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Linux香港服务器下如何用 OpenStack Designate 实现 DNS 即服务(DNSaaS)

    DNS(Domain Name System)是Internet的重要组成部分,它的核心是为IP地址提供一个更易记住的名字。Internet上的大部分服务都会用到DNS,例如:访问网站,发送邮件,登录软件系统,玩游戏,网络聊天等。浏览器通过域名访问网站的实际过程如下图所示:

DNS从1985年开始被使用。但是为IP地址提供一个更易记住的名字可以追溯到ARPANET(Internet前身)时代。最早的ARPANET网络通过一个hosts.txt文件管理地址和hostname的关系,用户需要DNS服务,就从一个ftp下载host.txt文件到本地。最开始的网络中也就几百台计算机,这种方法没什么问题。但是随着网络的增加,文件存储的方式不能满足规模的要求。为了适应日益增长的网络规模,DNS被提出。

   Designate 是一个多租户的 DNS 即服务,它包括一个用于域名和记录管理的 REST API 和集成了 Neutron 的框架,并支持 Bind9。

DNSaaS 可以提供:

  • 一个管理区域和记录的干净利落的 REST API

  • 自动生成记录(集成 OpenStack)

  • 支持多个授权名字服务器

  • 可以托管多个项目/组织

Designate's architecture

这篇文章解释了如何在 CentOS 和 RHEL 上手动安装和配置 Designate 的最新版本,但是同样的配置也可以用在其它发行版上。

在 OpenStack 上安装 Designate

在我的 GitHub 仓库里,我已经放了 Ansible 的 bind 和 Designate 角色的示范设置。

这个设置假定 bing 服务是安装 OpenStack 控制器节点之外(即使你可以在本地安装 bind)。

1、在 OpenStack 控制节点上安装 Designate 和 bind 软件包:

  1. # yum install openstack-designate-* bind bind-utils -y

2、创建 Designate 数据库和用户:

  1. MariaDB [(none)]> CREATE DATABASE designate CHARACTER SET utf8 COLLATE utf8_general_ci;

  2.      

  3. MariaDB [(none)]> GRANT ALL PRIVILEGES ON designate.* TO \

  4. 'designate'@'localhost' IDENTIFIED BY 'rhlab123';

  5.  

  6. MariaDB [(none)]> GRANT ALL PRIVILEGES ON designate.* TO 'designate'@'%' \

  7. IDENTIFIED BY 'rhlab123';

注意:bind 包必须安装在控制节点之外才能使远程名字服务控制Remote Name Daemon Control(RNDC)功能正常。

配置 bind(DNS 服务器)

1、生成 RNDC 文件:

  1. rndc-confgen -a -k designate -c /etc/rndc.key -r /dev/urandom

  2.  

  3. cat <<EOF> etcrndc.conf

  4. include "/etc/rndc.key";

  5. options {

  6.  default-key "designate";

  7.  default-server {{ DNS_SERVER_IP }};

  8.  default-port 953;

  9. };

  10. EOF

2、将下列配置添加到 named.conf:

  1. include "/etc/rndc.key";

  2. controls {

  3.  inet {{ DNS_SERVER_IP }} allow { localhost;{{ CONTROLLER_SERVER_IP }}; } keys { "designate"; };

  4. };

在 option 节中,添加:

  1. options {

  2.  ...

  3.  allow-new-zones yes;

  4.  request-ixfr no;

  5.  listen-on port 53 { any; };

  6.  recursion no;

  7.  allow-query { 127.0.0.1; {{ CONTROLLER_SERVER_IP }}; };

  8. };

添加正确的权限:

  1. chown named:named /etc/rndc.key

  2. chown named:named /etc/rndc.conf

  3. chmod 600 /etc/rndc.key

  4. chown -v root:named /etc/named.conf

  5. chmod g+w /var/named

  6.  

  7. # systemctl restart named

  8. # setsebool named_write_master_zones 1

3、把 rndc.key 和 rndc.conf 推入 OpenStack 控制节点:

  1. # scp -r /etc/rndc* {{ CONTROLLER_SERVER_IP }}:/etc/

创建 OpenStack Designate 服务和端点

输入:

  1. # openstack user create --domain default --password-prompt designate

  2. # openstack role add --project services --user designate admin

  3. # openstack service create --name designate --description "DNS" dns

  4.  

  5. # openstack endpoint create --region RegionOne dns public http://{{ CONTROLLER_SERVER_IP }}:9001/

  6. # openstack endpoint create --region RegionOne dns internal http://{{ CONTROLLER_SERVER_IP }}:9001/  

  7. # openstack endpoint create --region RegionOne dns admin http://{{ CONTROLLER_SERVER_IP }}:9001/

配置 Designate 服务

1、编辑 /etc/designate/designate.conf:

在 [service:api] 节配置 auth_strategy:

  1. [service:api]

  2. listen = 0.0.0.0:9001

  3. auth_strategy = keystone

  4. api_base_uri = http://{{ CONTROLLER_SERVER_IP }}:9001/

  5. enable_api_v2 = True

  6. enabled_extensions_v2 = quotas, reports

在 [keystone_authtoken] 节配置下列选项:

  1. [keystone_authtoken]

  2. auth_type = password

  3. username = designate

  4. password = rhlab123

  5. project_name = service

  6. project_domain_name = Default

  7. user_domain_name = Default

  8. www_authenticate_uri = http://{{ CONTROLLER_SERVER_IP }}:5000/

  9. auth_url = http://{{ CONTROLLER_SERVER_IP }}:5000/

在 [service:worker] 节,启用 worker 模型:

  1. enabled = True

  2. notify = True

在 [storage:sqlalchemy] 节,配置数据库访问:

  1. [storage:sqlalchemy]

  2. connection = mysql+pymysql://designate:rhlab123@{{ CONTROLLER_SERVER_IP }}/designate

填充 Designate 数据库:

  1. # su -s /bin/sh -c "designate-manage database sync" designate

2、 创建 Designate 的 pools.yaml 文件(包含 target 和 bind 细节):

编辑 /etc/designate/pools.yaml:

  1. - name: default

  2.  # The name is immutable. There will be no option to change the name after

  3.  # creation and the only way will to change it will be to delete it

  4.  # (and all zones associated with it) and recreate it.

  5.  description: Default Pool

  6.  

  7.  attributes: {}

  8.  

  9.  # List out the NS records for zones hosted within this pool

  10.  # This should be a record that is created outside of designate, that

  11.  # points to the public IP of the controller node.

  12.  ns_records:

  13.    - hostname: {{Controller_FQDN}}. # Thisis mDNS

  14.      priority: 1

  15.  

  16.  # List out the nameservers for this pool. These are the actual BIND servers.

  17.  # We use these to verify changes have propagated to all nameservers.

  18.  nameservers:

  19.    - host: {{ DNS_SERVER_IP }}

  20.      port: 53

  21.  

  22.  # List out the targets for this pool. For BIND there will be one

  23.  # entry for each BIND server, as we have to run rndc command on each server

  24.  targets:

  25.    - type: bind9

  26.      description: BIND9 Server 1

  27.  

  28.      # List out the designate-mdns servers from which BIND servers should

  29.      # request zone transfers (AXFRs) from.

  30.      # This should be the IP of the controller node.

  31.      # If you have multiple controllers you can add multiple masters

  32.      # by running designate-mdns on them, and adding them here.

  33.      masters:

  34.        - host: {{ CONTROLLER_SERVER_IP }}

  35.          port: 5354

  36.  

  37.      # BIND Configuration options

  38.      options:

  39.        host: {{ DNS_SERVER_IP }}

  40.        port: 53

  41.        rndc_host: {{ DNS_SERVER_IP }}

  42.        rndc_port: 953

  43.        rndc_key_file: /etc/rndc.key

  44.        rndc_config_file: /etc/rndc.conf

填充 Designate 池:

  1. su -s /bin/sh -c "designate-manage pool update" designate

3、启动 Designate 中心和 API 服务:

  1. systemctl enable --now designate-central designate-api

4、验证 Designate 服务运行:

  1. # openstack dns service list

  2.  

  3. +--------------+--------+-------+--------------+

  4. | service_name | status | stats | capabilities |

  5. +--------------+--------+-------+--------------+

  6. | central      | UP     | -     | -            |

  7. | api          | UP     | -     | -            |

  8. | mdns         | UP     | -     | -            |

  9. | worker       | UP     | -     | -            |

  10. | producer     | UP     | -     | -            |

  11. +--------------+--------+-------+--------------+

用外部 DNS 配置 OpenStack Neutron

1、为 Designate 服务配置 iptables:

  1. # iptables -I INPUT -p tcp -m multiport --dports 9001 -m comment --comment "designate incoming" -j ACCEPT

  2.      

  3. # iptables -I INPUT -p tcp -m multiport --dports 5354 -m comment --comment "Designate mdns incoming" -j ACCEPT

  4.      

  5. # iptables -I INPUT -p tcp -m multiport --dports 53 -m comment --comment "bind incoming" -j ACCEPT

  6.        

  7. # iptables -I INPUT -p udp -m multiport --dports 53 -m comment --comment "bind/powerdns incoming" -j ACCEPT

  8.      

  9. # iptables -I INPUT -p tcp -m multiport --dports 953 -m comment --comment "rndc incoming - bind only" -j ACCEPT

  10.      

  11. # service iptables save; service iptables restart

  12. # setsebool named_write_master_zones 1

2、 编辑 /etc/neutron/neutron.conf 的 [default] 节:

  1. external_dns_driver = designate

3、 在 /etc/neutron/neutron.conf 中添加 [designate] 节:

  1. [designate]

  2. url = http://{{ CONTROLLER_SERVER_IP }}:9001/v2 ## This end point of designate

  3. auth_type = password

  4. auth_url = http://{{ CONTROLLER_SERVER_IP }}:5000

  5. username = designate

  6. password = rhlab123

  7. project_name = services

  8. project_domain_name = Default

  9. user_domain_name = Default

  10. allow_reverse_dns_lookup = True

  11. ipv4_ptr_zone_prefix_size = 24

  12. ipv6_ptr_zone_prefix_size = 116

4、编辑 neutron.conf 的 dns_domain:

  1. dns_domain = rhlab.dev.

重启:

  1. # systemctl restart neutron-*

5、在 /etc/neutron/plugins/ml2/ml2_conf.ini 中的组成层 2(ML2)中添加 dns:

  1. extension_drivers=port_security,qos,dns

6、在 Designate 中添加区域:

  1. # openstack zone create –email=admin@rhlab.dev rhlab.dev.

在 rhlab.dev 区域中添加记录:

  1. # openstack recordset create --record '192.168.1.230' --type A rhlab.dev. Test

Designate 现在就安装和配置好了。