DEMO Source Controller Git Manifest in Flux Repo

In this guide, you’ll learn how Flux’s Source Controller pulls manifests from a Git repository and how the Kustomize Controller applies them to a Kubernetes cluster, showcasing a GitOps-driven workflow.

Ensure you’ve bootstrapped Flux CD with SSH credentials so the secretRef in your GitRepository can authenticate to GitHub.
See Flux CD installation for details.

1. Define GitRepository and Kustomization

Create a GitRepository to tell Flux where to fetch your manifests, then reference it in a Kustomization:

apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: GitRepository
metadata:
  name: flux-system
  namespace: flux-system
spec:
  interval: 10s
  url: ssh://git@github.com/sidd-harth-2/block-buster
  ref:
    branch: main
  secretRef:
    name: flux-system
---
apiVersion: kustomize.toolkit.fluxcd.io/v1beta2
kind: Kustomization
metadata:
  name: flux-system
  namespace: flux-system
spec:
  interval: 10s
  path: ./flux-clusters/dev-cluster
  prune: true
  sourceRef:
    kind: GitRepository
    name: flux-system

Key fields explained:

interval: reconciliation frequency
url/ref: Git source and branch
secretRef: SSH key for cloning
path: directory in the repo to apply
prune: deletes resources removed from Git

Flux Controllers Overview

Flux Controller	Resource	Purpose	Example CLI
Source Controller	GitRepository	Fetches manifests from Git	`flux get sources git`
Kustomize Controller	Kustomization	Applies overlays and syncs resources	`flux get kustomizations`

2. Verify Flux Sources and Kustomizations

Confirm that Flux has registered your sources and kustomizations:

# List all registered sources
flux get sources

# Filter for Git sources
flux get sources git
# NAME         REVISION                READY   MESSAGE
# flux-system  main@sha1:edf2288f      True    stored artifact for revision 'main@sha1:edf2288f'

# List Kustomizations
flux get kustomizations
# NAME         REVISION                READY   MESSAGE
# flux-system  main@sha1:edf2288f      True    Applied revision: main@sha1:edf2288f

3. Import and Clone the Demo Application

We’ll use a repository named bb-app-source containing both app code and Kubernetes manifests.

Import into your GitHub account

The image shows a GitHub page for importing a project, with fields for the old repository's clone URL and new repository details, including options for public or private visibility. A "Begin import" button is highlighted.

Clone locally and switch to the demo branch

git clone https://github.com/your-account/bb-app-source
cd bb-app-source
git checkout 1-demo

The image shows a GitHub page indicating that a new repository import is complete, with a user menu open on the right side.

4. Examine Application Source and Manifests

src/: PHP app reporting its Pod and namespace.
manifests/1-demo/: Contains three YAML definitions:
- deployment.yml
- namespace.yml
- service.yml

The image shows a GitHub repository page with a directory listing for "1-demo" containing three YAML files: deployment.yml, namespace.yml, and service.yml.

Here’s the Deployment snippet (manifests/1-demo/deployment.yml):

apiVersion: apps/v1
kind: Deployment
metadata:
  name: block-buster
  namespace: 1-demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: block-buster
      version: "7.1.0"
      env: dev
  template:
    metadata:
      labels:
        app: block-buster
        version: "7.1.0"
        env: dev
    spec:
      containers:
        - name: app
          image: siddharth67/block-buster-dev:7.1.0
          imagePullPolicy: Always
          resources:
            requests:
              memory: "10Mi"
              cpu: "10m"
            limits:
              memory: "20Mi"
              cpu: "50m"

5. Add Manifests to Your Flux Cluster Repo

Copy the demo manifests into your Flux cluster repository under flux-clusters/dev-cluster/1-demo:

cp manifests/1-demo/*.yml \
   ../block-buster/flux-clusters/dev-cluster/1-demo/
cd ../block-buster/flux-clusters/dev-cluster/
git add 1-demo/*.yml
git commit -m "Add 1-demo manifests"
git push

Flux will detect these new files and begin applying them automatically.

6. Verify the GitOps Deployment

Check Kubernetes namespaces

kubectl get ns
# NAME         STATUS   AGE
# 1-demo       Active   30s
# default      Active   49m
# flux-system  Active   42m

Confirm Flux has the latest revision

flux get sources git
flux get kustomizations

7. Inspect the Source Controller Cache

Dive into the Source Controller pod to view the cached repository archive:

kubectl -n flux-system exec -it deploy/source-controller -- sh
cd data/gitrepository/flux-system/flux-system
ls -ltr
# latest.tar.gz -> ...cf1664a0b9...tar.gz
tar -tf latest.tar.gz
# flux-clusters/
# flux-clusters/dev-cluster/1-demo/deployment.yaml
# flux-clusters/dev-cluster/1-demo/namespace.yaml
# flux-clusters/dev-cluster/1-demo/service.yaml
exit

8. Access the Deployed Application

List resources in the demo namespace

kubectl -n 1-demo get all
# pod/block-buster-...      1/1   Running   0   2m
# service/block-buster-svc  NodePort  10.110.102.187  <none>  80:30001/TCP 2m

Open the game in your browser
http://localhost:30001

The image shows a web-based game interface called "Block Buster" with a notification indicating "Level 1 Completed." It includes game details like pod name, IP, namespace, and app version, with a simple game layout featuring a paddle and ball.

This PHP-based game displays live pod metadata, demonstrating a full GitOps flow with Flux CD.

GitOps Overview

Flux Overview

Source and Kustomize Controller

Helm Controller and OCI Registry

Image Automation Controller

Secret Management & Sign Verification

Notification Controller

Monitoring & User Interface

DEMO Source Controller Git Manifest in Flux Repo

1. Define GitRepository and Kustomization

Flux Controllers Overview

2. Verify Flux Sources and Kustomizations

3. Import and Clone the Demo Application

4. Examine Application Source and Manifests

5. Add Manifests to Your Flux Cluster Repo

6. Verify the GitOps Deployment

7. Inspect the Source Controller Cache

8. Access the Deployed Application

Links and References

Watch Video

Practice Lab

​1. Define GitRepository and Kustomization

​Flux Controllers Overview

​2. Verify Flux Sources and Kustomizations

​3. Import and Clone the Demo Application

​4. Examine Application Source and Manifests

​5. Add Manifests to Your Flux Cluster Repo

​6. Verify the GitOps Deployment

​7. Inspect the Source Controller Cache

​8. Access the Deployed Application

​Links and References

Watch Video

Practice Lab

1. Define GitRepository and Kustomization

Flux Controllers Overview

2. Verify Flux Sources and Kustomizations

3. Import and Clone the Demo Application

4. Examine Application Source and Manifests

5. Add Manifests to Your Flux Cluster Repo

6. Verify the GitOps Deployment

7. Inspect the Source Controller Cache

8. Access the Deployed Application

Links and References