Linux云计算运维架构师（连载）-自动化运维ansible-08

1.1 Ansible模块说明-1

1.1.1 模块综述

Ansible是基于模块进行工作的，用户可以通过命令查看Ansible当前已加载的模块，具体代码如下所示。

[root@ansible ~]# ansible-doc -l

fortios_router_community_list Configure c

azure_rm_devtestlab_info Get Azure D

ecs_taskdefinition register a

avi_alertscriptconfig Module for

tower_receive Receive ass

netapp_e_iscsi_target NetApp E-Se

azure_rm_acs Manage an A

fortios_log_syslogd2_filter Filters for

junos_rpc Runs an arb

na_elementsw_vlan NetApp Elem

pn_ospf CLI command

pn_snmp_vacm CLI command

cp_mgmt_service_sctp Manages ser

onyx_ospf Manage OSPF

icx_command Run arbitra

cs_snapshot_policy Manages vol

nxos_install_os Set boot op

cnos_static_route Manage stat

win_eventlog Manage Wind

vmware_category Manage VMwa

vmware_host_feature_info Gathers inf

avi_cluster Module for

na_ontap_user NetApp ONTA

aci_l3out Manage Laye

memset_server_info Retrieve se

gcp_compute_subnetwork_info Gather info

azure_rm_virtualmachinescalesetextension Manage Azur

fortios_report_dataset Report data

avi_api_session Avi API Mod

avi_networkprofile Module for

avi_backup Module for

aci_interface_policy_cdp Manage CDP

fortios_firewall_vip Configure v

gcp_compute_backend_service Creates a G

iam_policy Manage IAM

fortios_system_fips_cc Configure F

fortios_log_null_device_setting Settings fo

win_inet_proxy Manages pro

fortios_firewall_auth_portal Configure f

:

查看Ansible相关信息之后，终端会进入一个说明界面，按Q键即可退出。Ansible的模块都可以通过命令进行调用，命令格式如下。

ansible [节点] -m [模块] -a [参数]

此处节点可以是某台客户机，也可以是某个主机组，-m用于指定需要调用的模块，-a用于指定参数。除此之外，Ansible还提供了各个模块的具体用法，通过ansible-doc命令即可查看，此处以以shell模块为例进行查看，其结果如下所示。

[root@ansible ~]# ansible-doc shell

> SHELL (/usr/lib/python2.7/site-packages/ansible/modules/commands/she

The `shell' module takes the command name followed by a list

of space-delimited arguments. Either a free form command or

`cmd' parameter is required, see the examples. It is almost

exactly like the [command] module but runs the command through

a shell (`/bin/sh') on the remote node. For Windows targets,

use the [win_shell] module instead.

* This module is maintained by The Ansible Core Team

* note: This module has a corresponding action plugin.

OPTIONS (= is mandatory):

- chdir

Change into this directory before running the command.

[Default: (null)]

type: path

version_added: 0.6

- cmd

The command to run followed by optional arguments.

[Default: (null)]

type: str

- creates

A filename, when it already exists, this step will *not* be

run.

[Default: (null)]

type: path

- executable

Change the shell used to execute the command.

This expects an absolute path to the executable.

[Default: (null)]

type: path

version_added: 0.9

- free_form

:

下面将介绍Ansible常用的七个模块。

1.1.2 shell模块

Ansible的shell模块可以帮助用户在远程主机上执行命令，完成一系列的工作。查看当前Ansible主机清单中的主机内容，代码及结果如下所示。

[root@ansible ~]# cat /etc/ansible/hosts

[apache]

host[1:2]

[nginx]

host3

[webserver:children]

apache

nginx

[webserver:vars]

ansible_ssh_user='root'

ansible_ssh_pass='f'

下面针对该主机清单，使用shell模块来完成一系列的查询或配置操作，示例如下所示。

l 获取主机名

[root@ansible ~]# ansible webserver -m shell -a 'hostname' -o

host2 | CHANGED | rc=0 | (stdout) host2

host3 | CHANGED | rc=0 | (stdout) host3

host1 | CHANGED | rc=0 | (stdout) host1

通过代码的反馈内容可以看到，hosts文件中各客户机的主机名，查询操作完成。

l 指定线程数

[root@ansible ~]# ansible webserver -m shell -a 'hostname' -o -f 2

host2 | CHANGED | rc=0 | (stdout) host2

host1 | CHANGED | rc=0 | (stdout) host1

host3 | CHANGED | rc=0 | (stdout) host3

使用“-f”可以指定Ansible一次命令执行并发的线程数，这里指定werserver组中所有主机的线程数为2。

l 部署Apache

[root@ansible ~]# ansible host2 -m shell -a 'yum -y install httpd' -o

host2 | CHANGED | rc=0 | (stdout) 已加载插件：

.............

已安装:

httpd.x86_64 0:2.4.6-97.el7.centos

作为依赖被安装:

apr.x86_64 0:1.4.8-7.el7

apr-util.x86_64 0:1.5.2-6.el7

httpd-tools.x86_64 0:2.4.6-97.el7.centos

mailcap.noarch 0:2.1.41-2.el7

完毕！

通过代码的反馈结果可以看到，host2主机已成功安装Apache。在host2中查看其版本号，结果如下所示。

[root@host2 ~]# httpd -v

Server version: Apache/2.4.6 (CentOS)

Server built: Nov 16 2020 16:18:20

l 查询系统负载

#查询host3的系统负载

[root@ansible ~]# ansible host3 -m shell -a 'uptime' -o

host3 | CHANGED | rc=0 | (stdout) 22:43:00 up 3:26, 3 users, load average: 0.00, 0.01, 0.05

通过代码的反馈结果可以看到host3客户机的系统负载信息。除了上面这些之外，Ansible可用的命令及参数还有很多，一些常用的参数如表1.3所示。

表1.1 shell模块常用参数