このセクションでは、Kubernetes クラスタを操作するためのコマンドについて紹介します。
docker イメージの確認
docker 上のコンテナを動かすためのイメージを確認する場合は、以下コマンドを実行します。
[root@kube-work2 ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE k8s.gcr.io/kubernetes-dashboard-amd64 v1.10.1 f9aed6605b81 2 weeks ago 122MB k8s.gcr.io/kube-proxy v1.13.1 fdb321fd30a0 3 weeks ago 80.2MB k8s.gcr.io/coredns 1.2.6 f59dcacceff4 2 months ago 40MB quay.io/coreos/flannel v0.10.0-amd64 f0fad859c909 11 months ago 44.6MB k8s.gcr.io/pause 3.1 da86e6ba6ca1 12 months ago 742kB [root@kube-work2 ~]#
docker イメージを削除
docker 上のコンテナを動かすためのイメージを手動で削除する場合は、以下コマンドを実行します。
[root@kube-work2 ~]# docker rmi f9aed6605b81 Untagged: k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.1 Untagged: k8s.gcr.io/kubernetes-dashboard-amd64@sha256:0ae6b69432e78069c5ce2bcde0fe409c5c4d6f0f4d9cd50a17974fea38898747 Deleted: sha256:f9aed6605b814b69e92dece6a50ed1e4e730144eb1cc971389dde9cb3820d124 Deleted: sha256:fbdfe08b001c6861c50073c98ed175d54e2d6440df7b797e52be97df0065098c [root@kube-work2 ~]#
docker 上で稼働しているコンテナを確認
docker 上で稼働しているコンテナを確認する場合は、以下コマンドを実行します。
[root@kube-master ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 3ad21eb237b9 rancher/rancher:v2.0.2 "rancher --http-list…" About a minute ago Up About a minute 0.0.0.0:8080->8080/tcp unruffled_tereshkova e8cf77f4ae07 f0fad859c909 "/opt/bin/flanneld -…" 2 hours ago Up 2 hours k8s_kube-flannel_kube-flannel-ds-amd64-t4bx9_kube-system_5a937115-1040-11e9-98a4-5254008e2308_0 249e4b6fc12a k8s.gcr.io/pause:3.1 "/pause" 2 hours ago Up 2 hours k8s_POD_kube-flannel-ds-amd64-t4bx9_kube-system_5a937115-1040-11e9-98a4-5254008e2308_0 e42cd0a0cb5f fdb321fd30a0 "/usr/local/bin/kube…" 3 hours ago Up 3 hours k8s_kube-proxy_kube-proxy-jt4jq_kube-system_62b0b772-103e-11e9-98a4-5254008e2308_0 dd8fee5ace02 k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_kube-proxy-jt4jq_kube-system_62b0b772-103e-11e9-98a4-5254008e2308_0 205df14953dc ab81d7360408 "kube-scheduler --ad…" 3 hours ago Up 3 hours k8s_kube-scheduler_kube-scheduler-kube-master_kube-system_44b569a35761491825f4e7253fbf0543_0 13ea998f00ac 40a63db91ef8 "kube-apiserver --au…" 3 hours ago Up 3 hours k8s_kube-apiserver_kube-apiserver-kube-master_kube-system_bcc6952e3e0c1f16dbe3b81f2570faef_0 3e4d5435a126 3cab8e1b9802 "etcd --advertise-cl…" 3 hours ago Up 3 hours k8s_etcd_etcd-kube-master_kube-system_6d84a28122b1e72c921e9dec54a60ebf_0 990a37fa3cac 26e6f1db2a52 "kube-controller-man…" 3 hours ago Up 3 hours k8s_kube-controller-manager_kube-controller-manager-kube-master_kube-system_d4ff37ee76fe761a28f11175fd1c384e_0 4985dadd1670 k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_kube-scheduler-kube-master_kube-system_44b569a35761491825f4e7253fbf0543_0 063c91f55594 k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_kube-controller-manager-kube-master_kube-system_d4ff37ee76fe761a28f11175fd1c384e_0 221859f6e75b k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_kube-apiserver-kube-master_kube-system_bcc6952e3e0c1f16dbe3b81f2570faef_0 abbb7847c596 k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_etcd-kube-master_kube-system_6d84a28122b1e72c921e9dec54a60ebf_0 [root@kube-master ~]#
docker 上で停止しているコンテナを確認
docker 上で停止しているコンテナを確認する場合は、以下コマンドを実行します。
[root@kube-master ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES b5a93cbe07ea rancher/rancher:latest "entrypoint.sh" 27 minutes ago Exited (137) 21 minutes ago stupefied_sinoussi e8cf77f4ae07 f0fad859c909 "/opt/bin/flanneld -…" 2 hours ago Up 2 hours k8s_kube-flannel_kube-flannel-ds-amd64-t4bx9_kube-system_5a937115-1040-11e9-98a4-5254008e2308_0 c3d62dde97b3 f0fad859c909 "cp -f /etc/kube-fla…" 2 hours ago Exited (0) 2 hours ago k8s_install-cni_kube-flannel-ds-amd64-t4bx9_kube-system_5a937115-1040-11e9-98a4-5254008e2308_0 249e4b6fc12a k8s.gcr.io/pause:3.1 "/pause" 2 hours ago Up 2 hours k8s_POD_kube-flannel-ds-amd64-t4bx9_kube-system_5a937115-1040-11e9-98a4-5254008e2308_0 e42cd0a0cb5f fdb321fd30a0 "/usr/local/bin/kube…" 3 hours ago Up 3 hours k8s_kube-proxy_kube-proxy-jt4jq_kube-system_62b0b772-103e-11e9-98a4-5254008e2308_0 dd8fee5ace02 k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_kube-proxy-jt4jq_kube-system_62b0b772-103e-11e9-98a4-5254008e2308_0 205df14953dc ab81d7360408 "kube-scheduler --ad…" 3 hours ago Up 3 hours k8s_kube-scheduler_kube-scheduler-kube-master_kube-system_44b569a35761491825f4e7253fbf0543_0 13ea998f00ac 40a63db91ef8 "kube-apiserver --au…" 3 hours ago Up 3 hours k8s_kube-apiserver_kube-apiserver-kube-master_kube-system_bcc6952e3e0c1f16dbe3b81f2570faef_0 3e4d5435a126 3cab8e1b9802 "etcd --advertise-cl…" 3 hours ago Up 3 hours k8s_etcd_etcd-kube-master_kube-system_6d84a28122b1e72c921e9dec54a60ebf_0 990a37fa3cac 26e6f1db2a52 "kube-controller-man…" 3 hours ago Up 3 hours k8s_kube-controller-manager_kube-controller-manager-kube-master_kube-system_d4ff37ee76fe761a28f11175fd1c384e_0 4985dadd1670 k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_kube-scheduler-kube-master_kube-system_44b569a35761491825f4e7253fbf0543_0 063c91f55594 k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_kube-controller-manager-kube-master_kube-system_d4ff37ee76fe761a28f11175fd1c384e_0 221859f6e75b k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_kube-apiserver-kube-master_kube-system_bcc6952e3e0c1f16dbe3b81f2570faef_0 abbb7847c596 k8s.gcr.io/pause:3.1 "/pause" 3 hours ago Up 3 hours k8s_POD_etcd-kube-master_kube-system_6d84a28122b1e72c921e9dec54a60ebf_0 [root@kube-master ~]#
docker 上で稼働しているコンテナを停止
docker 上のコンテナを手動で停止する場合は、以下コマンドを実行します。
[root@kube-master ~]# docker stop 3ad21eb237b9 3ad21eb237b9 [root@kube-master ~]#
Pod の詳細を一覧表示
Pod の詳細を一覧で表示する場合には、以下コマンドを実行します。詳細を一覧表示することで、 Pod の IPアドレスと Pod が稼働している Node を一覧で確認することができます。
[root@kube-master sample-replicaset]# kubectl get pods -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES sample-rs-46pv5 1/1 Running 0 4m52s 10.244.1.107 kube-work1 <none> <none> sample-rs-p4zqm 1/1 Running 0 4m52s 10.244.2.26 kube-work2 <none> <none> sample-rs-tq7j8 1/1 Running 0 2m54s 10.244.1.108 kube-work1 <none> <none> [root@kube-master sample-replicaset]#
YAML 形式で Pod のリストを出力
[root@kube-master manifest]# kubectl get pods -o yaml
apiVersion: v1
items:
- apiVersion: v1
kind: Pod
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"name":"sample-pod","namespace":"default"},"spec":{"containers":[{"image":"nginx:1.13","name":"nginx-container"}]}}
creationTimestamp: "2019-01-07T13:41:56Z"
name: sample-pod
namespace: default
resourceVersion: "301062"
selfLink: /api/v1/namespaces/default/pods/sample-pod
uid: ffbdc4b7-1281-11e9-94ad-525400bc2a02
spec:
containers:
- image: nginx:1.13
imagePullPolicy: IfNotPresent
name: nginx-container
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: default-token-75dfq
readOnly: true
dnsPolicy: ClusterFirst
enableServiceLinks: true
nodeName: kube-work2
priority: 0
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- name: default-token-75dfq
secret:
defaultMode: 420
secretName: default-token-75dfq
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2019-01-07T13:41:56Z"
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: "2019-01-07T13:41:57Z"
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: "2019-01-07T13:41:57Z"
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: "2019-01-07T13:41:56Z"
status: "True"
type: PodScheduled
containerStatuses:
- containerID: docker://bb426ed56436f4b31512812445eaefca65f88291da3bb4915a015b442ac52ef0
image: nginx:1.13
imageID: docker-pullable://nginx@sha256:b1d09e9718890e6ebbbd2bc319ef1611559e30ce1b6f56b2e3b479d9da51dc35
lastState: {}
name: nginx-container
ready: true
restartCount: 0
state:
running:
startedAt: "2019-01-07T13:41:56Z"
hostIP: 192.168.25.102
phase: Running
podIP: 10.244.2.36
qosClass: BestEffort
startTime: "2019-01-07T13:41:56Z"
kind: List
metadata:
resourceVersion: ""
selfLink: ""
[root@kube-master manifest]#
特定のネームスペースの Pod を確認
特定のネームスペースの Pod リソースを確認する場合には、以下コマンドを実行します。ここでは、 Kubernetes クラスタのコンポーネントやアドオンがデプロイされる kube-system のネットワークスペースの Pod を確認しています。
[root@kube-master ~]# kubectl --namespace=kube-system get all NAME READY STATUS RESTARTS AGE pod/coredns-86c58d9df4-c58n7 1/1 Running 0 55m pod/coredns-86c58d9df4-xdzp9 1/1 Running 0 55m pod/etcd-kube-master 1/1 Running 0 54m pod/kube-apiserver-kube-master 1/1 Running 0 53m pod/kube-controller-manager-kube-master 1/1 Running 0 54m pod/kube-flannel-ds-amd64-fghxk 1/1 Running 0 52m pod/kube-flannel-ds-amd64-sxf7h 1/1 Running 0 54m pod/kube-flannel-ds-amd64-xdn8d 1/1 Running 0 53m pod/kube-proxy-gj7d9 1/1 Running 0 55m pod/kube-proxy-tdqwj 1/1 Running 0 53m pod/kube-proxy-vg2b4 1/1 Running 0 52m pod/kube-scheduler-kube-master 1/1 Running 0 54m NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP 55m NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE daemonset.apps/kube-flannel-ds-amd64 3 3 3 3 3 beta.kubernetes.io/arch=amd64 54m daemonset.apps/kube-flannel-ds-arm 0 0 0 0 0 beta.kubernetes.io/arch=arm 54m daemonset.apps/kube-flannel-ds-arm64 0 0 0 0 0 beta.kubernetes.io/arch=arm64 54m daemonset.apps/kube-flannel-ds-ppc64le 0 0 0 0 0 beta.kubernetes.io/arch=ppc64le 54m daemonset.apps/kube-flannel-ds-s390x 0 0 0 0 0 beta.kubernetes.io/arch=s390x 54m daemonset.apps/kube-proxy 3 3 3 3 3 <none> 55m NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/coredns 2/2 2 2 55m NAME DESIRED CURRENT READY AGE replicaset.apps/coredns-86c58d9df4 2 2 2 55m [root@kube-master ~]#
特定のネームスペースの 特定のPod を確認
特定のネームスペースに登録されている特定の Pod リソースの詳細情報を確認したい場合には、以下コマンドを実行します。ここでは、kube-system ネームスペース の kube-scheduler-kube-master というPod リソースの詳細情報を確認しています。
[root@kube-master ~]# kubectl --namespace=kube-system describe pod kube-scheduler-kube-master
Name: kube-scheduler-kube-master
Namespace: kube-system
Priority: 2000000000
PriorityClassName: system-cluster-critical
Node: kube-master/192.168.25.100
Start Time: Sat, 05 Jan 2019 10:21:40 +0900
Labels: component=kube-scheduler
tier=control-plane
Annotations: kubernetes.io/config.hash: 44b569a35761491825f4e7253fbf0543
kubernetes.io/config.mirror: 44b569a35761491825f4e7253fbf0543
kubernetes.io/config.seen: 2019-01-05T10:21:40.654558122+09:00
kubernetes.io/config.source: file
scheduler.alpha.kubernetes.io/critical-pod:
Status: Running
IP: 192.168.25.100
Containers:
kube-scheduler:
Container ID: docker://ac31ca7f12fc252d6b7847639853f53ecc70e65198874e06203b2c1fe764d432
Image: k8s.gcr.io/kube-scheduler:v1.13.1
Image ID: docker-pullable://k8s.gcr.io/kube-scheduler@sha256:4165e5f0d569b5b5e3bd90d78c30c5408b2c938d719939490299ab4cee9a9c0f
Port: <none>
Host Port: <none>
Command:
kube-scheduler
--address=127.0.0.1
--kubeconfig=/etc/kubernetes/scheduler.conf
--leader-elect=true
State: Running
Started: Sat, 05 Jan 2019 10:21:42 +0900
Ready: True
Restart Count: 0
Requests:
cpu: 100m
Liveness: http-get http://127.0.0.1:10251/healthz delay=15s timeout=15s period=10s #success=1 #failure=8
Environment: <none>
Mounts:
/etc/kubernetes/scheduler.conf from kubeconfig (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
kubeconfig:
Type: HostPath (bare host directory volume)
Path: /etc/kubernetes/scheduler.conf
HostPathType: FileOrCreate
QoS Class: Burstable
Node-Selectors: <none>
Tolerations: :NoExecute
Events: <none>
[root@kube-master ~]#
特定のネームスペースの特定の Pod のログ確認
特定のネームスペースに登録されている特定の Pod リソースのログ情報を確認する場合には、以下コマンドを実行します。ここでは、kube-system ネームスペース の kube-scheduler-kube-master というPod リソースのログ情報を確認しています。
root@kube-master ~]# kubectl --namespace=kube-system logs kube-scheduler-kube-master I0105 01:21:42.414863 1 serving.go:318] Generated self-signed cert in-memory W0105 01:21:42.664463 1 authentication.go:249] No authentication-kubeconfig provided in order to lookup client-ca-file in configmap/extension-apiserver-authentication in kube-system, so client certificate authentication won't work. W0105 01:21:42.664476 1 authentication.go:252] No authentication-kubeconfig provided in order to lookup requestheader-client-ca-file in configmap/extension-apiserver-authentication in kube-system, so request-header client certificate authentication won't work. W0105 01:21:42.664488 1 authorization.go:146] No authorization-kubeconfig provided, so SubjectAccessReview of authorization tokens won't work. I0105 01:21:42.667968 1 server.go:150] Version: v1.13.1 I0105 01:21:42.667995 1 defaults.go:210] TaintNodesByCondition is enabled, PodToleratesNodeTaints predicate is mandatory W0105 01:21:42.668500 1 authorization.go:47] Authorization is disabled W0105 01:21:42.668506 1 authentication.go:55] Authentication is disabled I0105 01:21:42.668514 1 deprecated_insecure_serving.go:49] Serving healthz insecurely on 127.0.0.1:10251 I0105 01:21:42.669086 1 secure_serving.go:116] Serving securely on [::]:10259 E0105 01:21:46.498197 1 reflector.go:134] k8s.io/kubernetes/cmd/kube-scheduler/app/server.go:232: Failed to list *v1.Pod: pods is forbidden: User "system:kube-scheduler" cannot list resource "pods" in API group "" at the cluster scope [root@kube-master ~]#
全てのリソースの一覧を確認
Pod や Node などのリソース種別を個別に指定せず、全てのリソースの一覧を取得する場合には、以下コマンドを実行します。ここでは、Pod リソースと Service リソースの一覧が取得されています。
[root@kube-master manifest]# kubectl get all NAME READY STATUS RESTARTS AGE pod/sample-pod 1/1 Running 0 5m34s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 45h [root@kube-master manifest]#
リソースの詳細情報を取得
あるリソースの詳細情報を取得する場合には、以下のようなコマンドを実行します。ここでは、sample-pod という名前の Pod リソースの詳細情報を取得しています。
[root@kube-master manifest]# kubectl describe pod sample-pod
Name: sample-pod
Namespace: default
Priority: 0
PriorityClassName: <none>
Node: kube-work2/192.168.25.102
Start Time: Mon, 07 Jan 2019 22:41:56 +0900
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"name":"sample-pod","namespace":"default"},"spec":{"containers":[{"image":"ng...
Status: Running
IP: 10.244.2.36
Containers:
nginx-container:
Container ID: docker://bb426ed56436f4b31512812445eaefca65f88291da3bb4915a015b442ac52ef0
Image: nginx:1.13
Image ID: docker-pullable://nginx@sha256:b1d09e9718890e6ebbbd2bc319ef1611559e30ce1b6f56b2e3b479d9da51dc35
Port: <none>
Host Port: <none>
State: Running
Started: Mon, 07 Jan 2019 22:41:56 +0900
Ready: True
Restart Count: 0
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-75dfq (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
default-token-75dfq:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-75dfq
Optional: false
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 9m31s default-scheduler Successfully assigned default/sample-pod to kube-work2
Normal Pulled 9m31s kubelet, kube-work2 Container image "nginx:1.13" already present on machine
Normal Created 9m31s kubelet, kube-work2 Created container
Normal Started 9m31s kubelet, kube-work2 Started container
[root@kube-master manifest]#
リソースの使用状況や使用率を確認
あるリソースの使用状況やリソースの使用率を確認する場合には、以下のようなコマンドを実行します。ここでは、kube-work2 という名前の Node の使用状況やリソースの使用率を確認しています。
[root@kube-master manifest]# kubectl describe node kube-work2
Name: kube-work2
Roles: <none>
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=kube-work2
Annotations: flannel.alpha.coreos.com/backend-data: {"VtepMAC":"ae:63:1c:71:3f:c4"}
flannel.alpha.coreos.com/backend-type: vxlan
flannel.alpha.coreos.com/kube-subnet-manager: true
flannel.alpha.coreos.com/public-ip: 192.168.25.102
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: Sat, 05 Jan 2019 11:45:38 +0900
Taints: <none>
Unschedulable: false
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason Message
---- ------ ----------------- ------------------ ------ -------
MemoryPressure False Mon, 07 Jan 2019 22:55:11 +0900 Sun, 06 Jan 2019 23:31:09 +0900 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Mon, 07 Jan 2019 22:55:11 +0900 Sun, 06 Jan 2019 23:31:09 +0900 KubeletHasNoDiskPressure kubelet has no disk pressure
PIDPressure False Mon, 07 Jan 2019 22:55:11 +0900 Sun, 06 Jan 2019 23:31:09 +0900 KubeletHasSufficientPID kubelet has sufficient PID available
Ready True Mon, 07 Jan 2019 22:55:11 +0900 Sun, 06 Jan 2019 23:31:09 +0900 KubeletReady kubelet is posting ready status
OutOfDisk Unknown Sat, 05 Jan 2019 11:45:38 +0900 Sat, 05 Jan 2019 23:53:13 +0900 NodeStatusNeverUpdated Kubelet never posted node status.
Addresses:
InternalIP: 192.168.25.102
Hostname: kube-work2
Capacity:
cpu: 2
ephemeral-storage: 38770180Ki
hugepages-1Gi: 0
hugepages-2Mi: 0
memory: 1882188Ki
pods: 110
Allocatable:
cpu: 2
ephemeral-storage: 35730597829
hugepages-1Gi: 0
hugepages-2Mi: 0
memory: 1779788Ki
pods: 110
System Info:
Machine ID: cf773ef721dcef2ed5b47fce59a84182
System UUID: CF773EF7-21DC-EF2E-D5B4-7FCE59A84182
Boot ID: c1ba0154-9a21-4bb6-8460-c218352b2c62
Kernel Version: 3.10.0-957.1.3.el7.x86_64
OS Image: CentOS Linux 7 (Core)
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://18.9.0
Kubelet Version: v1.13.1
Kube-Proxy Version: v1.13.1
PodCIDR: 10.244.2.0/24
Non-terminated Pods: (3 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits AGE
--------- ---- ------------ ---------- --------------- ------------- ---
default sample-pod 0 (0%) 0 (0%) 0 (0%) 0 (0%) 13m
kube-system kube-flannel-ds-amd64-w64mv 100m (5%) 100m (5%) 50Mi (2%) 50Mi (2%) 2d11h
kube-system kube-proxy-k76gv 0 (0%) 0 (0%) 0 (0%) 0 (0%) 2d11h
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.)
Resource Requests Limits
-------- -------- ------
cpu 100m (5%) 100m (5%)
memory 50Mi (2%) 50Mi (2%)
ephemeral-storage 0 (0%) 0 (0%)
Events: <none>
[root@kube-master manifest]#
Pod 上でのコマンドの実行
Pod 上で特定のコマンドを実行したい場合には、以下コマンドを実行します。 /bin/sh などのシェルを実行することで、あたかもコンテナに対してログインしているような状態を実行可能となります。
[root@kube-master manifest]# kubectl exec -it sample-pod /bin/sh # # ls -la total 8 drwxr-xr-x. 1 root root 28 Jan 7 13:41 . drwxr-xr-x. 1 root root 28 Jan 7 13:41 .. -rwxr-xr-x. 1 root root 0 Jan 7 13:41 .dockerenv drwxr-xr-x. 2 root root 4096 Apr 26 2018 bin drwxr-xr-x. 2 root root 6 Feb 23 2018 boot drwxr-xr-x. 5 root root 360 Jan 7 13:41 dev drwxr-xr-x. 1 root root 66 Jan 7 13:41 etc drwxr-xr-x. 2 root root 6 Feb 23 2018 home drwxr-xr-x. 1 root root 45 Apr 26 2018 lib drwxr-xr-x. 2 root root 34 Apr 26 2018 lib64 drwxr-xr-x. 2 root root 6 Apr 26 2018 media drwxr-xr-x. 2 root root 6 Apr 26 2018 mnt drwxr-xr-x. 2 root root 6 Apr 26 2018 opt dr-xr-xr-x. 122 root root 0 Jan 7 13:41 proc drwx------. 2 root root 37 Apr 26 2018 root drwxr-xr-x. 1 root root 38 Jan 7 13:41 run drwxr-xr-x. 2 root root 4096 Apr 26 2018 sbin drwxr-xr-x. 2 root root 6 Apr 26 2018 srv dr-xr-xr-x. 13 root root 0 Jan 6 14:30 sys drwxrwxrwt. 1 root root 6 Apr 30 2018 tmp drwxr-xr-x. 1 root root 66 Apr 26 2018 usr drwxr-xr-x. 1 root root 19 Apr 26 2018 var #
exit で 終了します。
# exit [root@kube-master manifest]#
コンテナ内のファイルをローカルにコピー
Pod （コンテナ）内のファイルをローカルへコピーしたい場合には、以下コマンドを実行します。 ここでは、sample-pod という名前のPod内にある v1.7.1.yaml ファイルをローカルにコピーしています。
[root@kube-master ~]# kubectl cp sample-pod:/etc/hostname v1.7.1.yaml tar: Removing leading `/' from member names [root@kube-master ~]#
ローカルマシンのディレクトリを参照します。 v1.7.1.yaml ファイルがコピーされています。
[root@kube-master ~]# ls -la 合計 80 〜（省略）〜 -rw-r--r--. 1 root root 11 1月 13 19:44 pod-nginx.yaml -rw-r--r--. 1 root root 11 1月 13 19:44 v1.7.1.yaml [root@kube-master ~]#
v1.7.1.yaml ファイルの中身を確認します。
[root@kube-master ~]# cat v1.7.1.yaml sample-pod [root@kube-master ~]#
ローカルファイルをコンテナ内にコピー
ローカルのファイルを Pod （コンテナ）内へコピーしたい場合には、以下コマンドを実行します。 ここでは、ローカルにある hostname というファイルを sample-pod という名前の Pod へコピーしています。
[root@kube-master ~]# kubectl cp hostname sample-pod:/tmp/ [root@kube-master ~]#
Pod（コンテナ）内へコピーしたファイルを確認します。
[root@kube-master ~]# kubectl exec -it sample-pod ls /tmp/ hostname [root@kube-master ~]#
kubectl におけるデバッグ
kubectl を使って Kubernetes 上のデバッグログを出力する場合には、以下コマンドを実行します。Kubernetes 上で何かしらエラーがあった場合には、API との通信や kubectl の設定に問題があるケースが多く、その際のトラブルシューティングに活用できます。ここでは、 -v オプションを指定して ログレベル 8 のデバッグログを出力しています。
[root@kube-master ~]# kubectl -v=8 get pod
I0113 20:09:24.387309 28268 loader.go:359] Config loaded from file /etc/kubernetes/admin.conf
I0113 20:09:24.387828 28268 loader.go:359] Config loaded from file /etc/kubernetes/admin.conf
I0113 20:09:24.390550 28268 loader.go:359] Config loaded from file /etc/kubernetes/admin.conf
I0113 20:09:24.397245 28268 loader.go:359] Config loaded from file /etc/kubernetes/admin.conf
I0113 20:09:24.397683 28268 round_trippers.go:416] GET https://192.168.25.100:6443/api/v1/namespaces/default/pods?limit=500
I0113 20:09:24.397694 28268 round_trippers.go:423] Request Headers:
I0113 20:09:24.397700 28268 round_trippers.go:426] Accept: application/json;as=Table;v=v1beta1;g=meta.k8s.io, application/json
I0113 20:09:24.397707 28268 round_trippers.go:426] User-Agent: kubectl/v1.13.1 (linux/amd64) kubernetes/eec55b9
I0113 20:09:24.405241 28268 round_trippers.go:441] Response Status: 200 OK in 7 milliseconds
I0113 20:09:24.405276 28268 round_trippers.go:444] Response Headers:
I0113 20:09:24.405282 28268 round_trippers.go:447] Content-Type: application/json
I0113 20:09:24.405288 28268 round_trippers.go:447] Content-Length: 3634
I0113 20:09:24.405293 28268 round_trippers.go:447] Date: Sun, 13 Jan 2019 11:09:24 GMT
I0113 20:09:24.405382 28268 request.go:942] Response Body: {"kind":"Table","apiVersion":"meta.k8s.io/v1beta1","metadata":{"selfLink":"/api/v1/namespaces/default/pods","resourceVersion":"1014347"},"columnDefinitions":[{"name":"Name","type":"string","format":"name","description":"Name must be unique within a namespace. Is required when creating resources, although some resources may allow a client to request the generation of an appropriate name automatically. Name is primarily intended for creation idempotence and configuration definition. Cannot be updated. More info: http://kubernetes.io/docs/user-guide/identifiers#names","priority":0},{"name":"Ready","type":"string","format":"","description":"The aggregate readiness state of this pod for accepting traffic.","priority":0},{"name":"Status","type":"string","format":"","description":"The aggregate status of the containers in this pod.","priority":0},{"name":"Restarts","type":"integer","format":"","description":"The number of times the containers in this pod have been restarted.","priority":0},{"name":"Age","type":"stri [truncated 2610 chars]
I0113 20:09:24.406206 28268 get.go:563] no kind is registered for the type v1beta1.Table in scheme "k8s.io/kubernetes/pkg/api/legacyscheme/scheme.go:29"
NAME READY STATUS RESTARTS AGE
sample-pod 1/1 Running 0 5d21h
[root@kube-master ~]#