Apprenez à installer Kubernetes sur Ubuntu.
Kubernetes est un outil d'orchestration de conteneurs open source développé par Google. Dans cet article, vous apprendrez à configurer Kubernetes avec un nœud maître et un nœud worker. Assurez-vous que vous avez Docker installé sur le nœud maître et travailleur.
Environment Details and Setup
Pour la démonstration, j'ai 2 systèmes Ubuntu, l'un sera le nœud maître et l'autre sera le nœud worker. La configuration des deux serveurs est la suivante.
- 2 CPU
- Maître - 4 Go de RAM / Worker - 2 Go de RAM
- Disque dur de 10 Go
Utilisez hostnamectl commande pour définir le nom d'hôte sur les deux systèmes.
Sur le nœud maître:
geekflare@geekflare:~$ sudo hostnamectl set-hostname kubernetes-masterSur le nœud de travail:
geekflare@geekflare:~$ sudo hostnamectl set-hostname kubernetes-workerVoici donc les détails des deux nœuds.
Nœud maître
- Nom d'hôte: kubernetes-master
- Adresse IP: 192.168.0.107
Nœud de travail
- Nom d'hôte: kubernetes-worker
- Adresse IP: 192.168.0.108
Modifier le fichier hosts sur les deux systèmes.
geekflare@geekflare:~$ sudo gedit /etc/hosts
192.168.0.107 kubernetes-master
192.168.0.109 kubernetes-workerAvant de commencer à installer Kubernetes, exécutez la commande ci-dessous sur les nœuds maître et de travail pour vérifier si Docker est opérationnel.
geekflare@geekflare:~$ sudo service docker status
[sudo] password for geekflare:
● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running) since Sat 2019-11-23 15:39:36 EST; 3 weeks 0 days ago
Docs: https://docs.docker.com
Main PID: 8840 (dockerd)
Tasks: 17
Memory: 42.3M
CGroup: /system.slice/docker.service
└─8840 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
Nov 23 15:39:35 geekflare dockerd[8840]: time="2019-11-23T15:39:35.091941184-05:00" level=warning msg="Your kernel does not support cgrou
Nov 23 15:39:35 geekflare dockerd[8840]: time="2019-11-23T15:39:35.093149218-05:00" level=info msg="Loading containers: start."
Nov 23 15:39:35 geekflare dockerd[8840]: time="2019-11-23T15:39:35.957842188-05:00" level=info msg="Default bridge (docker0) is assigned
Nov 23 15:39:36 geekflare dockerd[8840]: time="2019-11-23T15:39:36.078753190-05:00" level=info msg="Loading containers: done."
Nov 23 15:39:36 geekflare dockerd[8840]: time="2019-11-23T15:39:36.664727326-05:00" level=info msg="Docker daemon" commit=481bc77 graphdr
Nov 23 15:39:36 geekflare dockerd[8840]: time="2019-11-23T15:39:36.817929464-05:00" level=error msg="cluster exited with error: error whi
Nov 23 15:39:36 geekflare dockerd[8840]: time="2019-11-23T15:39:36.820439024-05:00" level=error msg="swarm component could not be started
Nov 23 15:39:36 geekflare dockerd[8840]: time="2019-11-23T15:39:36.820821712-05:00" level=info msg="Daemon has completed initialization"
Nov 23 15:39:36 geekflare systemd[1]: Started Docker Application Container Engine.
Nov 23 15:39:36 geekflare dockerd[8840]: time="2019-11-23T15:39:36.883382952-05:00" level=info msg="API listen on /home/geekflare/docker.sock
lines 1-20/20 (END)Install Kubernetes
Exécutez toutes les commandes mentionnées dans cette section sur les nœuds maître et worker.
Tout d'abord, ajoutez la clé de référentiel du package Kubernetes.
geekflare@kubernetes-master:~$ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add
[sudo] password for geekflare:
OKExécutez la commande ci-dessous pour configurer le référentiel de packages Kubernetes.
geekflare@kubernetes-master:~$ sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"
Hit:1 https://download.docker.com/linux/ubuntu bionic InRelease
Hit:2 http://ppa.launchpad.net/ansible/ansible/ubuntu cosmic InRelease
Get:3 http://apt.puppetlabs.com bionic InRelease [85.3 kB]
Hit:5 http://security.ubuntu.com/ubuntu cosmic-security InRelease
Hit:6 http://us.archive.ubuntu.com/ubuntu cosmic InRelease
Ign:7 http://pkg.jenkins.io/debian-stable binary/ InRelease
Hit:8 http://us.archive.ubuntu.com/ubuntu cosmic-updates InRelease
Hit:9 http://pkg.jenkins.io/debian-stable binary/ Release
Hit:10 http://us.archive.ubuntu.com/ubuntu cosmic-backports InRelease
Get:4 https://packages.cloud.google.com/apt kubernetes-xenial InRelease [8,993 B]
Get:11 http://apt.puppetlabs.com bionic/puppet6 amd64 Packages [36.1 kB]
Get:13 https://packages.cloud.google.com/apt kubernetes-xenial/main amd64 Packages [32.2 kB]
Fetched 163 kB in 3s (49.1 kB/s)
Reading package lists... DoneAvant de continuer, désactivez le swap sur les deux nœuds.
geekflare@kubernetes-master:~$ sudo swapoff -aInstall Kubeadm
Vous devez maintenant installer kubeadm.
kubeadm est un outil dans Kubernetes qui est utilisé pour ajouter des nœuds dans le cluster Kubernetes.
geekflare@kubernetes-master:~$ sudo apt-get install kubeadm -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
conntrack cri-tools ebtables ethtool kubectl kubelet kubernetes-cni socat
The following NEW packages will be installed:
conntrack cri-tools ebtables ethtool kubeadm kubectl kubelet kubernetes-cni socat
0 upgraded, 9 newly installed, 0 to remove and 235 not upgraded.
Need to get 51.8 MB of archives.
After this operation, 273 MB of additional disk space will be used.
Get:3 http://us.archive.ubuntu.com/ubuntu cosmic/main amd64 conntrack amd64 1:1.4.5-1 [30.2 kB]
Get:1 https://packages.cloud.google.com/apt kubernetes-xenial/main amd64 cri-tools amd64 1.13.0-00 [8,776 kB]
Get:6 http://us.archive.ubuntu.com/ubuntu cosmic/main amd64 ebtables amd64 2.0.10.4-3.5ubuntu5 [79.8 kB]
Get:8 http://us.archive.ubuntu.com/ubuntu cosmic/main amd64 ethtool amd64 1:4.16-1 [115 kB]
Get:9 http://us.archive.ubuntu.com/ubuntu cosmic/main amd64 socat amd64 1.7.3.2-2ubuntu2 [342 kB]
Get:2 https://packages.cloud.google.com/apt kubernetes-xenial/main amd64 kubernetes-cni amd64 0.7.5-00 [6,473 kB]
Get:4 https://packages.cloud.google.com/apt kubernetes-xenial/main amd64 kubelet amd64 1.17.0-00 [19.2 MB]
Get:5 https://packages.cloud.google.com/apt kubernetes-xenial/main amd64 kubectl amd64 1.17.0-00 [8,742 kB]
Get:7 https://packages.cloud.google.com/apt kubernetes-xenial/main amd64 kubeadm amd64 1.17.0-00 [8,059 kB]
Fetched 51.8 MB in 8s (6,419 kB/s)
Selecting previously unselected package conntrack.
(Reading database ... 318151 files and directories currently installed.)
Preparing to unpack .../0-conntrack_1%3a1.4.5-1_amd64.deb ...
Unpacking conntrack (1:1.4.5-1) ...
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Preparing to unpack .../3-ethtool_1%3a4.16-1_amd64.deb ...
Unpacking ethtool (1:4.16-1) ...
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Unpacking kubeadm (1.17.0-00) ...
Setting up conntrack (1:1.4.5-1) ...
Setting up kubernetes-cni (0.7.5-00) ...
Setting up cri-tools (1.13.0-00) ...
Setting up socat (1.7.3.2-2ubuntu2) ...
Processing triggers for systemd (239-7ubuntu10.12) ...
Setting up ebtables (2.0.10.4-3.5ubuntu5) ...
Created symlink /etc/systemd/system/multi-user.target.wants/ebtables.service → /lib/systemd/system/ebtables.service.
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
Setting up kubectl (1.17.0-00) ...
Processing triggers for man-db (2.8.4-2) ...
Setting up ethtool (1:4.16-1) ...
Setting up kubelet (1.17.0-00) ...
Created symlink /etc/systemd/system/multi-user.target.wants/kubelet.service → /lib/systemd/system/kubelet.service.
Setting up kubeadm (1.17.0-00) ...
Processing triggers for systemd (239-7ubuntu10.12) ...Vérifiez la version de kubeadm pour vérifier si elle a été installée correctement.
geekflare@kubernetes-master:~$ kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.0", GitCommit:"70132b0f130acc0bed193d9ba59dd186f0e634cf", GitTreeState:"clean", BuildDate:"2019-12-07T21:17:50Z", GoVersion:"go1.13.4", Compiler:"gc", Platform:"linux/amd64"}Initialize Kubernetes Cluster
Maintenant, exécutez la commande init pour initialiser le cluster Kubernetes uniquement sur le noeud maître. utilisation --apiserver-advertise-address pour informer le nœud worker de l'adresse IP du maître.
geekflare@kubernetes-master:~$ sudo kubeadm init --apiserver-advertise-address=192.168.0.107 --pod-network-cidr=10.244.0.0/16
W1217 11:05:15.474854 10193 validation.go:28] Cannot validate kube-proxy config - no validator is available
W1217 11:05:15.474935 10193 validation.go:28] Cannot validate kubelet config - no validator is available
[init] Using Kubernetes version: v1.17.0
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [kubernetes-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.0.107]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [kubernetes-master localhost] and IPs [192.168.0.107 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [kubernetes-master localhost] and IPs [192.168.0.107 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
W1217 11:05:25.584769 10193 manifests.go:214] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W1217 11:05:25.587128 10193 manifests.go:214] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 35.010368 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.17" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node kubernetes-master as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node kubernetes-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: dmamk9.0nmo62mhom8961qw
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
Your Kubernetes control-plane has initialized successfully!Pour commencer à utiliser votre cluster, vous devez exécuter ce qui suit en tant qu'utilisateur régulier:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/configEnsuite, vous devez déployer un réseau de pod sur le cluster.
cours kubectl apply -f [podnetwork].yaml avec l'une des options répertoriées sur https://kubernetes.io/docs/concepts/cluster-administration/addons/
Ensuite, vous pouvez rejoindre n'importe quel nombre de nœuds de travail en exécutant ce qui suit sur chacun en tant que root:
kubeadm join 192.168.0.107:6443 --token dmamk9.0nmo62mhom8961qw --discovery-token-ca-cert-hash sha256:2de92f42e84d2020d8b19b1778785df5f8196e5eedaa5664ad911e8c23f58963Comme mentionné dans la sortie ci-dessus, créez le répertoire .kube et copiez le fichier admin.conf dans le fichier de configuration du répertoire .kube.
geekflare@kubernetes-master:~$ mkdir -p $HOME/.kube
geekflare@kubernetes-master:~$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
geekflare@kubernetes-master:~$ sudo chown $(id -u):$(id -g) $HOME/.kube/configÀ ce moment, lorsque vous exécutez le kubectl get nodes commande, vous verrez que l'état du nœud maître est Pas prêt.
geekflare@kubernetes-master:~$ sudo kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubernetes-master NotReady master 2m34s v1.17.0Deploy Pod Network – Flannel
Ensuite, vous devez déployer un réseau de pod sur le nœud maître. J'utilise le réseau de capsules Flannel. Il est utilisé pour communiquer entre les nœuds du cluster Kubernetes.
geekflare@kubernetes-master:~$ sudo kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds-amd64 created
daemonset.apps/kube-flannel-ds-arm64 created
daemonset.apps/kube-flannel-ds-arm created
daemonset.apps/kube-flannel-ds-ppc64le created
daemonset.apps/kube-flannel-ds-s390x createdVérifiez l'état du nœud maître, il doit être Prêt à fonctionner Etat.
geekflare@kubernetes-master:~$ sudo kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubernetes-master Ready master 4m41s v1.17.0Après quelques secondes, vérifiez si tous les pods sont opérationnels.
geekflare@kubernetes-master:~$ kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-6955765f44-rzw9d 1/1 Running 0 4m17s
kube-system coredns-6955765f44-xvgdp 1/1 Running 0 4m17s
kube-system etcd-kubernetes-master 1/1 Running 0 4m27s
kube-system kube-apiserver-kubernetes-master 1/1 Running 0 4m27s
kube-system kube-controller-manager-kubernetes-master 1/1 Running 0 4m27s
kube-system kube-flannel-ds-amd64-c2rf5 1/1 Running 0 81s
kube-system kube-proxy-mvdd7 1/1 Running 0 4m17s
kube-system kube-scheduler-kubernetes-master 1/1 Running 0 4m27sAdd Worker Node to the Cluster
Maintenant que votre nœud maître est correctement configuré et en cours d'exécution, il est temps d'ajouter le nœud worker. Ici, vous devez exécuter la commande join sur le nœud worker, que vous avez obtenue après l'initialisation kubeadm.
Exécutez la commande ci-dessous sur le nœud worker pour rejoindre le nœud maître.
geekflare@kubernetes-worker:~$ sudo kubeadm join 192.168.0.107:6443 --token dmamk9.0nmo62mhom8961qw --discovery-token-ca-cert-hash sha256:2de92f42e84d2020d8b19b1778785df5f8196e5eedaa5664ad911e8c23f58963
[sudo] password for geekflare:
W1217 11:08:01.066191 28968 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.17" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.Sur le nœud maître:
Vous verrez quelques pods supplémentaires en cours d'exécution maintenant après que le nœud worker a rejoint le cluster.
geekflare@kubernetes-master:~$ kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-6955765f44-9c7jc 1/1 Running 0 5m3s
kube-system coredns-6955765f44-c9s9r 1/1 Running 0 5m3s
kube-system etcd-kubernetes-master 1/1 Running 0 5m12s
kube-system kube-apiserver-kubernetes-master 1/1 Running 0 5m12s
kube-system kube-controller-manager-kubernetes-master 1/1 Running 0 5m13s
kube-system kube-flannel-ds-amd64-lgr62 1/1 Running 0 3m35s
kube-system kube-flannel-ds-amd64-n6vwm 1/1 Running 0 27s
kube-system kube-proxy-9mqp6 1/1 Running 0 27s
kube-system kube-proxy-kwkz2 1/1 Running 0 5m3s
kube-system kube-scheduler-kubernetes-master 1/1 Running 0 5m13sMaintenant, exécutez le kubectl à nouveau sur le nœud maître pour vérifier si le nœud de travail a rejoint le cluster et s’exécute à l’état Prêt.
geekflare@kubernetes-master:~$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubernetes-master Ready master 5m27s v1.17.0
kubernetes-worker Ready <none> 31s v1.17.0Conclusion
Maintenant que la configuration de Kubernetes est prête, vous pouvez commencer à orchestrer des conteneurs sur le cluster Kubernetes. Si le truc Kubernetes vous excite, vous voudrez peut-être apprendre en prenant ceci Cours Udemy.
