0.理解Aodh
Aodh是Openstack告警项目，最初在Havana版本中作为Ceilometer项目的一个组件(ceilometer-alarm)出现在Ceilometer项目中，在Liberty版本中演变成了独立项目Aodh，用户可以为独立事件或者样本设置阈值和告警机制。
Aodh服务由以下组件组成：
1.先睹为快
不想看下面大段的代码解析，已经跃跃欲试了？
OK，我们开始吧！
打开虚拟机终端并输入以下命令：
$ puppet apply examples/aodh.pp
等待命令执行完成，Puppet完成了对Aodh服务的安装。
注：部署Aodh服务，依赖于Keystone服务。
2.核心代码讲解
class aodh
class aodh完成了以下三项任务:
其中rabbit和AMQP相关的选项管理均是通过oslo::messaging::rabbit和oslo::messaging::amqp来管理，关于puppet-oslo模块，将会在下一个章节详细介绍。
oslo::messaging::rabbit { 'aodh_config':
rabbit_userid => $rabbit_userid,
rabbit_password => $rabbit_password,
rabbit_virtual_host => $rabbit_virtual_host,
rabbit_host => $rabbit_host,
rabbit_port => $rabbit_port,
rabbit_hosts => $rabbit_hosts,
rabbit_ha_queues => $rabbit_ha_queues,
heartbeat_timeout_threshold => $rabbit_heartbeat_timeout_threshold,
heartbeat_rate => $rabbit_heartbeat_rate,
rabbit_use_ssl => $rabbit_use_ssl,
kombu_reconnect_delay => $kombu_reconnect_delay,
kombu_ssl_version => $kombu_ssl_version,
kombu_ssl_keyfile => $kombu_ssl_keyfile,
kombu_ssl_certfile => $kombu_ssl_certfile,
kombu_ssl_ca_certs => $kombu_ssl_ca_certs,
kombu_compression => $kombu_compression,
amqp_durable_queues => $amqp_durable_queues,
}
在package资源中，有一个元属性tag:
package { 'aodh':
ensure => $package_ensure_real,
name => $::aodh::params::common_package_name,
tag => ['openstack', 'aodh-package'],
}
tag顾名思义就是标签，资源、类和定义都可以对其标记，一个资源可以有任意数量的标记。有多种标记资源的方式，以上代码是使用了元参数tag，对aodh package资源 添加了2个tag：'openstack','aodh-package'。这些tag会在aodh::deps中使用，用于收集标记为aodh-package的package资源:
anchor { 'aodh::install::begin': }
-> Package<| tag == 'aodh-package'|>
~> anchor { 'aodh::install::end': }
class aodh::api
api的主要是提供数据的接口，为告警数据的提供存储和访问。在class aodh::api中先是定义了以下几个依赖关系：
if $auth_strategy == 'keystone' {
include ::aodh::keystone::authtoken
}
Aodh_config<||> ~> Service[$service_name]
Class['aodh::policy'] ~> Service[$service_name]
Package['aodh-api'] -> Service[$service_name]
Package['aodh-api'] -> Service['aodh-api']
Package['aodh-api'] -> Class['aodh::policy']
package { 'aodh-api':
ensure => $package_ensure,
name => $::aodh::params::api_package_name,
tag => ['openstack', 'aodh-package'],
}
代码中两种符号'->'和'~>'，这两者都是描述资源间的依赖，前面已经介绍过。同时在模块中都同样使用keystone作为认证。API类中其余代码则是对参数进行配置，略过。
class aodh::evaluator
if $manage_service {
if $enabled {
$service_ensure = 'running'
} else {
$service_ensure = 'stopped'
}
}
Package['aodh'] -> Service['aodh-evaluator']
service { 'aodh-evaluator':
ensure => $service_ensure,
name => $::aodh::params::evaluator_service_name,
enable => $enabled,
hasstatus => true,
hasrestart => true,
tag => ['aodh-service','aodh-db-sync-service']
}
)
aodh-evaluator 服务的部署和 aodh-api 类似，配置一些基础配置和 oslo 相关配置，就可以启动服务了。
class aodh::notifier
Package['aodh'] -> Service['aodh-notifier']
service { 'aodh-notifier':
ensure => $service_ensure,
name => $::aodh::params::notifier_service_name,
enable => $enabled,
hasstatus => true,
hasrestart => true,
tag => 'aodh-service',
}
}
class aodh::listener
Package['aodh'] -> Service['aodh-listener']
service { 'aodh-listener':
ensure => $service_ensure,
name => $::aodh::params::listener_service_name,
enable => $enabled,
hasstatus => true,
hasrestart => true,
tag => 'aodh-service',
}
}
小结
从上述的代码中，咱们可清晰看到aodh的安装、数据库创建与同步、认证、api、evaluator、notifier、listener服务的配置、启动、管理。源于aodh手动部署文档。
动手练习
