Chef - 使用 dnmsasq 防止多个服务重新启动或重新加载？

Question

如何在一次主厨运行中实现一次重启/重新加载并符合主厨最佳实践？

使用状态文件是一种好习惯还是重写服务 dnsmasq 信息？

这个问题是 7 年前提出的，有人找到更好的方法吗？ 此处记录的重写服务 --
Minimize service restarts from chef notifications?

问题：

当前代码已导致 1 次重新启动和 1 次重新加载。这导致了问题。

dnsmasq 有 3 个配置文件，需要使用不同的启动/重启/重新加载方法进行管理。 dnsmasq 在设计上将 no-poll 作为参数，以防止它在每次更改时重新加载 /etc/resolv.conf。我想在这里控制重载。

package "install dnsmasq" do
  name 'dnsmasq'
  action :install
  notifies :create, 'cookbook_file[/etc/dnsmasq.conf]', :delayed
  notifies :create, 'template[/etc/resolv.dnsmasq]', :delayed
  notifies :create, 'template[/etc/resolv.conf]', :delayed
  notifies :restart, 'service[dnsmasq]', :delayed
end

template '/etc/resolv.dnsmasq' do
  ...
  notifies :reload, 'service[dnsmasq]', :delayed
end

file '/etc/dnsmasq.conf' do
  ...
  notifies :restart, 'service[dnsmasq]', :delayed
end

template '/etc/resolv.conf' do
  ...
  notifies :reload, 'service[dnsmasq]', :delayed
end

service 'dnsmasq' do
  supports [:restart, :status, :start, :reload]
  action [ :enable, :start ]
  reload_command "/usr/bin/killall -s SIGHUP dnsmasq"
end

Answer 1

如果你做的不止这些：

package "install dnsmasq" do
  name 'dnsmasq'
  action :install
end

file '/etc/dnsmasq.conf' do
  ...
  notifies :restart, 'service[dnsmasq]', :delayed
end

template '/etc/resolv.dnsmasq' do
  ...
  notifies :reload, 'service[dnsmasq]', :delayed
end

template '/etc/resolv.conf' do
  ...
  notifies :reload, 'service[dnsmasq]', :delayed
end

service 'dnsmasq' do
  supports [:restart, :status, :start, :reload]
  action [ :enable, :start ]
  reload_command "/usr/bin/killall -s SIGHUP dnsmasq"
end

那么您的代码中可能存在逻辑问题，因为您在这些文件中放置了什么，这些资源是幂等的，从包安装通知模板和文件然后通知服务重启在声明性模型上是无稽之谈。

这里不需要使用通知， :delayed 也不是必需的，因为它是默认值，但它在阅读时会很明显。

首先放置 /etc/dnsmasq.conf 文件以确保在需要时在任何重新加载之前首先触发重新启动通知，以避免重新加载需要重新启动的配置更改。重启后重新加载完全没有问题。

Answer 2

这种“累加器”解决方案会导致一次启动、重新启动或重新加载，具体取决于传递的内容。该过程以前被称为倒带。这可能不是非常有效的编码或在 Chef 中执行此类活动的正确方法，但该解决方案目前对我有用。

配方：dnsmasq.rb

dnsmasq_service 'dnsmasq' do
  action :nothing
end

package 'dnsmasq' do
  action :install
end

# This has to come first, as it requires a restart
cookbook_file '/etc/dnsmasq.conf' do
  delayed_action :create
  notifies :restart, 'dnsmasq_service[dnsmasq]'
end

# This comes second
template '/etc/resolv.dnsmasq' do
  delayed_action :create
  notifies :reload, 'dnsmasq_service[dnsmasq]'
end

# This comes third.  Do not create until the other configs are down.
template '/etc/resolv.conf' do
  delayed_action :create
  notifies :reload, 'dnsmasq_service[dnsmasq]'
end

# This comes fourth
# Make sure the service is always started and enabled.
service 'dnsmasq' do
  action [ :enable, :start ]
  delayed_action :start
end

资源：dnsmasq_service.rb

#https://github.com/chef/chef/issues/5454
# Be aware of the cookbook name being lost
#https://github.com/chef/chef/issues/5438
# Could not get this to work without the log notifications.

#https://coderanger.net/rewind/
#https://docs.chef.io/infra_language/

provides :dnsmasq_service
resource_name :dnsmasq_service

default_action :start

action :start do
  # Find resource, if it does not exist create with this action
  with_run_context :root do
    find_resource(:service, 'dnsmasq') do
      action [ :enable, :start ]
    end
  end
  log "force :start dnsmasq notification" do
    notifies :start, 'service[dnsmasq]', :delayed
  end
end

action :reload do
  r = with_run_context :root do
    find_resource(:service, 'dnsmasq') do
      action [ :enable, :reload ]
      reload_command "/usr/bin/killall -s SIGHUP dnsmasq"
    end
  end

  a = Array.new(r.action)
  f_act = :reload
  if a.include?(:restart)
    f_act = :restart
    with_run_context :root do
      edit_resource!(:service, 'dnsmasq') do
        action [ :enable, :restart ]
      end
    end
  else
    with_run_context :root do
      edit_resource!(:service, 'dnsmasq') do
        action [ :enable, :reload ]
        reload_command "/usr/bin/killall -s SIGHUP dnsmasq"
      end
    end
  end
  log "force #{f_act} dnsmasq notification" do
    notifies f_act, 'service[dnsmasq]', :delayed
  end
end

action :restart do
  r = with_run_context :root do
    find_resource(:service, 'dnsmasq') do
      action [ :enable, :reload ]
    end
  end

  with_run_context :root do
    edit_resource!(:service, 'dnsmasq') do
      action [ :enable, :restart ]
    end
  end
  log "force :restart dnsmasq notification" do
    notifies :restart, 'service[dnsmasq]', :delayed
  end
end