K3s multi-node install
Big picture​
This tutorial gets you a multi node K3s cluster with Calico in approximately 10 minutes.
Value​
K3s is a lightweight implementation of Kubernetes packaged as a single binary.
The geeky details of what you get:
Policy | IPAM | CNI | Overlay | Routing | Datastore |
---|---|---|---|---|---|
Before you begin​
- Make sure you have a linux host that meets the following requirements
- x86-64 processor
- 1CPU
- 1GB Ram
- 10GB free disk space
- Ubuntu 18.04 (amd64), Ubuntu 20.04 (amd64)
K3s supports ARM processors too, this tutorial was tested against x86-64 processor environment. For more detail please visit this link.
How to​
Initializing control plane instance​
K3s installation script can be modified by environment variables. Here you are providing some extra arguments to disable flannel
, disable k3s default network policy and change the pod ip CIDR.
Full list of arguments can be viewed at this link.
curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC="--flannel-backend=none --disable-network-policy --cluster-cidr=192.168.0.0/16" sh -
If 192.168.0.0/16 is already in use within your network you must select a different pod network CIDR by replacing 192.168.0.0/16 in the above command.
Enable remote access to your K3s instance​
To set up remote access to your cluster first ensure you have installed kubectl
on your system.
If you are not sure how to install kubectl in your OS visit this link.
K3s stores a kubeconfig file in your server at /etc/rancher/k3s/k3s.yaml
, copy all the content of k3s.yaml
from your server into ~/.kube/config
on the system that you like to have remote access to the cluster.
Add extra nodes to K3s cluster​
To add additional nodes to your cluster you need two piece of information.
K3S_URL
which is going to be your main node ip address.K3S_TOKEN
which is stored in/var/lib/rancher/k3s/server/node-token
file in main Node (Step 1). Execute following command in your node instance and join it to the cluster.
Remember to change serverip
and mytoken
.
curl -sfL https://get.k3s.io | K3S_URL=https://serverip:6443 K3S_TOKEN=mytoken sh -
Install Calico​
- Operator
- Manifest
Install the Calico operator and custom resource definitions.
kubectl create -f https://raw.githubusercontent.com/projectcalico/calico/v3.29.0/manifests/tigera-operator.yaml
Due to the large size of the CRD bundle, kubectl apply
might exceed request limits. Instead, use kubectl create
or kubectl replace
.
Install Calico by creating the necessary custom resource. For more information on configuration options available in this manifest, see the installation reference.
kubectl create -f https://raw.githubusercontent.com/projectcalico/calico/v3.29.0/manifests/custom-resources.yaml
Before creating this manifest, read its contents and make sure its settings are correct for your environment. For example, you may need to change the default IP pool CIDR to match your pod network CIDR.
Install Calico by using the following command.
kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.29.0/manifests/calico.yaml
You can also view the YAML in a new tab.
You should see the following output.
configmap/calico-config created
customresourcedefinition.apiextensions.k8s.io/bgpconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/bgppeers.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/blockaffinities.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/clusterinformations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/felixconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/globalnetworkpolicies.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/globalnetworksets.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/hostendpoints.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamblocks.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamconfigs.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamhandles.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ippools.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/kubecontrollersconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/networkpolicies.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/networksets.crd.projectcalico.org created
clusterrole.rbac.authorization.k8s.io/calico-kube-controllers created
clusterrolebinding.rbac.authorization.k8s.io/calico-kube-controllers created
clusterrole.rbac.authorization.k8s.io/calico-node created
clusterrolebinding.rbac.authorization.k8s.io/calico-node created
daemonset.apps/calico-node created
serviceaccount/calico-node created
deployment.apps/calico-kube-controllers created
serviceaccount/calico-kube-controllers created
Check the installation​
- Confirm that all of the pods are running using the following command.
- Operator
- Manifest
NAMESPACE NAME READY STATUS RESTARTS AGE
tigera-operator tigera-operator-c9cf5b94d-gj9qp 1/1 Running 0 107s
calico-system calico-typha-7dcd87597-npqsf 1/1 Running 0 88s
calico-system calico-node-rdwwz 1/1 Running 0 88s
kube-system local-path-provisioner-6d59f47c7-4q8l2 1/1 Running 0 2m14s
kube-system metrics-server-7566d596c8-xf66d 1/1 Running 0 2m14s
kube-system coredns-8655855d6-wfdbm 1/1 Running 0 2m14s
calico-system calico-kube-controllers-89df8c6f8-7hxc5 1/1 Running 0 87s
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-node-9hn9z 1/1 Running 0 23m
kube-system local-path-provisioner-6d59f47c7-drznc 1/1 Running 0 38m
kube-system calico-kube-controllers-789f6df884-928lt 1/1 Running 0 23m
kube-system metrics-server-7566d596c8-qxlfz 1/1 Running 0 38m
kube-system coredns-8655855d6-blzl5 1/1 Running 0 38m
Confirm that you now have two nodes in your cluster with the following command.
kubectl get nodes -o wide
It should return something like the following.
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k3s-master Ready master 40m v1.18.2+k3s1 172.16.2.128 <none> Ubuntu 18.04.3 LTS 4.15.0-101-generic containerd://1.3.3-k3s2
k3s-node1 Ready <none> 30m v1.18.2+k3s1 172.16.2.129 <none> Ubuntu 18.04.3 LTS 4.15.0-101-generic containerd://1.3.3-k3s2
Congratulations! You now have a multi node K3s cluster equipped with Calico and Traefik.
Next steps​
- Try running the Kubernetes Network policy demo to see live graphical view of network policy in action