Nodes
In this session , we will explore the node details
List nodes
$ k8s@k8s-master-01:~$ kubectl get nodesOutput
NAME STATUS ROLES AGE VERSION
k8s-master-01 Ready master 38h v1.13.1
k8s-worker-01 Ready <none> 38h v1.13.1
Extended listing
$ kubectl get nodes -o wideOutput
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k8s-master-01 Ready master 38h v1.13.1 192.168.56.201 <none> Ubuntu 16.04.5 LTS 4.4.0-131-generic docker://18.9.0
k8s-worker-01 Ready <none> 38h v1.13.1 192.168.56.202 <none> Ubuntu 16.04.5 LTS 4.4.0-131-generic docker://18.9.0
k8s@k8s-master-01:~$Details on a node
$ kubectl describe node k8s-master-01Output
Name: k8s-master-01
Roles: master
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=k8s-master-01
node-role.kubernetes.io/master=
Annotations: kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock
node.alpha.kubernetes.io/ttl: 0
projectcalico.org/IPv4Address: 192.168.56.201/24
volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp: Mon, 31 Dec 2018 02:10:05 +0530
Taints: node-role.kubernetes.io/master:NoSchedule
Unschedulable: false
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason Message
---- ------ ----------------- ------------------ ------ -------
MemoryPressure False Tue, 01 Jan 2019 17:01:28 +0530 Mon, 31 Dec 2018 02:10:02 +0530 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Tue, 01 Jan 2019 17:01:28 +0530 Mon, 31 Dec 2018 02:10:02 +0530 KubeletHasNoDiskPressure kubelet has no disk pressure
PIDPressure False Tue, 01 Jan 2019 17:01:28 +0530 Mon, 31 Dec 2018 02:10:02 +0530 KubeletHasSufficientPID kubelet has sufficient PID available
Ready True Tue, 01 Jan 2019 17:01:28 +0530 Mon, 31 Dec 2018 22:59:35 +0530 KubeletReady kubelet is posting ready status. AppArmor enabled
Addresses:
InternalIP: 192.168.56.201
Hostname: k8s-master-01
Capacity:
cpu: 1
ephemeral-storage: 49732324Ki
hugepages-2Mi: 0
memory: 2048168Ki
pods: 110
Allocatable:
cpu: 1
ephemeral-storage: 45833309723
hugepages-2Mi: 0
memory: 1945768Ki
pods: 110
System Info:
Machine ID: 96cedf74a821722b0df5ee775c291ea2
System UUID: 90E04905-218D-4673-A911-9676A65B07C5
Boot ID: 14201246-ab82-421e-94f6-ff0d8ad3ba54
Kernel Version: 4.4.0-131-generic
OS Image: Ubuntu 16.04.5 LTS
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://18.9.0
Kubelet Version: v1.13.1
Kube-Proxy Version: v1.13.1
PodCIDR: 192.168.0.0/24
Non-terminated Pods: (6 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits AGE
--------- ---- ------------ ---------- --------------- ------------- ---
kube-system calico-node-nkcrd 250m (25%) 0 (0%) 0 (0%) 0 (0%) 38h
kube-system etcd-k8s-master-01 0 (0%) 0 (0%) 0 (0%) 0 (0%) 38h
kube-system kube-apiserver-k8s-master-01 250m (25%) 0 (0%) 0 (0%) 0 (0%) 38h
kube-system kube-controller-manager-k8s-master-01 200m (20%) 0 (0%) 0 (0%) 0 (0%) 38h
kube-system kube-proxy-tzznm 0 (0%) 0 (0%) 0 (0%) 0 (0%) 38h
kube-system kube-scheduler-k8s-master-01 100m (10%) 0 (0%) 0 (0%) 0 (0%) 38h
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.)
Resource Requests Limits
-------- -------- ------
cpu 800m (80%) 0 (0%)
memory 0 (0%) 0 (0%)
ephemeral-storage 0 (0%) 0 (0%)
Events: <none>We will discuss more about each of the fields on upcoming sessions.
For now lets discuss about Non-terminated Pods field;
Non-terminated Pods field
- Namespace : The namespace which the Pods were running .
The pods that we create will by default go to
defaultnamespace. - Name : Name of the Pod
- CPU Request : How much CPU resource requested by Pod during startup.
- CPU Limits : How much CPU the Pod can use.
- Memory Request : How much memory requested by Pod during startup.
- Memory Limits : How much memory the Pod can use.