🧩 universal-backup-operator

A Kubernetes Operator written in Go that provides a declarative way to define and run backups to any storage destination — S3, GCS, Azure, Git repositories, NFS, or local PVCs.

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🚀 Overview

The universal-backup-operator introduces a custom resource called BackupJob that allows cluster users to declare:

• what to back up (target)
• how to back up (strategy)
• where to store it (destination)

The operator automatically schedules and executes Kubernetes Jobs or CronJobs to perform backups based on this definition.

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📦 Example CRD Usage

apiVersion: backup.javy.dev/v1
kind: BackupJob
metadata:
  name: postgres-daily-backup
spec:
  target:
    kind: StatefulSet
    name: postgres
    namespace: default
    path: /var/lib/postgresql/data
  destination:
    type: s3
    uri: s3://my-bucket/backups/postgres
    secretRef: s3-credentials
  strategy:
    type: dump
    command: "pg_dumpall > /backup/dump.sql"
  schedule: "0 2 * * *"

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🌐 Supported Destinations (planned)

Type	Description	Example
s3	AWS S3, MinIO, Wasabi	s3://mybucket/backups
gcs	Google Cloud Storage	gs://mybucket/backups
azure	Azure Blob Storage	az://container/path
git	Git-based backup repo	git@github.com:user/backups.git
nfs	On-prem or local NFS mount	nfs://server/path
local	PersistentVolumeClaim	pvc://my-backups
custom	Run arbitrary backup command	-

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🧱 Architecture

• Custom Resource → BackupJob CRD defines backup specifications
• Controller → watches for CR changes, creates Job/CronJob
• Backup Runner → small container images implementing backup logic for each destination type
• Status updates → operator tracks BackupJob.status (phase, lastRun, message)

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🧰 Prerequisites

Before development or deployment:

• Go 1.22.5+
• kubectl
• Docker
• kind or another Kubernetes cluster
• kubebuilder

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⚙️ Development Setup

1️⃣ Clone the Repo

git clone https://github.com/javydevx/universal-backup-operator.git
cd universal-backup-operator

2️⃣ Scaffold Project Using Kubebuilder (if not done already)

kubebuilder init --domain javy.dev --repo github.com/javydevx/universal-backup-operator
kubebuilder create api --group backup --version v1 --kind BackupJob --resource --controller

This creates the following structure:

api/v1/backupjob_types.go           # CRD schema
controllers/backupjob_controller.go # Reconcile logic
config/                             # CRDs, RBAC, manager manifests
main.go                             # entrypoint

3️⃣ Generate Manifests

make manifests

4️⃣ Run the Operator Locally

make run

5️⃣ Apply CRD and Create a Sample BackupJob

kubectl apply -f config/crd/bases/backup.javy.dev_backupjobs.yaml
kubectl apply -f config/samples/backup_v1_backupjob.yaml

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🧩 Roadmap

Milestone	Status	Description
Scaffold Operator with Kubebuilder	✅	Basic setup
Implement S3 backups	🚧	MVP target
Add Git backup support	⏳	Push to Git repos
Add GCS & Azure destinations	⏳	Cloud expansion
Support PVC/NFS local backups	⏳	On-prem support
Add Cron scheduling	⏳	Recurring backups
Add status tracking	⏳	Phase, timestamps
Expose /restore endpoint via Aggregated API Server	⏳	API extension feature

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🧑‍💻 Contributing

Contributions are welcome! This project is open-source and educational, intended to help developers learn Kubernetes Operator patterns and API extension techniques.

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📘 References

Resource	Link	Notes
🧱 Kubebuilder Book	https://book.kubebuilder.io/	Official guide for building operators
⚙️ Operator SDK	https://sdk.operatorframework.io/docs/	Alternative framework
📘 controller-runtime	https://github.com/kubernetes-sigs/controller-runtime	Core library
🧩 CronJob tutorial	https://book.kubebuilder.io/cronjob-tutorial/cronjob-tutorial.html	Good starting example
🧰 Kubernetes Code Generator	https://github.com/kubernetes/code-generator	Underlying codegen tool

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📄 License

This project is licensed under the Apache License 2.0. See the LICENSE file for details.

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✨ Author’s Note

The goal of this project is to demonstrate:

• Building a Kubernetes Operator in Go

• Designing flexible CRDs

• Extending the Kubernetes API in two ways:

  1. CustomResourceDefinitions (CRDs)
  2. Aggregated API Servers

By the end, you’ll have a working backup operator that can evolve into a production-grade system.

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💡 Next Step: Run kubebuilder init (if not already done) and scaffold the project, then define the CRD (BackupJob) fields and reconcile logic next.