Series: Kubernetes at home

Kubernetes at home - Part 2: The install

In the previous part of this series, I gave a brief layout of the hardware. In this part of the series, I’m going to layout the highlights of the Kubernetes install itself. I’m sticking with as many default settings as I can in order to reduce future mistakes from not yet knowing why I’d change it.

Operating system

The server is running Ubuntu 20.04 LTS at the moment. I value stability. Debugging weird issues isn’t on my TODO list. Having said that, a wide variety of operating systems would work just as well and I might experiment with others if I add more nodes to the cluster.

Steps - kubeadm

Installed containerd

I went ahead and chose containerd as the CRI runtime. The only change in installation was to use systemd cgroup driver.

Installed Kubernetes using Kubeadm

The below kubeadm config.yaml file uses systemd cgroup driver, sets containderd socket, and then also sets a default podSubnet of 10.112.0.0/12 which is planning ahead to enable Calico install.

Edit 2021-01-06: I changed podSubnet from 10.0.0.0/8 to 10.112.0.0/12 to avoid conflict with service cluster ip range of 10.96.0.0/12

config.yml

apiVersion: kubeadm.k8s.io/v1beta2
kind: InitConfiguration
nodeRegistration:
  criSocket: "/run/containerd/containerd.sock"
---
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
networking:
  podSubnet: "10.112.0.0/12"
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
cgroupDriver: "systemd"

> kubeadm init --config config.yml

I went ahead and allowed scheduling on the control-plane node as well since it’s a single node cluster.

Installed Project Calico Networking

For networking, I went ahead and installed Project Calico. I don’t have a good reason to choose it beyond I found it in this documentation list. I’ll stick with Calico so long as it just works.

I gave this server a static IP address of “192.168.0.45” on my home network just to avoid problems with that changing around.

Single node information

Installation went smoothly. When I examine the cluster using kubectl, I see one node and a lot of solid info on it. Admittedly, the actual installation happened a few weeks ago as of time of this blog post being written, so that age on the below info is certainly higher.

daniel@bequiet:~$ kubectl get nodes --all-namespaces 
NAME        STATUS   ROLES                  AGE   VERSION
danielamd   Ready    control-plane,master   18d   v1.20.1
daniel@bequiet:~$ kubectl describe nodes/danielamd
Name:               danielamd
Roles:              control-plane,master
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    kubernetes.io/arch=amd64
                    kubernetes.io/hostname=danielamd
                    kubernetes.io/os=linux
                    node-role.kubernetes.io/control-plane=
                    node-role.kubernetes.io/master=
Annotations:        kubeadm.alpha.kubernetes.io/cri-socket: /run/containerd/containerd.sock
                    node.alpha.kubernetes.io/ttl: 0
                    projectcalico.org/IPv4Address: 192.168.0.45/24
                    projectcalico.org/IPv4IPIPTunnelAddr: 10.133.205.192
                    volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp:  Sat, 12 Dec 2020 01:03:34 -0500
Taints:             <none>
Unschedulable:      false
Lease:
  HolderIdentity:  danielamd
  AcquireTime:     <unset>
  RenewTime:       Wed, 30 Dec 2020 23:54:37 -0500
Conditions:
  Type                 Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
  ----                 ------  -----------------                 ------------------                ------                       -------
  NetworkUnavailable   False   Wed, 30 Dec 2020 00:23:29 -0500   Wed, 30 Dec 2020 00:23:29 -0500   CalicoIsUp                   Calico is running on this node
  MemoryPressure       False   Wed, 30 Dec 2020 23:53:27 -0500   Sat, 12 Dec 2020 01:03:32 -0500   KubeletHasSufficientMemory   kubelet has sufficient memory available
  DiskPressure         False   Wed, 30 Dec 2020 23:53:27 -0500   Sat, 12 Dec 2020 01:03:32 -0500   KubeletHasNoDiskPressure     kubelet has no disk pressure
  PIDPressure          False   Wed, 30 Dec 2020 23:53:27 -0500   Sat, 12 Dec 2020 01:03:32 -0500   KubeletHasSufficientPID      kubelet has sufficient PID available
  Ready                True    Wed, 30 Dec 2020 23:53:27 -0500   Sat, 19 Dec 2020 13:07:37 -0500   KubeletReady                 kubelet is posting ready status. AppArmor enabled
Addresses:
  InternalIP:  192.168.0.45
  Hostname:    danielamd
Capacity:
  cpu:                12
  ephemeral-storage:  479151816Ki
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             65859444Ki
  pods:               110
Allocatable:
  cpu:                12
  ephemeral-storage:  441586312895
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             65757044Ki
  pods:               110
System Info:
  Machine ID:                 <redacted>
  System UUID:                <redacted>
  Boot ID:                    <redacted>
  Kernel Version:             5.4.0-58-generic
  OS Image:                   Ubuntu 20.04.1 LTS
  Operating System:           linux
  Architecture:               amd64
  Container Runtime Version:  containerd://1.4.3
  Kubelet Version:            v1.20.1
  Kube-Proxy Version:         v1.20.1
PodCIDR:                      10.0.0.0/24
PodCIDRs:                     10.0.0.0/24
Non-terminated Pods:          (13 in total)
  Namespace                   Name                                        CPU Requests  CPU Limits  Memory Requests  Memory Limits  AGE
  ---------                   ----                                        ------------  ----------  ---------------  -------------  ---

... <abbreviated> ...

  kube-system                 calico-kube-controllers-744cfdf676-2b9t7    0 (0%)        0 (0%)      0 (0%)           0 (0%)         18d
  kube-system                 calico-node-sq46f                           250m (2%)     0 (0%)      0 (0%)           0 (0%)         18d
  kube-system                 coredns-74ff55c5b-5whx2                     100m (0%)     0 (0%)      70Mi (0%)        170Mi (0%)     18d
  kube-system                 coredns-74ff55c5b-pdfqx                     100m (0%)     0 (0%)      70Mi (0%)        170Mi (0%)     18d
  kube-system                 etcd-danielamd                              100m (0%)     0 (0%)      100Mi (0%)       0 (0%)         18d
  kube-system                 kube-apiserver-danielamd                    250m (2%)     0 (0%)      0 (0%)           0 (0%)         18d
  kube-system                 kube-controller-manager-danielamd           200m (1%)     0 (0%)      0 (0%)           0 (0%)         18d
  kube-system                 kube-proxy-scbhr                            0 (0%)        0 (0%)      0 (0%)           0 (0%)         18d
  kube-system                 kube-scheduler-danielamd                    100m (0%)     0 (0%)      0 (0%)           0 (0%)         18d
Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  Resource           Requests    Limits
  --------           --------    ------
  cpu                1100m (9%)  0 (0%)
  memory             240Mi (0%)  340Mi (0%)
  ephemeral-storage  100Mi (0%)  0 (0%)
  hugepages-1Gi      0 (0%)      0 (0%)
  hugepages-2Mi      0 (0%)      0 (0%)
Events:              <none>

Steps - kubectl

One quick aside, is that installing kubectl via arkade was easy. I found out about it via a Jamie Phillips blog post. Might as well try arkade out for a while.

daniel@bequiet:~$ arkade get kubectl --version v1.20.1
Downloading kubectl
https://storage.googleapis.com/kubernetes-release/release/v1.20.1/bin/linux/amd64/kubectl
38.37 MiB / 38.37 MiB [-----------------------------------------------------------------------------------------] 100.00%
Tool written to: /home/daniel/.arkade/bin/kubectl

# Add (kubectl) to your PATH variable
export PATH=$PATH:$HOME/.arkade/bin/

# Test the binary:
/home/daniel/.arkade/bin/kubectl

# Or install with:
sudo mv /home/daniel/.arkade/bin/kubectl /usr/local/bin/

daniel@bequiet:~$ which kubectl
/home/daniel/.arkade/bin//kubectl
daniel@bequiet:~$ kubectl version
Client Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.1", GitCommit:"c4d752765b3bbac2237bf87cf0b1c2e307844666", GitTreeState:"clean", BuildDate:"2020-12-18T12:09:25Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.0", GitCommit:"af46c47ce925f4c4ad5cc8d1fca46c7b77d13b38", GitTreeState:"clean", BuildDate:"2020-12-08T17:51:19Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"linux/amd64"}

Summary

I have a perfectly fine, until told otherwise, single node kubernetes cluster running. It would be great if I installed applications on it to justify its existence.

OLIVER
CODING

Series: Kubernetes at home

Kubernetes at home - Part 2: The install

Operating system

Steps - kubeadm

Single node information

Steps - kubectl

Summary

Previous: Kubernetes at home - Part 1: The hardware

Previous: Kubernetes at home - Part 1: The hardware

Next: Kubernetes at home - Part 3: HAProxy Ingress

Next: Kubernetes at home - Part 3: HAProxy Ingress

Series: Kubernetes at home

OLIVERCODING

Series: Kubernetes at home

Kubernetes at home - Part 2: The install

Operating system

Steps - kubeadm

Single node information

Steps - kubectl

Summary

Previous: Kubernetes at home - Part 1: The hardware

Previous: Kubernetes at home - Part 1: The hardware

Next: Kubernetes at home - Part 3: HAProxy Ingress

Next: Kubernetes at home - Part 3: HAProxy Ingress

Series: Kubernetes at home

OLIVER
CODING