Ansible是一款優秀的自動化IT運維工具，具有遠程安裝、遠程部署應用、遠程管理能力，支持Windows、Linux、Unix、macOS和大型機等多種操作系統。 這篇隨筆以CentOS 7.6為主機操作系統，演示Ansible工具的安裝過程，將一個本地應用例子安裝到遠程主機，併在遠程主機上運行應... ...
前言
Ansible是一款優秀的自動化IT運維工具，具有遠程安裝、遠程部署應用、遠程管理能力，支持Windows、Linux、Unix、macOS和大型機等多種操作系統。
下麵就以CentOS 7.6為主機操作系統，演示安裝Ansible工具的過程，將一個本地應用例子安裝到遠程主機，併在遠程主機上運行應用。
一、環境準備
完成這個例子，最少需要兩台主機，一臺安裝Ansible運維工具本身，用作管理主機，一臺用作遠程目標主機。
兩台主機都預先安裝了CentOS 7.6操作系統。
# Ansible管理主機
192.168.6.190 root@k3s-vip
# 遠程目標主機
192.168.6.193 root@k3s-node3
二、安裝Ansible運維工具
使用SSH登錄到擬安裝Ansible的主機。
- 查看系統環境：
[root@k3s-vip ~]# uname -a Linux k3s-vip 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
- 運行安裝命令
Ansible的安裝過程很簡單，只需要一條yum命令。
使用CentOS自帶工具yum自動下載、安裝Ansible。Ansible依賴於Python語言，安裝Ansible時會自動下載、安裝Python語言包。
安裝過程中會提示是否安裝依賴軟體包，全部選y。
[root@k3s-vip ~]# yum install ansible Loaded plugins: fastestmirror, langpacks Determining fastest mirrors * base: centos.ustc.edu.cn * extras: mirrors.cqu.edu.cn * updates: mirrors.cqu.edu.cn base | 3.6 kB 00:00:00 extras | 3.4 kB 00:00:00 updates | 3.4 kB 00:00:00 (1/2): extras/7/x86_64/primary_db | 187 kB 00:00:01 (2/2): updates/7/x86_64/primary_db | 3.4 MB 00:00:15 Resolving Dependencies --> Running transaction check ---> Package ansible.noarch 0:2.4.2.0-2.el7 will be installed --> Processing Dependency: sshpass for package: ansible-2.4.2.0-2.el7.noarch --> Processing Dependency: python2-jmespath for package: ansible-2.4.2.0-2.el7.noarch --> Processing Dependency: python-passlib for package: ansible-2.4.2.0-2.el7.noarch --> Processing Dependency: python-paramiko for package: ansible-2.4.2.0-2.el7.noarch --> Processing Dependency: python-jinja2 for package: ansible-2.4.2.0-2.el7.noarch --> Processing Dependency: python-httplib2 for package: ansible-2.4.2.0-2.el7.noarch --> Processing Dependency: python-cryptography for package: ansible-2.4.2.0-2.el7.noarch --> Running transaction check ---> Package python-httplib2.noarch 0:0.9.2-1.el7 will be installed ---> Package python-jinja2.noarch 0:2.7.2-2.el7 will be installed --> Processing Dependency: python-babel >= 0.8 for package: python-jinja2-2.7.2-2.el7.noarch --> Processing Dependency: python-markupsafe for package: python-jinja2-2.7.2-2.el7.noarch ---> Package python-paramiko.noarch 0:2.1.1-9.el7 will be installed --> Processing Dependency: python2-pyasn1 for package: python-paramiko-2.1.1-9.el7.noarch ---> Package python-passlib.noarch 0:1.6.5-2.el7 will be installed ---> Package python2-cryptography.x86_64 0:1.7.2-2.el7 will be installed --> Processing Dependency: python-idna >= 2.0 for package: python2-cryptography-1.7.2-2.el7.x86_64 --> Processing Dependency: python-cffi >= 1.4.1 for package: python2-cryptography-1.7.2-2.el7.x86_64 --> Processing Dependency: python-enum34 for package: python2-cryptography-1.7.2-2.el7.x86_64 ---> Package python2-jmespath.noarch 0:0.9.0-3.el7 will be installed ---> Package sshpass.x86_64 0:1.06-2.el7 will be installed --> Running transaction check ---> Package python-babel.noarch 0:0.9.6-8.el7 will be installed ---> Package python-cffi.x86_64 0:1.6.0-5.el7 will be installed --> Processing Dependency: python-pycparser for package: python-cffi-1.6.0-5.el7.x86_64 ---> Package python-enum34.noarch 0:1.0.4-1.el7 will be installed ---> Package python-idna.noarch 0:2.4-1.el7 will be installed ---> Package python-markupsafe.x86_64 0:0.11-10.el7 will be installed ---> Package python2-pyasn1.noarch 0:0.1.9-7.el7 will be installed --> Running transaction check ---> Package python-pycparser.noarch 0:2.14-1.el7 will be installed --> Processing Dependency: python-ply for package: python-pycparser-2.14-1.el7.noarch --> Running transaction check ---> Package python-ply.noarch 0:3.4-11.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ============================================================================================================================================================================================================== Package Arch Version Repository Size ============================================================================================================================================================================================================== Installing: ansible noarch 2.4.2.0-2.el7 extras 7.6 M Installing for dependencies: python-babel noarch 0.9.6-8.el7 base 1.4 M python-cffi x86_64 1.6.0-5.el7 base 218 k python-enum34 noarch 1.0.4-1.el7 base 52 k python-httplib2 noarch 0.9.2-1.el7 extras 115 k python-idna noarch 2.4-1.el7 base 94 k python-jinja2 noarch 2.7.2-2.el7 base 515 k python-markupsafe x86_64 0.11-10.el7 base 25 k python-paramiko noarch 2.1.1-9.el7 updates 269 k python-passlib noarch 1.6.5-2.el7 extras 488 k python-ply noarch 3.4-11.el7 base 123 k python-pycparser noarch 2.14-1.el7 base 104 k python2-cryptography x86_64 1.7.2-2.el7 base 502 k python2-jmespath noarch 0.9.0-3.el7 extras 39 k python2-pyasn1 noarch 0.1.9-7.el7 base 100 k sshpass x86_64 1.06-2.el7 extras 21 k Transaction Summary ============================================================================================================================================================================================================== Install 1 Package (+15 Dependent packages) Total download size: 12 M Installed size: 57 M Is this ok [y/d/N]: y Downloading packages: warning: /var/cache/yum/x86_64/7/base/packages/python-babel-0.9.6-8.el7.noarch.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY ] 0.0 B/s | 574 kB --:--:-- ETA Public key for python-babel-0.9.6-8.el7.noarch.rpm is not installed (1/16): python-babel-0.9.6-8.el7.noarch.rpm | 1.4 MB 00:00:00 (2/16): python-idna-2.4-1.el7.noarch.rpm | 94 kB 00:00:00 (3/16): python-enum34-1.0.4-1.el7.noarch.rpm | 52 kB 00:00:00 Public key for python-httplib2-0.9.2-1.el7.noarch.rpm is not installed 13% [==========- ] 1.5 MB/s | 1.6 MB 00:00:06 ETA (4/16): python-httplib2-0.9.2-1.el7.noarch.rpm | 115 kB 00:00:00 (5/16): python-jinja2-2.7.2-2.el7.noarch.rpm | 515 kB 00:00:00 (6/16): python-passlib-1.6.5-2.el7.noarch.rpm | 488 kB 00:00:00 Public key for python-paramiko-2.1.1-9.el7.noarch.rpm is not installed (7/16): python-paramiko-2.1.1-9.el7.noarch.rpm | 269 kB 00:00:00 (8/16): python-ply-3.4-11.el7.noarch.rpm | 123 kB 00:00:00 (9/16): python-pycparser-2.14-1.el7.noarch.rpm | 104 kB 00:00:00 (10/16): python2-cryptography-1.7.2-2.el7.x86_64.rpm | 502 kB 00:00:00 (11/16): python2-pyasn1-0.1.9-7.el7.noarch.rpm | 100 kB 00:00:00 (12/16): python2-jmespath-0.9.0-3.el7.noarch.rpm | 39 kB 00:00:00 (13/16): sshpass-1.06-2.el7.x86_64.rpm | 21 kB 00:00:00 (14/16): ansible-2.4.2.0-2.el7.noarch.rpm | 7.6 MB 00:00:03 (15/16): python-cffi-1.6.0-5.el7.x86_64.rpm | 218 kB 00:00:04 (16/16): python-markupsafe-0.11-10.el7.x86_64.rpm | 25 kB 00:00:04 -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Total 1.8 MB/s | 12 MB 00:00:06 Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 Importing GPG key 0xF4A80EB5: Userid : "CentOS-7 Key (CentOS 7 Official Signing Key) <[email protected]>" Fingerprint: 6341 ab27 53d7 8a78 a7c2 7bb1 24c6 a8a7 f4a8 0eb5 Package : centos-release-7-6.1810.2.el7.centos.x86_64 (@anaconda) From : /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 Is this ok [y/N]: y Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : python2-pyasn1-0.1.9-7.el7.noarch 1/16 Installing : python-enum34-1.0.4-1.el7.noarch 2/16 Installing : python-httplib2-0.9.2-1.el7.noarch 3/16 Installing : sshpass-1.06-2.el7.x86_64 4/16 Installing : python-babel-0.9.6-8.el7.noarch 5/16 Installing : python2-jmespath-0.9.0-3.el7.noarch 6/16 Installing : python-passlib-1.6.5-2.el7.noarch 7/16 Installing : python-ply-3.4-11.el7.noarch 8/16 Installing : python-pycparser-2.14-1.el7.noarch 9/16 Installing : python-cffi-1.6.0-5.el7.x86_64 10/16 Installing : python-markupsafe-0.11-10.el7.x86_64 11/16 Installing : python-jinja2-2.7.2-2.el7.noarch 12/16 Installing : python-idna-2.4-1.el7.noarch 13/16 Installing : python2-cryptography-1.7.2-2.el7.x86_64 14/16 Installing : python-paramiko-2.1.1-9.el7.noarch 15/16 Installing : ansible-2.4.2.0-2.el7.noarch 16/16 Verifying : python-idna-2.4-1.el7.noarch 1/16 Verifying : python-markupsafe-0.11-10.el7.x86_64 2/16 Verifying : python-jinja2-2.7.2-2.el7.noarch 3/16 Verifying : python-ply-3.4-11.el7.noarch 4/16 Verifying : python-passlib-1.6.5-2.el7.noarch 5/16 Verifying : python2-jmespath-0.9.0-3.el7.noarch 6/16 Verifying : python-paramiko-2.1.1-9.el7.noarch 7/16 Verifying : python-babel-0.9.6-8.el7.noarch 8/16 Verifying : ansible-2.4.2.0-2.el7.noarch 9/16 Verifying : python-cffi-1.6.0-5.el7.x86_64 10/16 Verifying : sshpass-1.06-2.el7.x86_64 11/16 Verifying : python-httplib2-0.9.2-1.el7.noarch 12/16 Verifying : python2-pyasn1-0.1.9-7.el7.noarch 13/16 Verifying : python-enum34-1.0.4-1.el7.noarch 14/16 Verifying : python-pycparser-2.14-1.el7.noarch 15/16 Verifying : python2-cryptography-1.7.2-2.el7.x86_64 16/16 Installed: ansible.noarch 0:2.4.2.0-2.el7 Dependency Installed: python-babel.noarch 0:0.9.6-8.el7 python-cffi.x86_64 0:1.6.0-5.el7 python-enum34.noarch 0:1.0.4-1.el7 python-httplib2.noarch 0:0.9.2-1.el7 python-idna.noarch 0:2.4-1.el7 python-jinja2.noarch 0:2.7.2-2.el7 python-markupsafe.x86_64 0:0.11-10.el7 python-paramiko.noarch 0:2.1.1-9.el7 python-passlib.noarch 0:1.6.5-2.el7 python-ply.noarch 0:3.4-11.el7 python-pycparser.noarch 0:2.14-1.el7 python2-cryptography.x86_64 0:1.7.2-2.el7 python2-jmespath.noarch 0:0.9.0-3.el7 python2-pyasn1.noarch 0:0.1.9-7.el7 sshpass.x86_64 0:1.06-2.el7 Complete!安裝Ansible
結果表明，Ansible已經正確安裝。
- 查看Ansible版本號
[root@k3s-vip ~]# ansible --version ansible 2.4.2.0 config file = /etc/ansible/ansible.cfg configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules'] ansible python module location = /usr/lib/python2.7/site-packages/ansible executable location = /usr/bin/ansible python version = 2.7.5 (default, Oct 30 2018, 23:45:53) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)]
Ansible的版本號是2.4.2.0，依賴的Python語言包版本號是2.7.5。
安裝Ansible不是目的，Ansible的強大功能是自動化安裝、部署和運行。下麵以一個小例子來演示Ansible的IT運維能力。
三、建立主機信任關係
Ansible是基於SSH來管理遠程主機的，為了能自動化運行，需要在Ansible管理主機與遠程目標主機之間建立SSH信任關係。
信任關係建立後，Ansible就可以自由訪問目標主機。
- 從Ansible管理主機遠程登錄到目標主機：
以root用戶遠程登錄目標主機，提示時選擇yes，輸入遠程目標主機上的root用戶密碼。因為需要在遠程目標主機上安裝軟體包，使用root用戶是必須的。
[root@k3s-vip ~]# ssh root@k3s-node3 The authenticity of host 'k3s-node3 (192.168.6.193)' can't be established. ECDSA key fingerprint is SHA256:v8yvQmBzZWZrQzhIn4lNMgTsVK7C0lHaEcvdL9cqdno. ECDSA key fingerprint is MD5:a0:aa:14:14:7e:7c:98:67:c1:9a:e4:aa:0d:ce:32:83. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'k3s-node3,192.168.6.193' (ECDSA) to the list of known hosts. root@k3s-node3's password: Last login: Sun Apr 7 11:09:20 2019 from 192.168.6.1
- 在Ansible管理主機生成RSA密鑰對（公鑰/私鑰）
[root@k3s-vip ~]# ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /root/.ssh/id_rsa. Your public key has been saved in /root/.ssh/id_rsa.pub. The key fingerprint is: SHA256:3GNNAxe62c9R505oFL0mkoKYJ53d2XjvP0cIWEsjvX8 root@k3s-vip The key's randomart image is: +---[RSA 2048]----+ | ..o... | | .+= ..| | + + o=B+. +| | + * +.%+* *.| | o S B =oB.o| | . . +o=E| | +o.| | o.| | =| +----[SHA256]-----+
- 複製Ansible管理主機的公鑰到遠程目標主機
[root@k3s-vip ~]# scp -p ~/.ssh/id_rsa.pub root@192.168.6.193:/root/.ssh/authorized_keys root@192.168.6.193's password: 100% 405 605.6KB/s 00:00 id_rsa.pub
- 再次驗證SSH登錄
從Ansible主機SSH登錄到目標主機：
[root@k3s-vip ~]# ssh 192.168.6.193 Last login: Sun Apr 7 12:00:19 2019 from k3s-vip
[root@k3s-node3 ~]#
結果顯示，可以免密碼登錄了。
配置主機信任的過程有點麻煩，但是配置一次就可以永久免密登錄，比起每次登錄輸入密碼還是值得的。
四、配置Ansible環境
新建一個Shell腳本文件show_hosts.sh，功能很簡單，輸出日期時間和/etc/hosts文件的內容到控制台。
編寫遠程安裝的Ansible部署文件，將show_hosts.sh文件安裝到遠程主機的/user/loca/bin目錄下。
在遠程主機運行腳本，然後刪除腳本。
- 新建Shell腳本
[root@k3s-vip ~]# mkdir -p /root/ansible [root@k3s-vip ~]# cd /root/ansible/ [root@k3s-vip ansible]# vi show_hosts.sh [root@k3s-vip ansible]# chmod +x show_hosts.sh [root@k3s-vip ansible]# cat show_hosts.sh #!/usr/bin/bash date cat /etc/hosts
- 在本地測試腳本
[root@k3s-vip ~]# ./show_hosts.sh Sun Apr 7 14:42:22 CST 2019 127.0.0.1 localhost localhost.localdomain 192.168.6.190 k3s-vip 192.168.6.193 k3s-node3
輸出了當前日期時間和/etc/hosts文件的內容。
- 查看Ansible配置目錄
[root@k3s-vip ~]# ls -ln /etc/ansible/ total 24 -rw-r--r-- 1 0 0 19179 Jan 30 2018 ansible.cfg # Ansible配置文件 -rw-r--r-- 1 0 0 1016 Jan 30 2018 hosts # Ansible主機文件 drwxr-xr-x 2 0 0 6 Jan 30 2018 roles # 角色文件
- 修改/etc/ansible/hosts文件
修改hosts文件，在文件最後添加主機組k3s-node以及組內主機IP：
[k3s-node]
192.168.6.193
[root@k3s-vip ~]# cd /etc/ansible/ [root@k3s-vip ansible]# vi hosts [root@k3s-vip ansible]# cat hosts # This is the default ansible 'hosts' file. # ... [k3s-node] 192.168.6.193
- 測試遠程主機的連通性
[root@k3s-vip ansible]# ansible k3s-node -m ping 192.168.6.193 | SUCCESS => { "changed": false, "ping": "pong" }
子命令ping會依次向主機組k3s-node內的各個主機發出報文，驗證網路連通性。
五、編寫playbook劇本文件
playbook是預先編寫的描述性劇本，ansible會逐個執行playbook劇本內的命令。
- 編寫playbook文件
playbook文件是yaml語言格式描述的。show_hosts.yaml劇本分為三個子任務：
複製shell腳本到遠程主機；
在遠程主機執行shell腳本，休眠3秒；
最後刪除腳本。
[root@k3s-vip ansible]# cd /root/ansible/ [root@k3s-vip ansible]# [root@k3s-vip ansible]# cat show_hosts.yaml - name: a sample for show /etc/hosts hosts: k3s-node remote_user: root tasks: - name: copy show_hosts shell file: src: '{{
