Pengertian Node
Node merupakan sebuah mesin worker di dalam Kubernetes, yang sebelumnya dinamakan minion. Sebuah node bisa berupa VM ataupun mesin fisik, tergantung dari klaster-nya. Masing-masing node berisi beberapa servis yang berguna untuk menjalankan banyak pod dan diatur oleh komponen-komponen yang dimiliki oleh master. Servis-servis di dalam sebuah node terdiri dari runtime kontainer, kubelet dan kube-proxy.
Melihat Semua Node
kubectl get node
dwinar@master-kubernetes:~$ kubectl get node NAME STATUS ROLES AGE VERSION master-kubernetes Ready master 53d v1.16.3 node1-kubernetes Ready 53d v1.16.3 node2-kubernetes Ready 53d v1.16.3 dwinar@master-kubernetes:~$
Melihat Detail Node
kubectl describe node namanode
dwinar@master-kubernetes:~$ kubectl describe node master-kubernetes
Name: master-kubernetes
Roles: master
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/arch=amd64
kubernetes.io/hostname=master-kubernetes
kubernetes.io/os=linux
node-role.kubernetes.io/master=
Annotations: flannel.alpha.coreos.com/backend-data: {"VtepMAC":"b2:c4:d8:9f:97:c2"}
flannel.alpha.coreos.com/backend-type: vxlan
flannel.alpha.coreos.com/kube-subnet-manager: true
flannel.alpha.coreos.com/public-ip: 10.0.2.15
kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock
node.alpha.kubernetes.io/ttl: 0
volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp: Sun, 01 Dec 2019 16:30:29 +0700
Taints: node-role.kubernetes.io/master:NoSchedule
Unschedulable: false
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason Message
---- ------ ----------------- ------------------ ------ -------
MemoryPressure False Fri, 24 Jan 2020 10:34:14 +0700 Sun, 01 Dec 2019 16:30:24 +0700 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Fri, 24 Jan 2020 10:34:14 +0700 Sun, 01 Dec 2019 16:30:24 +0700 KubeletHasNoDiskPressure kubelet has no disk pressure
PIDPressure False Fri, 24 Jan 2020 10:34:14 +0700 Sun, 01 Dec 2019 16:30:24 +0700 KubeletHasSufficientPID kubelet has sufficient PID available
Ready True Fri, 24 Jan 2020 10:34:14 +0700 Sun, 01 Dec 2019 16:34:00 +0700 KubeletReady kubelet is posting ready status. AppArmor enabled
Addresses:
InternalIP: 192.168.137.2
Hostname: master-kubernetes
Capacity:
cpu: 2
ephemeral-storage: 19525500Ki
hugepages-2Mi: 0
memory: 2047936Ki
pods: 110
Allocatable:
cpu: 2
ephemeral-storage: 17994700771
hugepages-2Mi: 0
memory: 1945536Ki
pods: 110
System Info:
Machine ID: c332818dca5d7f02c8dec6b35de36933
System UUID: 04ECCD20-A71A-41B9-989D-0BCC021BB333
Boot ID: 5f5ea100-ec47-47b2-b955-fbf04f0b38a9
Kernel Version: 4.4.0-169-generic
OS Image: Ubuntu 16.04.6 LTS
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://17.3.3
Kubelet Version: v1.16.3
Kube-Proxy Version: v1.16.3
PodCIDR: 10.244.0.0/24
PodCIDRs: 10.244.0.0/24
Non-terminated Pods: (8 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits AGE
--------- ---- ------------ ---------- --------------- ------------- ---
kube-system coredns-5644d7b6d9-7vq5b 100m (5%) 0 (0%) 70Mi (3%) 170Mi (8%) 53d
kube-system coredns-5644d7b6d9-cxxfx 100m (5%) 0 (0%) 70Mi (3%) 170Mi (8%) 53d
kube-system etcd-master-kubernetes 0 (0%) 0 (0%) 0 (0%) 0 (0%) 53d
kube-system kube-apiserver-master-kubernetes 250m (12%) 0 (0%) 0 (0%) 0 (0%) 53d
kube-system kube-controller-manager-master-kubernetes 200m (10%) 0 (0%) 0 (0%) 0 (0%) 53d
kube-system kube-flannel-ds-amd64-lnj6k 100m (5%) 100m (5%) 50Mi (2%) 50Mi (2%) 53d
kube-system kube-proxy-d77ct 0 (0%) 0 (0%) 0 (0%) 0 (0%) 53d
kube-system kube-scheduler-master-kubernetes 100m (5%) 0 (0%) 0 (0%) 0 (0%) 53d
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.)
Resource Requests Limits
-------- -------- ------
cpu 850m (42%) 100m (5%)
memory 190Mi (10%) 390Mi (20%)
ephemeral-storage 0 (0%) 0 (0%)
Events:
dwinar@master-kubernetes:~$Pengertian Pod
Pod adalah unit terkecil yang bisa di deploy di Kubernetes Cluster. Pod berisi satu atau lebih container. Secara sederhana Pod adalah aplikasi kita yang running di Kubernetes Cluster.
Melihat Semua Pod
kubectl get pod
dwinar@master-kubernetes:~$ kubectl get pod NAME READY STATUS RESTARTS AGE myapp-pod 1/1 Running 0 132m dwinar@master-kubernetes:~$
Melihat Detail Pod
kubectl describe pod namapod
dwinar@master-kubernetes:~$ kubectl describe pod myapp-pod
Name: myapp-pod
Namespace: default
Priority: 0
Node: node2-kubernetes/192.168.137.4
Start Time: Fri, 24 Jan 2020 08:22:35 +0700
Labels: app=myapp
Annotations:
Status: Running
IP: 10.244.2.5
IPs:
IP: 10.244.2.5
Containers:
nginx:
Container ID: docker://c8e097fe30e068610f29041efdbd3712f8fd6734e559573b05dc917c2a42e118
Image: nginx
Image ID: docker-pullable://nginx@sha256:70821e443be75ea38bdf52a974fd2271babd5875b2b1964f05025981c75a6717
Port:
Host Port:
State: Running
Started: Fri, 24 Jan 2020 08:22:56 +0700
Ready: True
Restart Count: 0
Environment:
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-j5zjq (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
default-token-j5zjq:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-j5zjq
Optional: false
QoS Class: BestEffort
Node-Selectors:
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
dwinar@master-kubernetes:~$Membuat Pod
Buat sebuat file yaml, lalu masukan isikan dengan isian berikut
apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - name: nginx image: nginx
Jalankan perintah berikut untuk membuat sebuah pod.
kubectl create -f filepod.yaml
Melihat Pod
kubectl get pod
dwinar@master-kubernetes:~$ kubectl get pod NAME READY STATUS RESTARTS AGE myapp-pod 1/1 Running 0 135m dwinar@master-kubernetes:~$
kubectl get pod -o wide
dwinar@master-kubernetes:~$ kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES myapp-pod 1/1 Running 0 136m 10.244.2.5 node2-kubernetes dwinar@master-kubernetes:~$