쿠버네티스 파드 구성 및 관리

# run으로 배포 시 labels은 run임 [root@m-k8s 6.7]# k run nginx --image=nginx -o yaml --dry-run=client apiVersion: v1 kind: Pod metadata: creationTimestamp: null labels: run: nginx name: nginx spec: containers: - image: nginx name: nginx resources: {} dnsPolicy: ClusterFirst restartPolicy: Always status: {} # create으로 배포 시 labels은 app임 [root@m-k8s 6.7]# k create deployment nginx --image=nginx -o yaml --dry-run=client apiVersion: apps/v1 kind: Deployment metadata: creationTimestamp: null labels: app: nginx name: nginx spec: replicas: 1 selector: matchLabels: app: nginx strategy: {} template: metadata: creationTimestamp: null labels: app: nginx spec: containers: - image: nginx name: nginx resources: {} status: {}

[root@m-k8s 6.7]# k run nginx --image=nginx pod/nginx created [root@m-k8s 6.7]# k get po --show-labels NAME READY STATUS RESTARTS AGE LABELS net 0/1 ImagePullBackOff 0 46h run=net nginx 1/1 Running 0 7s run=nginx # Pod Label 커스텀하기 [root@m-k8s 6.7]# k label pod nginx purpose=web pod/nginx labeled [root@m-k8s 6.7]# k get po --show-labels NAME READY STATUS RESTARTS AGE LABELS net 0/1 ImagePullBackOff 0 46h run=net nginx 1/1 Running 0 39s purpose=web,run=nginx [root@m-k8s 6.7]# k get po -l purpose=web NAME READY STATUS RESTARTS AGE nginx 1/1 Running 0 63s [root@m-k8s 6.7]# k get po -l run NAME READY STATUS RESTARTS AGE net 0/1 ImagePullBackOff 0 46h nginx 1/1 Running 0 70s [root@m-k8s 6.7]# k label pod nginx purpose- pod/nginx labeled

[root@m-k8s 6.7]# ls /etc/kubernetes/manifests etcd.yaml kube-apiserver.yaml kube-controller-manager.yaml kube-scheduler.yaml

[root@m-k8s 7.3]# ls static-pod.yaml [root@m-k8s 7.3]# cp ./* /etc/kubernetes/manifests/ [root@m-k8s 7.3]# k get po -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES net 0/1 ImagePullBackOff 0 46h 172.16.221.158 w1-k8s <none> <none> static-pod-m-k8s 1/1 Running 0 6s 172.16.171.72 m-k8s <none> <none> [root@m-k8s 7.3]# scp ./* w1-k8s:/etc/kubernetes/manifests root@w1-k8s's password: static-pod.yaml 100% 109 44.4KB/s 00:00 [root@m-k8s 7.3]# k get po -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES net 0/1 ImagePullBackOff 0 47h 172.16.221.158 w1-k8s <none> <none> static-pod-m-k8s 1/1 Running 0 3m9s 172.16.171.72 m-k8s <none> <none> static-pod-w1-k8s 1/1 Running 0 8s 172.16.221.165 w1-k8s <none> <none>

[root@m-k8s 7.3]# rm -rf /etc/kubernetes/manifests/static-pod.yaml [root@m-k8s 7.3]# k get po -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES net 0/1 ImagePullBackOff 0 47h 172.16.221.158 w1-k8s <none> <none> static-pod-w1-k8s 1/1 Running 0 3m 172.16.221.165 w1-k8s <none> <none>

apiVersion: v1 kind: Pod metadata: labels: run: pod-always name: pod-always spec: containers: - image: sysnet4admin/net-tools name: net-tools command: ["/bin/sh", "-c"] args: - nslookup kubernetes restartPolicy: Always // or Never or OnFailure [Always인 경우] [root@m-k8s 7.4]# k get po -w NAME READY STATUS RESTARTS AGE net 0/1 ImagePullBackOff 0 47h pod-always 0/1 ContainerCreating 0 1s pod-always 0/1 ContainerCreating 0 2s pod-always 0/1 Completed 0 7s pod-always 0/1 Completed 1 10s pod-always 0/1 CrashLoopBackOff 1 (2s ago) 11s pod-always 0/1 Completed 2 (18s ago) 27s pod-always 0/1 CrashLoopBackOff 2 (2s ago) 29s [Never인 경우] [root@m-k8s 7.4]# k get po -w NAME READY STATUS RESTARTS AGE net 0/1 ImagePullBackOff 0 47h pod-always 0/1 Completed 3 (37s ago) 64s pod-never 0/1 ContainerCreating 0 3s pod-never 0/1 Completed 0 4s pod-never 0/1 Completed 0 4s [OnFailure인 경우] [root@m-k8s 7.4]# k get po -w NAME READY STATUS RESTARTS AGE net 0/1 ImagePullBackOff 0 47h pod-always 0/1 Completed 4 (64s ago) 2m1s pod-never 0/1 Completed 0 60s pod-onfailure 0/1 ContainerCreating 0 2s pod-onfailure 0/1 Completed 0 4s pod-onfailure 0/1 Completed 0 5s [OnFailure인 경우-아규먼트에 오타] [root@m-k8s 7.4]# k get po -w NAME READY STATUS RESTARTS AGE net 0/1 ImagePullBackOff 0 47h pod-onfailure-retry 0/1 ContainerCreating 0 1s pod-onfailure-retry 0/1 ContainerCreating 0 1s pod-onfailure-retry 0/1 Error 0 4s pod-onfailure-retry 0/1 Error 1 (3s ago) 7s pod-onfailure-retry 0/1 CrashLoopBackOff 1 (2s ago) 8s pod-onfailure-retry 0/1 Error 2 (18s ago) 24s

apiVersion: v1 kind: Pod metadata: labels: run: startup-w-others name: startup-w-others spec: containers: - name: tardy-nginx image: sysnet4admin/tardy-nginx startupProbe: exec: command: - cat - /tmp/healthy-on initialDelaySeconds: 10 periodSeconds: 60 livenessProbe: exec: command: - cat - /tmp/healthy-on initialDelaySeconds: 10 periodSeconds: 10 readinessProbe: exec: command: - cat - /tmp/healthy-on initialDelaySeconds: 5 periodSeconds: 5

apiVersion: v1 kind: Pod metadata: labels: run: liveness-exec name: liveness-exec spec: containers: - name: tardy-nginx image: sysnet4admin/tardy-nginx livenessProbe: exec: command: - cat - /tmp/healthy-on initialDelaySeconds: 10 periodSeconds: 10 #it cannot start properly --------------------------------------------------- apiVersion: v1 kind: Pod metadata: labels: run: liveness-httpget name: liveness-httpget spec: containers: - name: healthz-nginx image: sysnet4admin/healthz-nginx livenessProbe: httpGet: path: /healthz port: 80 httpHeaders: - name: purpose value: health-check initialDelaySeconds: 3 periodSeconds: 3 --------------------------------------------------- apiVersion: v1 kind: Pod metadata: labels: run: liveness-tcpsocket name: liveness-tcpsocket spec: containers: - name: healthz-nginx image: sysnet4admin/healthz-nginx livenessProbe: tcpSocket: port: 80 initialDelaySeconds: 3 periodSeconds: 3

apiVersion: v1 kind: Pod metadata: labels: run: readiness-exec name: readiness-exec spec: containers: - name: tardy-nginx image: sysnet4admin/tardy-nginx readinessProbe: exec: command: - cat - /tmp/healthy-on initialDelaySeconds: 10 periodSeconds: 5 --- apiVersion: v1 kind: Service metadata: name: readiness-exec-lb spec: selector: run: readiness-exec ports: - name: http port: 80 targetPort: 80 type: LoadBalancer

[root@m-k8s 7.6]# cat pod-initContainers.yaml apiVersion: v1 kind: Pod metadata: name: pod-initcontainers labels: app: nginx spec: containers: - name: web-page image: nginx volumeMounts: - mountPath: /usr/share/nginx/html name: empty-directory initContainers: - name: html-builder image: alpine volumeMounts: - mountPath: /html-dir name: empty-directory command: ["/bin/sh", "-c"] args: - echo "This page created on $(date +%Y-%m-%d) by initContainers" > /html-dir/index.html; volumes: - name: empty-directory emptyDir: {} # InitContainers는 초기화할때만 사용되므로 READY가 1개이다. [root@m-k8s 7.6]# k get po -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES net 0/1 ImagePullBackOff 0 5d1h 172.16.221.158 w1-k8s <none> <none> pod-initcontainers 0/1 PodInitializing 0 9s 172.16.132.52 w3-k8s <none> <none> [root@m-k8s 7.6]# k get po -o wide w [root@m-k8s 7.6]# k get po -o wide -w NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES net 0/1 ImagePullBackOff 0 5d1h 172.16.221.158 w1-k8s <none> <none> pod-initcontainers 1/1 Running 0 19s 172.16.132.52 w3-k8s <none> <none>

nginx-conf.yaml pod-adapter.yaml [root@m-k8s 7.7]# cat pod-adapter.yaml apiVersion: v1 kind: Pod metadata: name: pod-adapter labels: app: nginx spec: containers: - name: web-page image: nginx volumeMounts: - mountPath: /etc/nginx/conf.d name: nginx-conf - name: adapter image: nginx/nginx-prometheus-exporter:0.9.0 env: - name: SCRAPE_URI value: http://localhost/stub_status ports: - containerPort: 9113 volumes: - name: nginx-conf configMap: name: nginx-conf items: - key: default.conf path: default.conf [root@m-k8s ch7]# k apply -f 7.7 configmap/nginx-conf created pod/pod-adapter created [root@m-k8s ch7]# k get po -w NAME READY STATUS RESTARTS AGE net 0/1 ImagePullBackOff 0 5d21h pod-adapter 0/2 ContainerCreating 0 3s pod-initcontainers 1/1 Running 0 19h pod-adapter 2/2 Running 0 11s ^C[root@m-k8s ch7]# k get po -wide Error: unknown shorthand flag: 'i' in -ide See 'kubectl get --help' for usage. [root@m-k8s ch7]# k get p -o wide error: the server doesn't have a resource type "p" [root@m-k8s ch7]# k get po -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES net 0/1 ImagePullBackOff 0 5d21h 172.16.221.158 w1-k8s <none> <none> pod-adapter 2/2 Running 0 54s 172.16.132.54 w3-k8s <none> <none> pod-initcontainers 1/1 Running 0 19h 172.16.103.182 w2-k8s <none> <none> [root@m-k8s ch7]# curl 172.16.132.54/stub_status Active connections: 1 server accepts handled requests 2 2 2 Reading: 0 Writing: 1 Waiting: 0 [root@m-k8s ch7]# curl 172.16.132.54:9113/metrics # HELP nginx_connections_accepted Accepted client connections # TYPE nginx_connections_accepted counter nginx_connections_accepted 3 # HELP nginx_connections_active Active client connections # TYPE nginx_connections_active gauge nginx_connections_active 1 # HELP nginx_connections_handled Handled client connections # TYPE nginx_connections_handled counter nginx_connections_handled 3 # HELP nginx_connections_reading Connections where NGINX is reading the request header # TYPE nginx_connections_reading gauge nginx_connections_reading 0 # HELP nginx_connections_waiting Idle client connections # TYPE nginx_connections_waiting gauge nginx_connections_waiting 0 # HELP nginx_connections_writing Connections where NGINX is writing the response back to the client # TYPE nginx_connections_writing gauge nginx_connections_writing 1 # HELP nginx_http_requests_total Total http requests # TYPE nginx_http_requests_total counter nginx_http_requests_total 3 # HELP nginx_up Status of the last metric scrape # TYPE nginx_up gauge nginx_up 1 # HELP nginxexporter_build_info Exporter build information # TYPE nginxexporter_build_info gauge nginxexporter_build_info{commit="5f88afbd906baae02edfbab4f5715e06d88538a0",date="2021-03-22T20:16:09Z",version="0.9.0"} 1