openstack运维实战系列之neutron替换instance的IP

Posted 2020-06-08

1. 背景说明

  生产环境下openstack使用了vlan的的网络模式，针对业务需求不同，设置不同的网段，分别放置在不通的vlan中，通过vlan的方式，实现网络的隔离，网络相关的策略，可以通过现有的交换机,防火墙来设置。有时候，业务申请的虚拟机使用一段时间之后，需要将网络A切换至另外一个网络B，并且需要保留原有的虚拟机和数据，对于这种场景，就可以通过neutron端口替换的方式实现。

  neutron在openstack中负责虚拟机网络相关的服务，作为一种插件式的服务，neutron能够支持各种插件，包括OpenVswitch,Cisco插件，Boacade等网络厂商的插件，同时为了网络的可扩展性和tenant之间的流量隔离，neutron能够支持多种网络隔离技术，常见的隔离技术包括:vlan,gre,vxlan,gre,linux bridge等。根据使用场景的不同，可以选择不同的网络模式，我所在的工作环境中，使用的网络模式为vlan。关于网络的说明，请继续关注我的博客，此处不再赘述。

2. 实现过程

1. 查看需要替换地址的instance

[[email protected] ~]# nova list |grep 192.168.100.200
| 3f694eaf-aa87-456a-99ce-90dd9f4e45ee | happyblog_blog_51cto_com | ACTIVE | -          | Running     | vmTest=192.168.100.200   | ChuangYiYuan_10_16_2_11 |

#需要将192.168.100.200这台机器的ip，替换成10.16.4.x网段的ip地址

2. 将instance的port卸载

#将port从instance中detach 
[[email protected] ~]# nova interface-detach 3f694eaf-aa87-456a-99ce-90dd9f4e45ee  4c158efa-6cba-4d62-99d7-590877586c09    

[[email protected] ~]# nova list |grep 3f694eaf-aa87-456a-99ce-90dd9f4e45ee
| 3f694eaf-aa87-456a-99ce-90dd9f4e45ee | happyblog_blog_51cto_com | ACTIVE | -          | Running     |                         | ChuangYiYuan_10_16_2_11|

#发现instance 3f694eaf-aa87-456a-99ce-90dd9f4e45ee此时没有IP地址了！！

3. 基于指定的sunbet创建一个端口

[[email protected] ~]# neutron subnet-list
+--------------------------------------+----------------+------------------+------------------------------------------------------+
| id                                   | name           | cidr             | allocation_pools                                     |
+--------------------------------------+----------------+------------------+------------------------------------------------------+
| 79cb82a1-eac1-4311-8e6d-badcabd22e44 | ForTest        | 192.168.100.0/24 | {"start": "192.168.100.2", "end": "192.168.100.254"} |
| 9654a807-d4fa-49f1-abb6-2e45d776c69f | Subnet_INSIDE  | 10.16.4.0/23     | {"start": "10.16.4.10", "end": "10.16.5.254"}        |#基于该subnet创建port

查看network情况
[[email protected] ~]# neutron net-list
+--------------------------------------+---------------+-------------------------------------------------------+
| id                                   | name          | subnets                                               |
+--------------------------------------+---------------+-------------------------------------------------------+
| 43b5c341-c22d-445a-94d1-e2c84722ad4e | vmProdution   | 9654a807-d4fa-49f1-abb6-2e45d776c69f 10.16.4.0/23     |   #网络ID好，后续使用
| 99c68a93-336a-4605-aa78-343d41ca1206 | vmTest        | 79cb82a1-eac1-4311-8e6d-badcabd22e44 192.168.100.0/24 |
+--------------------------------------+---------------+-------------------------------------------------------+

#基于指定的subnet，创建一个端口port
[[email protected] ~]# neutron port-create --name port-1  --fixed-ip subnet_id=9654a807-d4fa-49f1-abb6-2e45d776c69f,ip_address=10.16.4.58  --security-group 663468d9-73b1-4b04-8d4c-dac1bf21a94d  43b5c341-c22d-445a-94d1-e2c84722ad4e        
Created a new port:
+-----------------------+-----------------------------------------------------------------------------------+
| Field                 | Value                                                                             |
+-----------------------+-----------------------------------------------------------------------------------+
| admin_state_up        | True                                                                              |
| allowed_address_pairs |                                                                                   |
| binding:host_id       |                                                                                   |
| binding:profile       | {}                                                                                |
| binding:vif_details   | {}                                                                                |
| binding:vif_type      | unbound                                                                           |
| binding:vnic_type     | normal                                                                            |
| device_id             |                                                                                   |
| device_owner          |                                                                                   |
| fixed_ips             | {"subnet_id": "9654a807-d4fa-49f1-abb6-2e45d776c69f", "ip_address": "10.16.4.58"} |   #指定的ip地址了
| id                    | ae64c08e-ac2e-4a28-ae89-0d4d2fb67981                                              |   #ID号码，记住
| mac_address           | fa:16:3e:1d:c0:9a                                                                 |
| name                  | port-1                                                                            |
| network_id            | 43b5c341-c22d-445a-94d1-e2c84722ad4e                                              |
| security_groups       | 663468d9-73b1-4b04-8d4c-dac1bf21a94d                                              |
| status                | DOWN                                                                              |
| tenant_id             | 842ab3268a2c47e6a4b0d8774de805ae                                                  |
+-----------------------+-----------------------------------------------------------------------------------+

#查看端口的信息
[[email protected] ~]# neutron port-list |grep  ae64c08e-ac2e-4a28-ae89-0d4d2fb67981 
| ae64c08e-ac2e-4a28-ae89-0d4d2fb67981 | port-1 | fa:16:3e:1d:c0:9a | {"subnet_id": "9654a807-d4fa-49f1-abb6-2e45d776c69f", "ip_address": "10.16.4.58"}  |
[[email protected] ~]# 
[[email protected] ~]# neutron port-show  ae64c08e-ac2e-4a28-ae89-0d4d2fb67981 
+-----------------------+-----------------------------------------------------------------------------------+
| Field                 | Value                                                                             |
+-----------------------+-----------------------------------------------------------------------------------+
| admin_state_up        | True                                                                              |
| allowed_address_pairs |                                                                                   |
| binding:host_id       |                                                                                   |
| binding:profile       | {}                                                                                |
| binding:vif_details   | {}                                                                                |
| binding:vif_type      | unbound                                                                           |
| binding:vnic_type     | normal                                                                            |
| device_id             |                                                                                   |
| device_owner          |                                                                                   |
| extra_dhcp_opts       |                                                                                   |
| fixed_ips             | {"subnet_id": "9654a807-d4fa-49f1-abb6-2e45d776c69f", "ip_address": "10.16.4.58"} |
| id                    | ae64c08e-ac2e-4a28-ae89-0d4d2fb67981                                              |
| mac_address           | fa:16:3e:1d:c0:9a                                                                 |
| name                  | port-1                                                                            |
| network_id            | 43b5c341-c22d-445a-94d1-e2c84722ad4e                                              |
| security_groups       | 663468d9-73b1-4b04-8d4c-dac1bf21a94d                                              |
| status                | DOWN                                                                              |
| tenant_id             | 842ab3268a2c47e6a4b0d8774de805ae                                                  |
+-----------------------+-----------------------------------------------------------------------------------+

4. 将所创建的port和instance关联

[[email protected] ~]# nova list |grep happy
| 3f694eaf-aa87-456a-99ce-90dd9f4e45ee | happyblog_blog_51cto_com | ACTIVE | -          | Running     |                         | ChuangYiYuan_10_16_2_11 |
#执行关联操作，用法参考nova help interface-attach
[[email protected] ~]# nova interface-attach --port-id ae64c08e-ac2e-4a28-ae89-0d4d2fb67981 3f694eaf-aa87-456a-99ce-90dd9f4e45ee
[[email protected] ~]# nova list |grep 3f694eaf-aa87-456a-99ce-90dd9f4e45ee
| 3f694eaf-aa87-456a-99ce-90dd9f4e45ee | happyblog_blog_51cto_com | ACTIVE | -          | Running     | vmProdution=10.16.4.58   | ChuangYiYuan_10_16_2_11 |
#关联完毕!!!

3. 小结

   关于端口的替换，可以参考上面的例子，neutron作为可插拔式的服务，其port可以随便切换，这也是neutron的强大之处。

本文出自 “Happy实验室” 博客，转载请与作者联系！