用OpenStack Designate构建一个DNS即服务（DNSaaS）

学习如何安装和配置 Designate，这是一个 OpenStack 的多租户 DNS 即服务（DNSaaS）。

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 的当前版本，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;
3. MariaDB [(none)]> GRANT ALL PRIVILEGES ON designate.* TO \
4. 'designate'@'localhost' IDENTIFIED BY 'rhlab123';
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
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
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
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
7. attributes: {}
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
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
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
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
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
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
3. # iptables -I INPUT -p tcp -m multiport --dports 5354 -m comment --comment "Designate mdns incoming" -j ACCEPT
5. # iptables -I INPUT -p tcp -m multiport --dports 53 -m comment --comment "bind incoming" -j ACCEPT
7. # iptables -I INPUT -p udp -m multiport --dports 53 -m comment --comment "bind/powerdns incoming" -j ACCEPT
9. # iptables -I INPUT -p tcp -m multiport --dports 953 -m comment --comment "rndc incoming - bind only" -j ACCEPT
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。