How to using kubespray

juner
juner

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kubespray github

Advantages

  • available for aws, ace, azure, openstack or bare metal
  • available HA cluster
  • can chose the network plugin
  • 인기있는 linux 배포판 지원

requirements

  • Support OS :
    • core os
    • debian jessie
    • ubuntu <= 16.04
    • centos/rhel <= 7

versions - 컴포넌트 버전

  • kubernetes <= 1.6.4
  • etc 3.0.17
  • flannels 0.6.2
  • calicoctl 0.23.0
  • canal calico/flannel 버전과 동일
  • weave 1.8.2
  • docker 1.13.1
  • rat 1.21.0

prerequisite - 필수조건

  • ansible은 2.3이상
  • python-netaddr은 설치되어있어야 함
  • ninja 2.9 이상 필요함
  • target server는 인터넷이 되고 ipv4 forwarding이 되어야 함
  • ssh key는 인벤토리에 복사되어야 함

supported network plugin

  • flannel
  • calico
  • canal
  • weave

Install a kubernetes cluster using kubespray - 설치

install a ansible

$ sudo apt-get install ansible
$ ansible --version
ansible 2.3.1.0
  config file = /etc/ansible/ansible.cfg
    configured module search path = [u'/usr/share/ansible']
      python version = 2.7.6 (default, Oct 26 2016, 20:30:19) [GCC 4.8.4]
$ sudo apt-get install python-netaddr

clone a kubespray git repo

$ git clone https://github.com/kubernetes-incubator/kubespray.git

$ cd kubespray
$ cp -r inventory myinventory
$ ips=(host248 host173 host183 host153)
$ CONFIG_FILE=myinventory/inventory.cfg python3 contrib/inventory_builder/inventory.py ${ips[@]}
    DEBUG: Adding group all
    DEBUG: Adding group kube-master
    DEBUG: Adding group kube-node
    DEBUG: Adding group etcd
    DEBUG: Adding group k8s-cluster:children
    DEBUG: Adding group calico-rr
    DEBUG: adding host node1 to group all
    DEBUG: adding host node2 to group all
    DEBUG: adding host node3 to group all
    DEBUG: adding host node4 to group all
    DEBUG: adding host kube-node to group k8s-cluster:children
    DEBUG: adding host kube-master to group k8s-cluster:children
    DEBUG: adding host node1 to group etcd
    DEBUG: adding host node2 to group etcd
    DEBUG: adding host node3 to group etcd
    DEBUG: adding host node1 to group kube-master
    DEBUG: adding host node2 to group kube-master
    DEBUG: adding host node1 to group kube-node
    DEBUG: adding host node2 to group kube-node
    DEBUG: adding host node3 to group kube-node
    DEBUG: adding host node4 to group kube-node

check the inventory.cfg generated by inventory.py

$ vi inventory/inventory.cfg
[kube-master]
node1
node2

[etcd]
node1
node2
node3

[kube-node]
node2
node3
node4
node1

[k8s-cluster:children]
kube-node
kube-master

[all]
node1    ansible_host=host248 ip=172.10.30.248
node2    ansible_host=host173 ip=172.10.30.173
node3    ansible_host=host183 ip=172.10.30.183
node4    ansible_host=host153 ip=172.10.30.153

run cluster.yml playbook

$ ansible-playbook -i myinventory/inventory.cfg cluster.yml -b -v --private-key=~/k8s-dev.pem
...


ubuntu@host248:~$ kubectl cluster-info
Kubernetes master is running at http://localhost:8080
KubeDNS is running at http://localhost:8080/api/v1/proxy/namespaces/kube-system/services/kube-dns   

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

ubuntu@host248:~$ kubectl get cs
NAME                 STATUS    MESSAGE              ERROR
controller-manager   Healthy   ok
scheduler            Healthy   ok
etcd-2               Healthy   {"health": "true"}
etcd-0               Healthy   {"health": "true"}
etcd-1               Healthy   {"health": "true"}

ubuntu@host248:~$ kubectl get pod --all-namespaces
NAMESPACE     NAME                                       READY     STATUS    RESTARTS   AGE
kube-system   flannel-ip-host153                   1/1       Running   1          1d
kube-system   flannel-ip-host183                   1/1       Running   1          1d
kube-system   flannel-ip-host248                   1/1       Running   1          1d
kube-system   flannel-ip-host173                   1/1       Running   1          1d
kube-system   kube-apiserver-ip-host248            1/1       Running   0          1d
kube-system   kube-apiserver-ip-host173            1/1       Running   0          1d
kube-system   kube-controller-manager-ip-host248   1/1       Running   1          1d
kube-system   kube-controller-manager-ip-host173   1/1       Running   1          1d
kube-system   kube-dns-3841192733-vf5xm                  3/3       Running   0          1d
kube-system   kube-dns-3841192733-xm1xr                  3/3       Running   0          1d
kube-system   kube-proxy-ip-host153                1/1       Running   1          1d
kube-system   kube-proxy-ip-host183                1/1       Running   1          1d
kube-system   kube-proxy-ip-host248                1/1       Running   1          1d
kube-system   kube-proxy-ip-host173                1/1       Running   1          1d
kube-system   kube-scheduler-ip-host248            1/1       Running   0          1d
kube-system   kube-scheduler-ip-host173            1/1       Running   0          1d
kube-system   kubedns-autoscaler-1833630871-x52k5        1/1       Running   0          1d
kube-system   nginx-proxy-ip-host153               1/1       Running   1          1d
kube-system   nginx-proxy-ip-host183               1/1       Running   1          1d

pros and cons for me

장점

  • sensible-playbook을 이용한 설치로 안정적이고 편리함
  • 클러스터 생성/확장 모든 내용 지원가능
  • master ha 지원함
  • 모든 플랫폼(public/private/baremetal) 지원가능

단점

  • 아직 인큐베이팅 프로젝트이므로 어떻게 될지 모름
  • 우리에 맞게 사용하려면 수정이 필요할 것으로 예상됨
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