Ansible 笔记
Ansible 作为常见的配置管理（Configuration Management）工具，相比 chef/puppet 的优势：
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Ansible offers a simple architecture that doesn’t require special software to be installed on nodes.
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It also provides a robust set of features and built-in modules which facilitate writing automation scripts.
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使用 python 和声明式的 yaml 语法，简单易懂。
安装
参考这篇 DO 文章
安装完成后, 配置下 hosts:
xiez@xiez-Vostro-3470:~$ cat /etc/ansible/hosts
# This is the default ansible 'hosts' file.
#
# It should live in /etc/ansible/hosts
#
# - Comments begin with the '#' character
# - Blank lines are ignored
# - Groups of hosts are delimited by [header] elements
# - You can enter hostnames or ip addresses
# - A hostname/ip can be a member of multiple groups
[servers]
server1 ansible_host=10.6.2.21
server2 ansible_host=10.6.2.22
server3 ansible_host=10.6.2.23
[servers:vars]
ansible_python_interpreter=/usr/bin/python3
测试能否ping通:
xiez@xiez-Vostro-3470:~$ ansible all -m ping -u ubuntu
server3 | SUCCESS => {
"changed": false,
"ping": "pong"
}
server1 | SUCCESS => {
"changed": false,
"ping": "pong"
}
server2 | SUCCESS => {
"changed": false,
"ping": "pong"
}
常用命令 & Cheatsheet
ansible servers -a "uptime" -u ubuntu
ansible servers --become -m apt -a "name=vim state=latest" -u ubuntu
Cheatsheet: https://www.edureka.co/blog/cheatsheets/ansible-cheat-sheet-guide/
Case study 1
通过 playbook 在安装 docker
参考这篇 DO 教程
git clone https://github.com/do-community/ansible-playbooks.git
ansible-playbook playbook.yml -l server1 -u ubuntu
Case study 2
通过 playbook 在3台全新的 ubuntu18.04 系统上安装 K8S 集群
1. Edit ansible hosts
使用本地的 hosts 文件: https://github.com/xiez/ansible-playbooks/blob/master/hosts
xiez@xiez-Vostro-3470:~/dev/ansible-playbooks$ cat hosts
[servers]
server1 ansible_host=10.6.2.21
server2 ansible_host=10.6.2.22
server3 ansible_host=10.6.2.23
[servers:vars]
ansible_python_interpreter=/usr/bin/python3
2. Setup Ubuntu
2.1 新增 ubuntu 用户, 开启公钥登录, 禁用密码登录
ansible-playbook -i hosts 01-setup_ubuntu1804/playbook.yml --extra-vars "ansible_user=cyuser ansible_password=123456 ansible_sudo_pass=123456"
2.2 修改 apt 源为 aliyun
ansible-playbook -i hosts 02-ubuntu_apt_source/playbook.yml
2.3 安装 docker, 修改 pip 源为 aliyun
ansible-playbook -i hosts 03-docker_ubuntu18.04/playbook.yml
3. Install Kubernetes v1.18.0
3.1 安装依赖（kubelet, kubeadmin, kubectl）
ansible-playbook -i hosts 04-kube_deps/playbook.yml
3.2 节点额外配置（禁用swap，docker cgroupdriver改成systemd, 更改系统hostname）
ansible-playbook -i hosts 05-kube_pre_requirements/playbook.yml
3.3 配置 master node（pull kubernetes v1.18 images, kubeadmin init, 设置 flannel 网络接口插件）
ansible-playbook -i hosts 06-setup_kube_master/playbook.yml
3.4 配置 worker node（pull kubernetes v1.18 images, join cluser）
ansible-playbook -i hosts 07-setup_kube_worker/playbook.yml
3.5 测试集群节点状态
在 master 节点上执行 get node
ubuntu@master:~$ kubectl get node
NAME STATUS ROLES AGE VERSION
master Ready master 17h v1.18.0
worker1 Ready <none> 17h v1.18.0
worker2 Ready <none> 17h v1.18.0
Test nginx deploy
kubectl create deployment nginx --image=nginx
kubectl expose deploy nginx --port 80 --target-port 80 --type NodePort
kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 18h
nginx NodePort 10.102.213.64 <none> 80:30854/TCP 7m58s
Test with curl:
xiez@xiez-Vostro-3470:~/dev/ansible-playbooks$ curl http://10.6.2.21:30854/
xiez@xiez-Vostro-3470:~/dev/ansible-playbooks$ curl http://10.6.2.22:30854/
xiez@xiez-Vostro-3470:~/dev/ansible-playbooks$ curl http://10.6.2.23:30854/