Erfahren Sie, wie Sie Kubernetes unter Ubuntu installieren.
Kubernetes ist ein von Google entwickeltes Open-Source-Tool zur Container-Orchestrierung. In diesem Artikel erfahren Sie, wie Sie Kubernetes mit einem Masterknoten und einem Worker-Knoten einrichten. Stell sicher dass du hast Docker installiert sowohl auf dem Master- als auch auf dem Worker-Knoten.
Environment Details and Setup
Für die Demonstration habe ich 2 Ubuntu-Systeme, eines ist der Master-Knoten und das andere ist der Worker-Knoten. Die Konfiguration beider Server ist wie folgt.
- 2 CPUs
- Master - 4 GB RAM / Worker - 2 GB RAM
- 10 GB Festplatte
Nutzen Sie den hostnamectl Befehl zum Festlegen des Hostnamens auf beiden Systemen.
Auf dem Master-Knoten:
geekflare@geekflare:~$ sudo hostnamectl set-hostname kubernetes-masterAuf dem Arbeiterknoten:
geekflare@geekflare:~$ sudo hostnamectl set-hostname kubernetes-workerNachfolgend sind die Details beider Knoten aufgeführt.
Hauptknoten
- Hostname: kubernetes-master
- IP-Adresse: 192.168.0.107
Arbeiterknoten
- Hostname: kubernetes-worker
- IP-Adresse: 192.168.0.108
Hosts-Datei bearbeiten auf beiden Systemen.
geekflare@geekflare:~$ sudo gedit /etc/hosts
192.168.0.107 kubernetes-master
192.168.0.109 kubernetes-workerBevor Sie mit der Installation von Kubernetes beginnen, führen Sie den folgenden Befehl sowohl auf dem Master- als auch auf dem Worker-Knoten aus, um zu überprüfen, ob Docker aktiv ist.
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
Führen Sie alle in diesem Abschnitt genannten Befehle auf Master- und Worker-Knoten aus.
Fügen Sie zunächst den Kubernetes-Paket-Repository-Schlüssel hinzu.
geekflare@kubernetes-master:~$ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add
[sudo] password for geekflare:
OKFühren Sie den folgenden Befehl aus, um das Kubernetes-Paketrepository zu konfigurieren.
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... DoneDeaktivieren Sie den Swap auf beiden Knoten, bevor Sie fortfahren.
geekflare@kubernetes-master:~$ sudo swapoff -aInstall Kubeadm
Jetzt müssen Sie kubeadm installieren.
kubeadm ist ein Tool in Kubernetes, mit dem Knoten im Kubernetes-Cluster hinzugefügt werden.
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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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) ...Überprüfen Sie die kubeadm-Version, um festzustellen, ob sie korrekt installiert wurde.
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
Führen Sie nun den Befehl init aus, um den Kubernetes-Cluster nur auf dem zu initialisieren Hauptknoten. Benutzen --apiserver-advertise-address um dem Worker-Knoten die IP-Adresse des Masters mitzuteilen.
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!Um Ihren Cluster verwenden zu können, müssen Sie als regulärer Benutzer Folgendes ausführen:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/configAls Nächstes müssen Sie ein Pod-Netzwerk im Cluster bereitstellen.
Run kubectl apply -f [podnetwork].yaml mit einer der Optionen unter https://kubernetes.io/docs/concepts/cluster-administration/addons/
Anschließend können Sie einer beliebigen Anzahl von Worker-Knoten beitreten, indem Sie jeweils Folgendes als Root ausführen:
kubeadm join 192.168.0.107:6443 --token dmamk9.0nmo62mhom8961qw --discovery-token-ca-cert-hash sha256:2de92f42e84d2020d8b19b1778785df5f8196e5eedaa5664ad911e8c23f58963Erstellen Sie, wie in der obigen Ausgabe erwähnt, das Verzeichnis .kube und kopieren Sie die Datei admin.conf in die Konfigurationsdatei im Verzeichnis .kube.
geekflare@kubernetes-master:~$ 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) $HOME/.kube/configIn diesem Moment, wenn Sie die kubectl get nodes Befehl, sehen Sie den Status des Master-Knotens ist Nicht bereit.
geekflare@kubernetes-master:~$ sudo kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubernetes-master NotReady master 2m34s v1.17.0Deploy Pod Network – Flannel
Als Nächstes müssen Sie ein Pod-Netzwerk auf dem Masterknoten bereitstellen. Ich benutze das Flanell-Pod-Netzwerk. Es wird zur Kommunikation zwischen Knoten im Kubernetes-Cluster verwendet.
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 createdÜberprüfen Sie den Status des Masterknotens, er muss sich in befinden Bereit Zustand.
geekflare@kubernetes-master:~$ sudo kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubernetes-master Ready master 4m41s v1.17.0Überprüfen Sie nach einigen Sekunden, ob alle Pods betriebsbereit sind.
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
Nachdem Ihr Masterknoten ordnungsgemäß konfiguriert wurde und ausgeführt wird, müssen Sie den Worker-Knoten hinzufügen. Hier müssen Sie den Befehl join auf dem Worker-Knoten ausführen, den Sie nach der Initialisierung erhalten haben kubeadm.
Führen Sie den folgenden Befehl auf dem Worker-Knoten aus, um dem Master-Knoten beizutreten.
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.Auf dem Master-Knoten:
Nachdem der Worker-Knoten dem Cluster beigetreten ist, werden jetzt einige weitere Pods ausgeführt.
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 5m13sFühren Sie nun die aus kubectl Befehl erneut auf dem Masterknoten, um zu überprüfen, ob der Arbeitsknoten dem Cluster beigetreten ist und im Status Bereit ausgeführt wird.
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
Nachdem das Kubernetes-Setup fertig ist, können Sie mit der Orchestrierung von Containern im Kubernetes-Cluster beginnen. Wenn Kubernetes Sache Sie begeistert, möchten Sie vielleicht lernen, indem Sie dies nehmen Udemy natürlich.
