# Flux App Delivery Hands-on

Tasks

- Setup Apps Repository
- Create a dedicated GitLab repository for the apps
- Onboard the apps repository in the main Flux repository
- Flux Kustomization
- Add the podinfo deployment manifests to the repository
- Create kustomize overlays for configuring podinfo on dev and prod environments
- Deploy podinfo from the apps repository on the dev cluster
- Run various failure scenarios for the podinfo deployment
- Debugging and troubleshooting the podinfo deployment
- Flux HelmRelease
- Define the podinfo-frontend deployment with OCIRepository and HelmRelease manifests
- Setup different values for the dev and prod environments with kustomize overlays
- Deploy podinfo-frontend from the apps repository on the dev cluster
- Run various scenarios for upgrading, testing and uninstalling
- Debugging and troubleshooting the HelmRelease deployment

## Create Apps Repository

Create a private GitLab repository named `flux-workshop-apps` and clone it locally:

git clone https://gitlab.com/$GITLAB_USER/flux-workshop-apps.git
cd flux-workshop-apps

## Setup podinfo-backend for Flux Kustomization delivery

Switch to the `flux-workshop-apps` repository and follow the steps below.

### Create kustomize overlays

Create the `podinfo-backend` app structure:

mkdir -p apps/podinfo-backend/base apps/podinfo-backend/dev apps/podinfo-backend/prod

Generate the `podinfo-backend` app base structure:

flux pull artifact oci://ghcr.io/stefanprodan/manifests/podinfo:latest \
--output ./apps/podinfo-backend/base/

Create the dev and prod overlays:

tee apps/podinfo-backend/dev/kustomization.yaml apps/podinfo-backend/prod/kustomization.yaml <<'EOF'
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
nameSuffix: -backend
resources:
- ../base
EOF

Running `kustomize build` on any overlay should output the same manifests:

kustomize build apps/podinfo-backend/dev
kustomize build apps/podinfo-backend/prod

Commit the changes to the `flux-workshop-apps` repository:

git add apps
git commit -m "Add podinfo-backend"
git push origin main

## Onboard podinfo-backend

Switch to the `flux-workshop` repository and follow the steps below.

To onboard the apps from the `flux-workshop-apps` repository, create a directory named `apps` in the repo root:

mkdir -p apps

Create a file `apps/namespace.yaml` that defines the Kubernetes namespace for the apps:

apiVersion: v1
kind: Namespace
metadata:
  name: apps

Create the Flux GitRepository manifests for onboarding the `flux-workshop-apps` repository:

flux -n apps create source git apps \
--url=https://gitlab.com/$GITLAB_USER/flux-workshop-apps.git \
--branch=main \
--secret-ref=apps-git-auth \
--export > apps/source.yaml

Create a file `apps/podinfo-backend.yaml` that defines the Flux Kustomization for deploying the app:

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: podinfo-backend
  namespace: apps
spec:
  targetNamespace: apps
  interval: 10m
  retryInterval: 5m
  timeout: 2m
  wait: true
  prune: true
  sourceRef:
    kind: GitRepository
    name: apps
  path: "./apps/podinfo-backend/${CLUSTER_ENV}"
  commonMetadata:
    annotations:
      cluster/name: "${CLUSTER_NAME}"
      cluster/region: "${CLUSTER_REGION}"

Note that the cluster variables are substituted by Flux at runtime from the `cluster-info` ConfigMap.

Create `clusters/dev-cluster/apps.yaml` that defines the Flux Kustomization which reconciles the `apps` directory:

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: apps
  namespace: flux-system
spec:
  interval: 10m
  retryInterval: 5m
  prune: true
  sourceRef:
    kind: GitRepository
    name: flux-system
  path: "./apps"
  postBuild:
    substituteFrom:
      - kind: ConfigMap
        name: cluster-info

Commit the changes to the `flux-workshop` repository:

git add -A
git commit -m "Onboard apps repository"
git push origin main

Wait for the `apps` namespace to be created and then create the `apps-git-auth` secret:

flux -n apps create secret git apps-git-auth \
--url=https://gitlab.com/$GITLAB_USER/flux-workshop-apps.git \
--username=flux \
--password=$GITLAB_TOKEN

Verify that the `flux-workshop-apps` repository is synced:

flux -n apps get all

## Setup podinfo-frontend for Flux HelmRelease delivery

Switch to the `flux-workshop-apps` repository and follow the steps below.

### Create the base overlay for podinfo-frontend

Create the `podinfo-frontend` base dir:

mkdir -p apps/podinfo-frontend/base apps/podinfo-frontend/dev apps/podinfo-frontend/prod

Create an OCIRepository manifest in `podinfo-frontend/base/source.yaml`:

apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: podinfo-frontend
spec:
  interval: 10m
  layerSelector:
    mediaType: "application/vnd.cncf.helm.chart.content.v1.tar+gzip"
    operation: copy
  url: oci://ghcr.io/stefanprodan/charts/podinfo
  ref:
    semver: "*"

Create a HelmRelease manifest in `podinfo-frontend/base/release.yaml`:

apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
metadata:
  name: podinfo-frontend
spec:
  interval: 10m
  releaseName: podinfo-frontend
  driftDetection:
    mode: enabled
  chartRef:
    kind: OCIRepository
    name: podinfo-frontend
  valuesFrom:
    - kind: ConfigMap
      name: podinfo-values

Create a `kustomization.yaml` in `podinfo-frontend/base`:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- source.yaml
- release.yaml

### Create the dev and prod overlays for podinfo-frontend

Create the `podinfo-frontend` overlays:

mkdir -p apps/podinfo-frontend/dev apps/podinfo-frontend/prod

Create a `values.yaml` in `podinfo-frontend/dev`:

replicaCount: 2
backend: http://podinfo-backend:9898/echo

Create a `kustomizeconfig.yaml` in `podinfo-frontend/dev`:

nameReference:
- kind: ConfigMap
  version: v1
  fieldSpecs:
  - path: spec/valuesFrom/name
    kind: HelmRelease
- kind: Secret
  version: v1
  fieldSpecs:
  - path: spec/valuesFrom/name
    kind: HelmRelease

Create a `kustomization.yaml` in `podinfo-frontend/dev`:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - ../base
configMapGenerator:
  - name: podinfo-values
    files:
      - values.yaml=values.yaml
configurations:
  - kustomizeconfig.yaml
patches:
  - patch: |
      - op: replace
        path: /spec/ref/semver
        value: "6.7.0"
    target:
      kind: OCIRepository

Copy dev overlay to prod:

cp -r apps/podinfo-frontend/dev/. apps/podinfo-frontend/prod

Commit the changes to the `flux-workshop-apps` repository:

git add -A
git commit -m "Add podinfo-frontend helm release"
git push origin main

## Onboard podinfo-frontend

Switch to the `flux-workshop` repository and follow the steps below.

Create the `podinfo-frontend` Flux Kustomization in `apps/podinfo-frontend.yaml`:

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: podinfo-frontend
  namespace: apps
spec:
  targetNamespace: apps
  interval: 10m
  retryInterval: 5m
  timeout: 5m
  wait: true
  prune: true
  sourceRef:
    kind: GitRepository
    name: apps
  path: "./apps/podinfo-frontend/${CLUSTER_ENV}"
  commonMetadata:
    annotations:
      cluster/name: "${CLUSTER_NAME}"
      cluster/region: "${CLUSTER_REGION}"

Commit the changes to the `flux-workshop` repository:

git add -A
git commit -m "Onboard podinfo-frontend"
git push origin main

Wait for the `podinfo-frontend` HelmRelease to be deployed:

flux get all -A

# Flux App Delivery Hands-on

Tasks

- Setup Apps Repository
- Create a dedicated GitLab repository for the apps
- Onboard the apps repository in the main Flux repository
- Flux Kustomization
- Add the podinfo deployment manifests to the repository
- Create kustomize overlays for configuring podinfo on dev and prod environments
- Deploy podinfo from the apps repository on the dev cluster
- Run various failure scenarios for the podinfo deployment
- Debugging and troubleshooting the podinfo deployment
- Flux HelmRelease
- Define the podinfo-frontend deployment with OCIRepository and HelmRelease manifests
- Setup different values for the dev and prod environments with kustomize overlays
- Deploy podinfo-frontend from the apps repository on the dev cluster
- Run various scenarios for upgrading, testing and uninstalling
- Debugging and troubleshooting the HelmRelease deployment

## Create Apps Repository

Create a private GitLab repository named `flux-workshop-apps` and clone it locally:

git clone https://gitlab.com/$GITLAB_USER/flux-workshop-apps.git
cd flux-workshop-apps

## Setup podinfo-backend for Flux Kustomization delivery

Switch to the `flux-workshop-apps` repository and follow the steps below.

### Create kustomize overlays

Create the `podinfo-backend` app structure:

mkdir -p apps/podinfo-backend/base apps/podinfo-backend/dev apps/podinfo-backend/prod

Generate the `podinfo-backend` app base structure:

flux pull artifact oci://ghcr.io/stefanprodan/manifests/podinfo:latest \
--output ./apps/podinfo-backend/base/

Create the dev and prod overlays:

tee apps/podinfo-backend/dev/kustomization.yaml apps/podinfo-backend/prod/kustomization.yaml <<'EOF'
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
nameSuffix: -backend
resources:
- ../base
EOF

Running `kustomize build` on any overlay should output the same manifests:

kustomize build apps/podinfo-backend/dev
kustomize build apps/podinfo-backend/prod

Commit the changes to the `flux-workshop-apps` repository:

git add apps
git commit -m "Add podinfo-backend"
git push origin main

## Onboard podinfo-backend

Switch to the `flux-workshop` repository and follow the steps below.

To onboard the apps from the `flux-workshop-apps` repository, create a directory named `apps` in the repo root:

mkdir -p apps

Create a file `apps/namespace.yaml` that defines the Kubernetes namespace for the apps:

apiVersion: v1
kind: Namespace
metadata:
  name: apps

Create the Flux GitRepository manifests for onboarding the `flux-workshop-apps` repository:

flux -n apps create source git apps \
--url=https://gitlab.com/$GITLAB_USER/flux-workshop-apps.git \
--branch=main \
--secret-ref=apps-git-auth \
--export > apps/source.yaml

Create a file `apps/podinfo-backend.yaml` that defines the Flux Kustomization for deploying the app:

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: podinfo-backend
  namespace: apps
spec:
  targetNamespace: apps
  interval: 10m
  retryInterval: 5m
  timeout: 2m
  wait: true
  prune: true
  sourceRef:
    kind: GitRepository
    name: apps
  path: "./apps/podinfo-backend/${CLUSTER_ENV}"
  commonMetadata:
    annotations:
      cluster/name: "${CLUSTER_NAME}"
      cluster/region: "${CLUSTER_REGION}"

Note that the cluster variables are substituted by Flux at runtime from the `cluster-info` ConfigMap.

Create `clusters/dev-cluster/apps.yaml` that defines the Flux Kustomization which reconciles the `apps` directory:

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: apps
  namespace: flux-system
spec:
  interval: 10m
  retryInterval: 5m
  prune: true
  sourceRef:
    kind: GitRepository
    name: flux-system
  path: "./apps"
  postBuild:
    substituteFrom:
      - kind: ConfigMap
        name: cluster-info

Commit the changes to the `flux-workshop` repository:

git add -A
git commit -m "Onboard apps repository"
git push origin main

Wait for the `apps` namespace to be created and then create the `apps-git-auth` secret:

flux -n apps create secret git apps-git-auth \
--url=https://gitlab.com/$GITLAB_USER/flux-workshop-apps.git \
--username=flux \
--password=$GITLAB_TOKEN

Verify that the `flux-workshop-apps` repository is synced:

flux -n apps get all

## Setup podinfo-frontend for Flux HelmRelease delivery

Switch to the `flux-workshop-apps` repository and follow the steps below.

### Create the base overlay for podinfo-frontend

Create the `podinfo-frontend` base dir:

mkdir -p apps/podinfo-frontend/base apps/podinfo-frontend/dev apps/podinfo-frontend/prod

Create an OCIRepository manifest in `podinfo-frontend/base/source.yaml`:

apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: podinfo-frontend
spec:
  interval: 10m
  layerSelector:
    mediaType: "application/vnd.cncf.helm.chart.content.v1.tar+gzip"
    operation: copy
  url: oci://ghcr.io/stefanprodan/charts/podinfo
  ref:
    semver: "*"

Create a HelmRelease manifest in `podinfo-frontend/base/release.yaml`:

apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
metadata:
  name: podinfo-frontend
spec:
  interval: 10m
  releaseName: podinfo-frontend
  driftDetection:
    mode: enabled
  chartRef:
    kind: OCIRepository
    name: podinfo-frontend
  valuesFrom:
    - kind: ConfigMap
      name: podinfo-values

Create a `kustomization.yaml` in `podinfo-frontend/base`:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- source.yaml
- release.yaml

### Create the dev and prod overlays for podinfo-frontend

Create the `podinfo-frontend` overlays:

mkdir -p apps/podinfo-frontend/dev apps/podinfo-frontend/prod

Create a `values.yaml` in `podinfo-frontend/dev`:

replicaCount: 2
backend: http://podinfo-backend:9898/echo

Create a `kustomizeconfig.yaml` in `podinfo-frontend/dev`:

nameReference:
- kind: ConfigMap
  version: v1
  fieldSpecs:
  - path: spec/valuesFrom/name
    kind: HelmRelease
- kind: Secret
  version: v1
  fieldSpecs:
  - path: spec/valuesFrom/name
    kind: HelmRelease

Create a `kustomization.yaml` in `podinfo-frontend/dev`:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - ../base
configMapGenerator:
  - name: podinfo-values
    files:
      - values.yaml=values.yaml
configurations:
  - kustomizeconfig.yaml
patches:
  - patch: |
      - op: replace
        path: /spec/ref/semver
        value: "6.7.0"
    target:
      kind: OCIRepository

Copy dev overlay to prod:

cp -r apps/podinfo-frontend/dev/. apps/podinfo-frontend/prod

Commit the changes to the `flux-workshop-apps` repository:

git add -A
git commit -m "Add podinfo-frontend helm release"
git push origin main

## Onboard podinfo-frontend

Switch to the `flux-workshop` repository and follow the steps below.

Create the `podinfo-frontend` Flux Kustomization in `apps/podinfo-frontend.yaml`:

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: podinfo-frontend
  namespace: apps
spec:
  targetNamespace: apps
  interval: 10m
  retryInterval: 5m
  timeout: 5m
  wait: true
  prune: true
  sourceRef:
    kind: GitRepository
    name: apps
  path: "./apps/podinfo-frontend/${CLUSTER_ENV}"
  commonMetadata:
    annotations:
      cluster/name: "${CLUSTER_NAME}"
      cluster/region: "${CLUSTER_REGION}"

Commit the changes to the `flux-workshop` repository:

git add -A
git commit -m "Onboard podinfo-frontend"
git push origin main

Wait for the `podinfo-frontend` HelmRelease to be deployed:

flux get all -A