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| − | This article describes a way to deploy a Kubernetes cluster on a few CentOS 7 machines, using Docker with ploop graphdriver. | + | This article describes a way to deploy a Kubernetes cluster on a few CentOS 7 machines. |
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| | {{Stub}} | | {{Stub}} |
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| | * CentOS 7 minimal installed | | * CentOS 7 minimal installed |
| | * firewalld stopped | | * firewalld stopped |
| − | * ntpd installed and running
| + | : <code>systemctl stop firewalld; systemctl disable firewalld</code> |
| − | | + | * ntpd installed and running: |
| − | For Docker to work with ploop (on the nodes), you also need:
| + | : <code>yum -y install ntpd && systemctl start ntpd && systemctl enable ntpd</code> |
| − | * ext4 filesystem on /var/lib
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| − | * vzkernel installed and booted into
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| − | * ploop installed
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| − | * docker with ploop graphdriver installed
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| − | | |
| − | == CentOS 7 installation ==
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| − | | |
| − | 1. Select "disk", "manual setup", "standard partitioning", "automatically create partitions", then change xfs to ext4 for / and /boot.
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| − | | |
| − | 2. After reboot, login and edit <code>/etc/sysconfig/network-scripts/ifcfg-eth0</code> file, making sure it has the following line:
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| − | ONBOOT=yes
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| − | | |
| − | 3. Enable networking:
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| − | ifup eth0
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| − | | |
| − | 4. Update the system:
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| − | yum update -y
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| − | | |
| − | 5. Disable firewalld:
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| − | systemctl stop firewalld; systemctl disable firewalld
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| − | | |
| − | 6. Install and enable ntpd:
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| − | yum -y install ntp && systemctl start ntpd && systemctl enable ntpd
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| − | | |
| | | | |
| | == Master installation == | | == Master installation == |
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| | Make sure <code>/etc/kubernetes/apiserver</code> contains this: | | Make sure <code>/etc/kubernetes/apiserver</code> contains this: |
| | | | |
| − | === Start master node services ===
| + | 4. Start master node services: |
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| | for S in etcd kube-apiserver kube-controller-manager kube-scheduler; do | | for S in etcd kube-apiserver kube-controller-manager kube-scheduler; do |
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| | == Set nodes (minions) == | | == Set nodes (minions) == |
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| − | === Set the node hostname ===
| + | 1. Install vzkernel: |
| − | | |
| − | For example:
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| − | echo kube-node2 > /etc/hostname
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| − | | |
| − | === Install vzkernel ===
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| − | | |
| − | This is needed for ploop to work. If you don't need ploop, you can skip this step.
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| − | | |
| − | First, install vzkernel:
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| | rpm -ihv https://download.openvz.org/virtuozzo/factory/x86_64/os/Packages/v/vzkernel-3.10.0-229.7.2.vz7.6.9.x86_64.rpm | | rpm -ihv https://download.openvz.org/virtuozzo/factory/x86_64/os/Packages/v/vzkernel-3.10.0-229.7.2.vz7.6.9.x86_64.rpm |
| | | | |
| − | Or, use the latest vzkernel from https://download.openvz.org/virtuozzo/factory/x86_64/os/Packages/v/
| + | 2. Enable docker-ploop repo: |
| − | | |
| − | Then reboot into vzkernel:
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| − | reboot
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| − | | |
| − | Finally, make sure vzkernel is running:
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| − | uname -r
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| − | 3.10.0-229.7.2.vz7.6.9
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| − | | |
| − | === Install docker with ploop graphdriver ===
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| | | | |
| − | This is needed for ploop to work. If you don't need ploop, you can skip this step.
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| − |
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| − | First, install docker and ploop:
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| − | yum install -y wget
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| | cd /etc/yum.repos.d/ | | cd /etc/yum.repos.d/ |
| | wget https://copr.fedoraproject.org/coprs/kir/docker-ploop/repo/epel-7/kir-docker-ploop-epel-7.repo | | wget https://copr.fedoraproject.org/coprs/kir/docker-ploop/repo/epel-7/kir-docker-ploop-epel-7.repo |
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| | yum install ploop docker | | yum install ploop docker |
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| − | Then, set ploop driver to be default for docker. Make sure <code>/etc/sysconfig/docker-storage</code> contains:
| + | 3. Set ploop driver to be default for docker. |
| | + | |
| | + | Make sure <code>/etc/sysconfig/docker-storage</code> contains: |
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| | DOCKER_STORAGE_OPTIONS="-s ploop" | | DOCKER_STORAGE_OPTIONS="-s ploop" |
| | | | |
| − | === Install flannel and kubernetes-node ===
| + | 4. Install flannel and kubernetes-node: |
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| | yum -y install flannel kubernetes-node | | yum -y install flannel kubernetes-node |
| − |
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| − | === Configure flannel for master etcd ===
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| − |
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| − | Update the following line in /etc/sysconfig/flanneld to make sure it contains master IP:
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| − |
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| − | FLANNEL_ETCD="http://192.168.122.211:2379"
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| − |
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| − | === Configure Kubernetes for master node ===
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| − |
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| − | Update the following line in /etc/kubernetes/config to make sure in contains master IP:
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| − |
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| − | KUBE_MASTER="--master=http://192.168.122.211:8080"
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| − |
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| − | === Configure kubelet ===
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| − |
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| − | In /etc/kubelet/config:
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| − |
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| − | 1. Enable it to listen on all interfaces:
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| − | KUBELET_ADDRESS="--address=0.0.0.0"
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| − |
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| − | 2. Comment out this line to use default hostname:
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| − | # KUBELET_HOSTNAME
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| − |
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| − | 3. Make sure this points to master node IP:
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| − | KUBELET_API_SERVER="--api_servers=http://192.168.122.211:8080"
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| − |
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| − | === Start needed services ===
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| − |
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| − | Start needed services:
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| − | systemctl restart docker
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| − | systemctl restart flanneld
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| − | systemctl restart kubelet
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| − | systemctl restart kube-proxy
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| − |
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| − | NOTE: if 'systemctl restart docker' fails, you might need to run:
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| − | systemctl stop docker
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| − | ip l del docker0
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| − |
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| − | Enable needed services:
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| − | systemctl enable docker
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| − | systemctl enable flanneld
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| − | systemctl enable kubelet
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| − | systemctl enable kube-proxy
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| − |
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| − | == Checking that the system is set up ==
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| − |
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| − | On the master node, check that the needed services are running:
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| − | for S in etcd kube-apiserver kube-controller-manager kube-scheduler; do
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| − | systemctl status $S
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| − | done
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| − |
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| − | On the nodes, check that the needed services are running:
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| − | systemctl status docker
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| − | systemctl status flanneld
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| − | systemctl status kubelet
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| − | systemctl status kube-proxy
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| − |
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| − | Finally, check that the nodes are visible and active:
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| − | # kubectl get nodes
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| − | NAME LABELS STATUS
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| − | kube-node1 kubernetes.io/hostname=kube-node1 Ready
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| − | kube-node2 kubernetes.io/hostname=kube-node2 Ready
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| − |
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| − | NOTE: if there are some stale nodes listed, you can remove those:
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| − | kubectl delete node localhost.localdomain
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| | == See also == | | == See also == |
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| | * [https://github.com/coreos/etcd/blob/master/Documentation/configuration.md etcd configuration] | | * [https://github.com/coreos/etcd/blob/master/Documentation/configuration.md etcd configuration] |
