Gitea

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Components

Controller	Memory	Purpose
source-controller	64MB	Git/Helm repo sync
kustomize-controller	64MB	Kustomization apply
helm-controller	64MB	HelmRelease management
notification-controller	32MB	Alerts

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Repository Structure

flux/
├── clusters/
│   └── <region>/
│       ├── flux-system/       # Flux controllers
│       ├── network/           # cilium, stunner, k8gb
│       ├── security/          # kyverno, external-secrets, cert-manager
│       ├── database/          # cnpg, ferretdb, valkey
│       ├── middleware/        # strimzi
│       ├── storage/           # seaweedfs, velero
│       ├── observability/     # grafana (LGTM stack)
│       ├── autoscaling/       # keda
│       ├── workplace/         # stalwart
│       └── organizations/     # per-Organization Application deployments

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Categories

Category	Components	Purpose
network	cilium, stunner, k8gb	CNI + Service Mesh, TURN, GSLB
security	kyverno, external-secrets, cert-manager	Policy, secrets, TLS
database	cnpg, ferretdb, valkey	Database operators
middleware	strimzi	Apache Kafka streaming
storage	seaweedfs, velero	Object storage, backup
observability	grafana	LGTM stack
autoscaling	keda	Event-driven scaling
workplace	stalwart	Email server
organizations	<org>	Per-Organization Application deployments

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Configuration

GitRepository for Gitea

apiVersion: source.toolkit.fluxcd.io/v1
kind: GitRepository
metadata:
  name: <component>
  namespace: flux-system
spec:
  interval: 5m
  url: https://gitea.<location-code>.<sovereign-domain>/<org>/<component>.git
  ref:
    branch: main
  secretRef:
    name: gitea-token

Kustomization

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: <component>
  namespace: flux-system
spec:
  interval: 10m
  targetNamespace: <namespace>
  sourceRef:
    kind: GitRepository
    name: <component>
  path: ./deploy/prod
  prune: true
  wait: true
  healthChecks:
    - apiVersion: apps/v1
      kind: Deployment
      name: <component>
      namespace: <namespace>

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Multi-Region GitOps

Catalyst runs one Gitea per Sovereign on the management cluster (see docs/PLATFORM-TECH-STACK.md §2.3). Each workload region's Flux pulls from that single Gitea over the cross-region network. Per-region HA comes from Gitea's intra-cluster replicas + CNPG-backed metadata, not cross-region bidirectional mirror.

flowchart TB
    subgraph Mgt["Management cluster (per Sovereign)"]
        Gitea[Gitea — single instance, K8s-replicated for HA]
    end

    subgraph Region1["Workload region 1 (rtz)"]
        Flux1[Per-vcluster Flux]
        K8s1[Org vcluster workloads]
    end

    subgraph Region2["Workload region 2 (rtz)"]
        Flux2[Per-vcluster Flux]
        K8s2[Org vcluster workloads]
    end

    Gitea --> Flux1
    Gitea --> Flux2
    Flux1 --> K8s1
    Flux2 --> K8s2

• One Gitea per Sovereign (on the mgt cluster). HA via intra-cluster replicas, not cross-region mirror.
• Each vcluster runs its own lightweight Flux that pulls from this single Gitea.
• Per-region configuration is encoded in the Environment's manifests via Kustomize overlays / Placement metadata.

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Secrets Management

Flux uses External Secrets Operator (ESO) with PushSecrets pattern:

• No SOPS: SOPS has been eliminated from the architecture
• PushSecrets: 100% PushSecrets pattern for multi-region
• K8s Secrets as source of truth: Apps read from K8s Secrets only

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Release Management

Release Flow

Feature Branch → PR → main → Flux Sync → Staging → Promote → Production
                                            ↓
                                      Canary Analysis (Flagger)
                                            ↓
                                      Auto-Rollback (on failure)

Environment Strategy

Environment	Sync Interval
Staging	1m
Production	10m

Rollback Strategy

Trigger	Action
Flagger metric failure	Auto-rollback
Manual intervention	Git revert + sync
Emergency	kubectl rollout undo

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Bootstrap

# Initial cluster bootstrap (Gitea)
flux bootstrap git \
  --url=https://gitea.<location-code>.<sovereign-domain>/openova/flux \
  --branch=main \
  --path=clusters/<region> \
  --token-auth

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Key Commands

# Status overview
flux get all

# Force reconciliation
flux reconcile kustomization organizations

# View logs
flux logs --all-namespaces

# Suspend (manual gate)
flux suspend kustomization <org>-prod

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Sync Intervals

Resource	Interval
GitRepository	1 minute
Kustomization	10 minutes
HelmRelease	10 minutes

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Gitea Actions Integration

Gitea Actions can trigger Flux reconciliation:

# .gitea/workflows/notify-flux.yaml
name: Notify Flux
on:
  push:
    branches: [main]

jobs:
  notify:
    runs-on: ubuntu-latest
    steps:
      - name: Trigger Flux reconciliation
        run: |
          curl -X POST \
            -H "Authorization: Bearer ${{ secrets.FLUX_WEBHOOK_TOKEN }}" \
            https://flux-webhook.<location-code>.<sovereign-domain>/hook/...          

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Part of OpenOva