自分で調べたコマンドやtipsを更新するだけ。
人に見せるものではない。
コマンド
| やりたいこと | コマンド | 備考 |
|---|---|---|
| Namespace切り替え | kubectl config set-context $(kubectl config current-context) --namespace=mynamespace | |
| k8s completion | source <(kubectl completion bash) | |
| 情報を横長で見る | kubectl get pods -o wide | |
| podやsvcをdry-runしてmanifestを生成する | kubectl create deploy xxxx --image xxx/xxx -o yaml --dry-run > xxx.yaml | |
| 既存のpodからyamlを出力 | kubectl get pods -o yaml [pod名] | |
| tokenの取得 | kubeadm token list | |
| podのログ確認 | kubectl logs [podname] | |
| kubeletのログ確認 | journalctl -xeu kubelet journalctl -xeu kubelet -o verbose |
nodeを再びクラスタに参加させる方法
- tokenの再発行およびコマンド生成
kubeadm token create --print-join-command
ちなみに再度参加させる場合はkubeletを停止した状態で/etc/kubernetes配下を削除し、上記のコマンドを各ノードで実行する
ファイル
| ファイル名 | 内容 |
|---|---|
| /etc/kubernetes/manifests/etcd.yaml | etcdの設定 |
| /etc/kubernetes/manifests/kube-apiserver.yaml | apiserverの設定 |
| /etc/kubernetes/manifests/kube-controller-manager.yaml | kube-controller-managerの設定 |
| /etc/kubernetes/manifests/kube-scheduler.yaml | kube-schedulerの設定 |
ハンズオン
AWSへのkubernetesのインストール
- kubeadmのインストール - Kubernetes
- How to install Docker CE on RHEL 8 - LinuxConfig.org
- calico-AWS
- Installing Calico for policy and networking (recommended)
- Kubernetes v1.13の構築をkubeadmで行う(Centos7, AWS) - Qiita
- Adding Calico to an Existing Kubernetes Cluster
- コンテナネットワーキング（CNI）最前線
-
環境
- AWS EC2
- OS:RedHat8
- 構成:master x1, node x2
- container:docker-ce(RHEL8はpodman-dockerというのがいるがこれは使わない）
- cni:calico
-
手順
- kubeadm/kubelet/kubectl入れる
- docker-ce入れる
- masterでkubernetes cluster作る
- nodeがclusterに参加する
- calico入れる
0 sudo -s <- rootになっておく
1 cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
exclude=kube*
EOF
3 setenforce 0
4 sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
5 yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
6 systemctl enable --now kubelet
7 cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
8 sysctl --system
9 yum -y install git
10 systemctl daemon-reload
11 systemctl restart kubelet
12 yum -y update
36 yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
37 yum -y install docker-ce --nobest
38 systemctl enable docker
39 systemctl start docker
- master
40 kubeadm init --pod-network-cidr=192.168.0.0/16
44 mkdir -p $HOME/.kube
45 sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
46 sudo chown $(id -u):$(id -g) $HOME/.kube/config
48 echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> .bash_profile
113 curl https://docs.projectcalico.org/v3.8/manifests/calico.yaml -O
114 POD_CIDR="<your-pod-cidr>" sed -i -e "s?192.168.0.0/16?$POD_CIDR?g" calico.yaml
115 cat calico.yaml
116 kubectl apply -f calico.yaml
[root@ip-10-0-0-187 calico]# kubectl get node
NAME STATUS ROLES AGE VERSION
ip-10-0-0-152.ap-northeast-1.compute.internal Ready <none> 13m v1.15.2
ip-10-0-0-187.ap-northeast-1.compute.internal Ready master 17m v1.15.2
ip-10-0-0-237.ap-northeast-1.compute.internal Ready <none> 13m v1.15.2
[root@ip-10-0-0-187 calico]#
- node
kubeadm join 10.0.0.187:6443 --token xxxx --discovery-token-ca-cert-hash sha256:xxxx
-> ミスってkubeadm initを叩きなおしたいならこれ
Istioサンプルアプリ導入
Istio / Bookinfo Application これをやってみた。
起動した後、kubectl get pods -o yaml reviews-v1-5787f7b87-f6ffwをたたいてIstioによって変化した部分を見てみた。（Deploymentについて注目した）
※IstioいれるとEnvoyが勝手にsidecarとして入ってくる
→なんかうまくできていない（Error: missing configuration map key "values" in "istio-sidecar-injector" ってでてきたので、そのうちistioctl kube-inject -f samples/bookinfo/platform/kube/bookinfo.yamlの結果とナチュラルなbookinfo.yamlを比較する。
-apiVersion: apps/v1
+apiVersion: extensions/v1beta1
kind: Deployment
metadata:
- name: reviews-v1
+ annotations:
+ deployment.kubernetes.io/revision: "1"
+ kubectl.kubernetes.io/last-applied-configuration: |
+ {"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"labels":{"app":"reviews","version":"v1"},"name":"reviews-v1","namespace":"test1"},"spec":{"replicas":1,"selector":{"matchLabels":{"app":"reviews","version":"v1"}},"template":{"metadata":{"labels":{"app":"reviews","version":"v1"}},"spec":{"containers":[{"image":"docker.io/istio/examples-bookinfo-reviews-v1:1.15.0","imagePullPolicy":"IfNotPresent","name":"reviews","ports":[{"containerPort":9080}]}],"serviceAccountName":"bookinfo-reviews"}}}}
+ creationTimestamp: 2019-08-14T12:33:28Z
+ generation: 1
labels:
app: reviews
version: v1
+ name: reviews-v1
+ namespace: test1
+ resourceVersion: "13250"
+ selfLink: /apis/extensions/v1beta1/namespaces/test1/deployments/reviews-v1
+ uid: b7bff820-be8f-11e9-ba5f-42010a92009f
spec:
+ progressDeadlineSeconds: 600
replicas: 1
+ revisionHistoryLimit: 10
selector:
matchLabels:
app: reviews
version: v1
+ strategy:
+ rollingUpdate:
+ maxSurge: 25%
+ maxUnavailable: 25%
+ type: RollingUpdate
template:
metadata:
+ creationTimestamp: null
labels:
app: reviews
version: v1
spec:
- serviceAccountName: bookinfo-reviews
containers:
- - name: reviews
- image: docker.io/istio/examples-bookinfo-reviews-v1:1.15.0
+ - image: docker.io/istio/examples-bookinfo-reviews-v1:1.15.0
imagePullPolicy: IfNotPresent
+ name: reviews
ports:
- containerPort: 9080
+ protocol: TCP
+ resources: {}
+ terminationMessagePath: /dev/termination-log
+ terminationMessagePolicy: File
+ dnsPolicy: ClusterFirst
+ restartPolicy: Always
+ schedulerName: default-scheduler
+ securityContext: {}
+ serviceAccount: bookinfo-reviews
+ serviceAccountName: bookinfo-reviews
+ terminationGracePeriodSeconds: 30
+status:
+ availableReplicas: 1
+ conditions:
+ - lastTransitionTime: 2019-08-14T12:34:03Z
+ lastUpdateTime: 2019-08-14T12:34:03Z
+ message: Deployment has minimum availability.
+ reason: MinimumReplicasAvailable
+ status: "True"
+ type: Available
+ - lastTransitionTime: 2019-08-14T12:33:28Z
+ lastUpdateTime: 2019-08-14T12:34:03Z
+ message: ReplicaSet "reviews-v1-5787f7b87" has successfully progressed.
+ reason: NewReplicaSetAvailable
+ status: "True"
+ type: Progressing
+ observedGeneration: 1
+ readyReplicas: 1
+ replicas: 1
+ updatedReplicas: 1
トラブルシュート
calicoが起動しない(CrashLoopBackOff)
[root@ip-10-0-0-187 calico]# kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-kube-controllers-65b8787765-xldtm 0/1 ContainerCreating 0 10m
kube-system calico-node-jmqn2 0/1 CrashLoopBackOff 6 11m
kube-system calico-node-xn8wg 0/1 CrashLoopBackOff 6 11m
kube-system calico-node-xnwq2 0/1 CrashLoopBackOff 7 11m
kube-system coredns-5c98db65d4-crjs2 0/1 ContainerCreating 0 22h
kube-system coredns-5c98db65d4-hlxmg 0/1 ContainerCreating 0 22h
kube-system etcd-ip-10-0-0-187.ap-northeast-1.compute.internal 1/1 Running 0 22h
[root@ip-10-0-0-187 calico]# kubectl logs calico-node-xn8wg -n kube-system
2019-08-16 09:43:07.390 [INFO][8] startup.go 256: Early log level set to info
2019-08-16 09:43:07.390 [INFO][8] startup.go 272: Using NODENAME environment for node name
2019-08-16 09:43:07.390 [INFO][8] startup.go 284: Determined node name: ip-10-0-0-152.ap-northeast-1.compute.internal
2019-08-16 09:43:07.391 [INFO][8] k8s.go 228: Using Calico IPAM
2019-08-16 09:43:07.392 [INFO][8] startup.go 316: Checking datastore connection
2019-08-16 09:43:37.393 [INFO][8] startup.go 331: Hit error connecting to datastore - retry error=Get https://10.96.0.1:443/api/v1/nodes/foo: dial tcp 10.96.0.1:443: i/o timeout
2019-08-16 09:44:08.436 [INFO][8] startup.go 331: Hit error connecting to datastore - retry error=Get https://10.96.0.1:443/api/v1/nodes/foo: dial tcp 10.96.0.1:443: i/o timeout
を参考にAPIserverが使用するセグメントを変更した
/etc/kubernetes/manifests
[root@ip-10-0-0-187 manifests]# grep 20 kube-apiserver.yaml
- --service-cluster-ip-range=20.96.0.0/12
もともと10.96.0.0/12だったが、うまく通信ができていなかった。AWSのVPCが10.0.0.0/8とかなのでセグメントがかぶっていたのではないかと推察している。
[root@ip-10-0-0-187 manifests]# kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-kube-controllers-65b8787765-xldtm 0/1 CrashLoopBackOff 5 74m
kube-system calico-node-jmqn2 1/1 Running 22 74m
kube-system calico-node-xn8wg 1/1 Running 23 74m
kube-system calico-node-xnwq2 1/1 Running 24 74m
kube-system coredns-5c98db65d4-crjs2 0/1 Running 5 23h
kube-system coredns-5c98db65d4-hlxmg 0/1 Error 5 23h
kube-system etcd-ip-10-0-0-187.ap-northeast-1.compute.internal 1/1 Running 1 23h
kube-system kube-apiserver-ip-10-0-0-187.ap-northeast-1.compute.internal 1/1 Running 1 11m
kube-system kube-controller-manager-ip-10-0-0-187.ap-northeast-1.compute.internal 1/1 Running 2 23h
kube-system kube-proxy-mmk8k 1/1 Running 1 23h
kube-system kube-proxy-swwz8 1/1 Running 1 23h
kube-system kube-proxy-vx8lq 1/1 Running 1 23h
kube-system kube-scheduler-ip-10-0-0-187.ap-northeast-1.compute.internal 1/1 Running 2 23h
kube-system kubernetes-dashboard-7d75c474bb-4rzhj 0/1 CrashLoopBackOff 5 7h5m
-> まだ別の問題は発生中。calico-nodeがReadyにはなった。
[root@ip-10-0-0-187 manifests]# kubectl logs calico-kube-controllers-65b8787765-xldtm -n kube-system
2019-08-16 10:47:11.589 [INFO][1] main.go 92: Loaded configuration from environment config=&config.Config{LogLevel:"info", ReconcilerPeriod:"5m", CompactionPeriod:"10m", EnabledControllers:"node", WorkloadEndpointWorkers:1, ProfileWorkers:1, PolicyWorkers:1, NodeWorkers:1, Kubeconfig:"", HealthEnabled:true, SyncNodeLabels:true, DatastoreType:"kubernetes"}
2019-08-16 10:47:11.592 [INFO][1] k8s.go 228: Using Calico IPAM
W0816 10:47:11.592129 1 client_config.go:552] Neither --kubeconfig nor --master was specified. Using the inClusterConfig. This might not work.
2019-08-16 10:47:11.593 [INFO][1] main.go 113: Ensuring Calico datastore is initialized
2019-08-16 10:47:21.593 [ERROR][1] client.go 255: Error getting cluster information config ClusterInformation="default" error=Get https://10.96.0.1:443/apis/crd.projectcalico.org/v1/clusterinformations/default: context deadline exceeded
2019-08-16 10:47:21.593 [FATAL][1] main.go 118: Failed to initialize Calico datastore error=Get https://10.96.0.1:443/apis/crd.projectcalico.org/v1/clusterinformations/default: context deadline exceeded
/etc/cni/net.d/calico-kubeconfig
# Kubeconfig file for Calico CNI plugin.
apiVersion: v1
kind: Config
clusters:
- name: local
cluster:
server: https://[20.96.0.1]:443 <- 10.96を20.96にかえた
-> いろいろ問題起こったのでinitしなおした
master
kubeadm reset
kubeadm init --service-cidr=20.96.0.0/12 --pod-network-cidr=192.168.0.0/16
node
kubeadm reset
kubeadm join 10.0.0.187:6443 --token xxxx --discovery-token-ca-cert-hash sha256:xxx
-> うまくいった！！！