nova-docker现状
nova-docker插件h版出现，但是在i版本从nova中移出，作为孵化项目培养。
当时给出的解释是，希望能更快的进行迭代开发，支持cinder和neutron。并计划在K版本release时重新进入。
nova-docker的架构
目前的架构如下（其中docker registry已经不需要了）。
从图中可以看出，这种使用方法，docker相当于一种新的hypervisor。
把容器当做虚拟机来使用。
其中容器镜像通过docker save保存成tar包，放置在glance上管理。
创建容器时，从glance上下载容器镜像，利用（docker load）加载并启动容器镜像。
支持功能
- 支持容器创建/删除/软删除/重启/暂停/解除暂定/停止/开始。
- 支持对容器创建快照，支持基于快照恢复容器。
- 支持对容器设置插拔网卡。
- 查询docker节点上CPU/内存使用情况/查询可用节点。
- 查询docker容器。
- 查询容器console输出。
- 支持neutron网络/nova-network网络。
- 支持绑定浮动IP。
- 不支持共享存储。
- 不支持挂卷/卸卷操作。
- 不支持迁移，rescue等操作。
- 不支持设置安全组规则。（从代码上看，留的有框架，但是目前并不支持。使用的NoopFirewallDriver。)
- 容器使用的是本地存储，不能使用cinder共享存储。
#p#
网络实现
查看容器的namespace:
- [root@localhost ~]# docker ps --no-trunc
- CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
- 54ba6c67de05b8c5ddb824497eae0071f902dcdea05ce93109d9791453dfeb17 tutum/wordpress:latest "/run.sh" 15 hours ago Up 15 hours nova-ee2edd99-a64c-4701-84ad-faccd3b1a246
- [root@localhost ~]# ip netns list
- 54ba6c67de05b8c5ddb824497eae0071f902dcdea05ce93109d9791453dfeb17
- qdhcp-78277811-dc20-47c0-8319-58894843e3d4
- 3ce4e73bcfeb64b994a5bf87c7f49553ca3583308b93878a07679a742661b0a4
- qdhcp-bc557a68-425e-4f24-bb6c-627500647856
- ee3b2cc56a0ccae387371cf8eb6ad7f43712cf1cbdc66bf46af77f3c929be34a
- qrouter-818c4149-355d-4409-8dda-f412da898ff0
查看namespace中网络：
- [root@localhost ~]# ip netns exec 54ba6c67de05b8c5ddb824497eae0071f902dcdea05ce93109d9791453dfeb17 ip addr
- 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
- link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
- inet 127.0.0.1/8 scope host lo
- valid_lft forever preferred_lft forever
- inet6 ::1/128 scope host
- valid_lft forever preferred_lft forever
- 28: nse54c9783-26: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
- link/ether fa:16:3e:d8:9b:e8 brd ff:ff:ff:ff:ff:ff
- inet 10.0.0.2/24 brd 10.0.0.255 scope global nse54c9783-26
- valid_lft forever preferred_lft forever
- inet6 fe80::f816:3eff:fed8:9be8/64 scope link
- valid_lft forever preferred_lft forever
查看设备28的关联veth pair：
- [root@localhost ~]# ip netns exec 54ba6c67de05b8c5ddb824497eae0071f902dcdea05ce93109d9791453dfeb17 ethtool -S nse54c9783-26
- NIC statistics:
- peer_ifindex: 29
- [root@localhost ~]# ip addr
- ...
- 29: tape54c9783-26: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master ovs-system state UP qlen 1000
- link/ether 82:31:7f:dc:e3:8f brd ff:ff:ff:ff:ff:ff
- inet6 fe80::8031:7fff:fedc:e38f/64 scope link
- valid_lft forever preferred_lft forever
- ...
查看设备29关联设备：(设备挂在OVS网桥的br-int上）
- [root@localhost ~]# ovs-vsctl show
- 2368aead-599b-4cd8-b2a1-dd01041e5635
- Bridge br-ex
- Port br-ex
- Interface br-ex
- type: internal
- Port "qg-83cd012e-53"
- Interface "qg-83cd012e-53"
- type: internal
- Bridge br-int
- fail_mode: secure
- Port "tapbf138559-94"
- tag: 3
- Interface "tapbf138559-94"
- Port "tape54c9783-26"
- tag: 1
- Interface "tape54c9783-26"
- Port "tap7687fcec-f0"
- tag: 2
- Interface "tap7687fcec-f0"
- Port br-int
- Interface br-int
- type: internal
- Port "qr-9712c2ca-1f"
- tag: 1
- Interface "qr-9712c2ca-1f"
- type: internal
- Port patch-tun
- Interface patch-tun
- type: patch
- options: {peer=patch-int}
- Port "tap5f8409aa-f9"
- tag: 3
- Interface "tap5f8409aa-f9"
- type: internal
- Port "tapeb9206a8-85"
- tag: 1
- Interface "tapeb9206a8-85"
- type: internal
- Bridge br-tun
- Port patch-int
- Interface patch-int
- type: patch
- options: {peer=patch-tun}
- Port br-tun
- Interface br-tun
- type: internal
- ovs_version: "2.0.0"
备注：因为是个单机环境，没有给br-int配置具体的物理网卡。
容器DHCP服务与绑定Floating IP:
- //10.0.0.0/24网段的DHCP服务
- [root@localhost ~]# ip netns exec qdhcp-78277811-dc20-47c0-8319-58894843e3d4 ip addr
- 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
- link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
- inet 127.0.0.1/8 scope host lo
- valid_lft forever preferred_lft forever
- inet6 ::1/128 scope host
- valid_lft forever preferred_lft forever
- 27: tapeb9206a8-85: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
- link/ether fa:16:3e:6e:1b:13 brd ff:ff:ff:ff:ff:ff
- inet 10.0.0.3/24 brd 10.0.0.255 scope global tapeb9206a8-85
- valid_lft forever preferred_lft forever
- inet6 fe80::f816:3eff:fe6e:1b13/64 scope link
- valid_lft forever preferred_lft forever
- //可以看出通过router将内部10.0.0.0/24的网络与外部172.24.4.0/24的两个IP打通
- [root@localhost ~]# ip netns exec qrouter-818c4149-355d-4409-8dda-f412da898ff0 ip addr
- 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
- link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
- inet 127.0.0.1/8 scope host lo
- valid_lft forever preferred_lft forever
- inet6 ::1/128 scope host
- valid_lft forever preferred_lft forever
- 19: qr-9712c2ca-1f: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
- link/ether fa:16:3e:50:18:19 brd ff:ff:ff:ff:ff:ff
- inet 10.0.0.1/24 brd 10.0.0.255 scope global qr-9712c2ca-1f
- valid_lft forever preferred_lft forever
- inet6 fe80::f816:3eff:fe50:1819/64 scope link
- valid_lft forever preferred_lft forever
- 20: qg-83cd012e-53: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
- link/ether fa:16:3e:0d:4e:c2 brd ff:ff:ff:ff:ff:ff
- inet 172.24.4.2/24 brd 172.24.4.255 scope global qg-83cd012e-53
- valid_lft forever preferred_lft forever
- inet 172.24.4.6/32 brd 172.24.4.6 scope global qg-83cd012e-53
- valid_lft forever preferred_lft forever
- inet6 fe80::f816:3eff:fe0d:4ec2/64 scope link
- valid_lft forever preferred_lft forever
- //IP绑定的NAT规则
- [root@localhost ~]# ip netns exec qrouter-818c4149-355d-4409-8dda-f412da898ff0 iptables-save
- -A neutron-l3-agent-PREROUTING -d 172.24.4.6/32 -j DNAT --to-destination 10.0.0.2
- -A neutron-l3-agent-float-snat -s 10.0.0.2/32 -j SNAT --to-source 172.24.4.6
参考：
1. http://www.opencontrail.org/openstack-docker-opencontrail/
2. http://technodrone.blogspot.com/2014/10/nova-docker-on-juno.html
本文出自：http://blog.csdn.net/halcyonbaby/article/details/41855917
