네임스페이스
단일 클러스터 내에서의 리소스 그룹 격리 메커니즘 제공하여 논리적 격리 제공
[root@master ~]# kubectl get namespace
NAME STATUS AGE
default Active 4h13m
kube-node-lease Active 4h13m
kube-public Active 4h13m
kube-system Active 4h13m- kube-system
기본적으로 kubernetes가 동작하기 위해 필요한 pod 및 자원들을 격리시켜 관리하는 namespace - default
namespace를 따로 지정하지 않을 경우, 기본 설정 namespace
실습 :: namespace 생성
[root@master ~/kube/05]# kubectl create namespace myns1
namespace/myns1 created
[root@master ~/kube/05]# kubectl get namespace
NAME STATUS AGE
default Active 4h20m
kube-node-lease Active 4h20m
kube-public Active 4h20m
kube-system Active 4h20m
myns1 Active 5s실습 :: namespace yaml 파일로 생성
[root@master ~/kube/05]# kubectl create namespace myns2 --dry-run=client -o yaml > myns2.yaml
[root@master ~/kube/05]# ls
api myns1.yaml myns2.yaml namespace web1-pod.yaml
[root@master ~/kube/05]# cat myns2.yaml
apiVersion: v1
kind: Namespace
metadata:
creationTimestamp: null
name: myns2
spec: {}
status: {}
[root@master ~/kube/05]# vi myns2.yaml
[root@master ~/kube/05]# cat myns2.yaml
apiVersion: v1
kind: Namespace
metadata:
name: myns2
[root@master ~/kube/05]# kubectl create -f myns2.yaml
namespace/myns2 created
[root@master ~/kube/05]# kubectl create -f web2-pod.yaml -n myns2
pod/web1-pod created
[root@master ~/kube/05]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
web1-pod 1/1 Running 0 6m12s 10.233.102.133 node1 <none> <none>
webserver1 1/1 Running 0 24m 10.233.75.5 node2 <none> <none>
[root@master ~/kube/05]# kubectl get pod -n myns2
NAME READY STATUS RESTARTS AGE
web1-pod 1/1 Running 0 30s
실습 :: yaml 파일로 namespace 지정하여 pod 생성
[root@master ~/kube/05]# kubectl create namespace myns3
namespace/myns3 created
[root@master ~/kube/05]# kubectl get namespaces
NAME STATUS AGE
default Active 4h26m
kube-node-lease Active 4h26m
kube-public Active 4h26m
kube-system Active 4h26m
myns1 Active 5m39s
myns2 Active 86s
myns3 Active 7s
[root@master ~/kube/05]# vi web3-pod.yaml
[root@master ~/kube/05]# cat web3-pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: web3-pod
namespace: myns3
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
protocol: TCP
[root@master ~/kube/05]# kubectl create -f web3-pod.yaml
pod/web3-pod created
[root@master ~/kube/05]# kubectl get pod -n myns3
NAME READY STATUS RESTARTS AGE
web3-pod 1/1 Running 0 7s실습 :: yaml 파일을 통해 ns와 pod 동시 생성
[root@master ~/kube/05]# vi web4-pod.yaml
[root@master ~/kube/05]# cat web4-pod.yaml
apiVersion: v1
kind: Namespace
metadata:
name: myns4
---
apiVersion: v1
kind: Pod
metadata:
name: web4-pod
namespace: myns4
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
protocol: TCP
[root@master ~/kube/05]# kubectl apply -f web4-pod.yaml
namespace/myns4 created
pod/web4-pod created
[root@master ~/kube/05]# kubectl get po -n myns4
NAME READY STATUS RESTARTS AGE
web4-pod 1/1 Running 0 15s실습 :: 현재 사용중인 context 확인 및 변경
[root@master ~/kube/05]# kubectl create ns myns5
namespace/myns5 created
[root@master ~/kube/05]# kubectl config view
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: DATA+OMITTED
server: <https://127.0.0.1:6443>
name: cluster.local
contexts:
- context:
cluster: cluster.local
user: kubernetes-admin
name: kubernetes-admin@cluster.local
current-context: kubernetes-admin@cluster.local
kind: Config
preferences: {}
users:
- name: kubernetes-admin
user:
client-certificate-data: DATA+OMITTED
client-key-data: DATA+OMITTED
[root@master ~/kube/05]# kubectl config set-context kubernetes-user@cluster.local --cluster=cluster.local --user=kubernetes-admin --namespace=myns5
Context "kubernetes-user@cluster.local" created.
[root@master ~/kube/05]# kubectl config view
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: DATA+OMITTED
server: <https://127.0.0.1:6443>
name: cluster.local
contexts:
- context:
cluster: cluster.local
user: kubernetes-admin
name: kubernetes-admin@cluster.local
- context:
cluster: cluster.local
namespace: myns5
user: kubernetes-admin
name: kubernetes-user@cluster.local
current-context: kubernetes-admin@cluster.local
kind: Config
preferences: {}
users:
- name: kubernetes-admin
user:
client-certificate-data: DATA+OMITTED
client-key-data: DATA+OMITTED
[root@master ~/kube/05]# kubectl config use-context kubernetes-user@cluster.local
Switched to context "kubernetes-user@cluster.local".
[root@master ~/kube/05]# kubectl config view
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: DATA+OMITTED
server: <https://127.0.0.1:6443>
name: cluster.local
contexts:
- context:
cluster: cluster.local
user: kubernetes-admin
name: kubernetes-admin@cluster.local
- context:
cluster: cluster.local
namespace: myns5
user: kubernetes-admin
name: kubernetes-user@cluster.local
current-context: kubernetes-user@cluster.local
kind: Config
preferences: {}
users:
- name: kubernetes-admin
user:
client-certificate-data: DATA+OMITTED
client-key-data: DATA+OMITTED
[root@master ~/kube/05]# kubectl run web5-pod --image=nginx --port=80
pod/web5-pod created
[root@master ~/kube/05]# kubectl get pod
NAME READY STATUS RESTARTS AGE
web5-pod 1/1 Running 0 5s
[root@master ~/kube/05]# kubectl get pod -n myns5
NAME READY STATUS RESTARTS AGE
web5-pod 1/1 Running 0 16s
[root@master ~/kube/05]# kubectl get pod -n default
NAME READY STATUS RESTARTS AGE
web1-pod 1/1 Running 0 16m
webserver1 1/1 Running 0 34m▶ context 원상복구
[root@master ~/kube/05]# kubectl config use kubernetes-admin@cluster.local
Switched to context "kubernetes-admin@cluster.local".
[root@master ~/kube/05]# kubectl config view
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: DATA+OMITTED
server: <https://127.0.0.1:6443>
name: cluster.local
contexts:
- context:
cluster: cluster.local
user: kubernetes-admin
name: kubernetes-admin@cluster.local
- context:
cluster: cluster.local
namespace: myns5
user: kubernetes-admin
name: kubernetes-user@cluster.local
current-context: kubernetes-admin@cluster.local
kind: Config
preferences: {}
users:
- name: kubernetes-admin
user:
client-certificate-data: DATA+OMITTED
client-key-data: DATA+OMITTED
[root@master ~/kube/05]# kubectl get pod
NAME READY STATUS RESTARTS AGE
web1-pod 1/1 Running 0 18m
webserver1 1/1 Running 0 36m실습 :: namespace 분리 가능한 resource 확인
NAMESPACED == true :: 분리 가능
NAMESPACED == false :: 분리 불가
[root@master ~/kube/05]# kubectl api-resources | head -10
NAME SHORTNAMES APIVERSION NAMESPACED KIND
bindings v1 true Binding
componentstatuses cs v1 false ComponentStatus
configmaps cm v1 true ConfigMap
endpoints ep v1 true Endpoints
events ev v1 true Event
limitranges limits v1 true LimitRange
namespaces ns v1 false Namespace
nodes no v1 false Node
persistentvolumeclaims pvc v1 true PersistentVolumeClaim