Auto-Deploying Manifests

Any YAML placed in the manifests directory is applied automatically by k3s.

k3s watches a special folder and applies whatever YAML it finds there. This is the auto-deploying manifests feature, powered by the internal rancher/helm-controller and add-on system.

The magic folder

/var/lib/rancher/k3s/server/manifests/

Drop a manifest in that directory and k3s applies it automatically, even across reboots. Remove the file and k3s tidies up the resources it created. This is great for baking apps into a machine image or provisioning edge devices.

Example

Example · bash
# Place a manifest and k3s deploys it for you
sudo cp web-app.yaml \
  /var/lib/rancher/k3s/server/manifests/

# Watch it appear
kubectl get pods -w

# Deleting the file removes the resources
sudo rm /var/lib/rancher/k3s/server/manifests/web-app.yaml

When to use it

  • An operator places a namespace YAML file in /var/lib/rancher/k3s/server/manifests/ so k3s creates the namespace automatically on every boot.
  • A team drops HelmChart CRD manifests into the auto-deploy directory to ensure monitoring tools are installed before any workload runs.
  • A GitOps pipeline syncs curated manifests to the k3s manifests directory on the server, letting k3s handle the apply without an external controller.

More examples

Place a manifest for auto-deploy

Writes a Namespace manifest to the k3s manifests directory; k3s detects the file and applies it within seconds.

Example · bash
cat > /var/lib/rancher/k3s/server/manifests/my-namespace.yaml << 'EOF'
apiVersion: v1
kind: Namespace
metadata:
  name: production
EOF
# k3s applies it immediately without a kubectl apply

Add a HelmChart to manifests

Copies a HelmChart CRD manifest into the auto-deploy directory and verifies k3s installed the chart.

Example · bash
cp my-helmchart.yaml /var/lib/rancher/k3s/server/manifests/
kubectl get helmchart -n kube-system
kubectl get pods -n monitoring

List auto-deployed resources

Lists the files in the manifests directory and shows all kube-system resources to confirm auto-deployment ran.

Example · bash
ls /var/lib/rancher/k3s/server/manifests/
kubectl get all -n kube-system | grep -v '^$'

Related

k3s helmk3s config file

Discussion

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