當搭建完openstack之後，在建立instance之前，第一件事情就是建立network，一個經典的流程如下：

TENANT_NAME="openstack"
TENANT_NETWORK_NAME="openstack-net"
TENANT_SUBNET_NAME="${TENANT_NETWORK_NAME}-subnet"
TENANT_ROUTER_NAME="openstack-router"
FIXED_RANGE="NEUTRON_FIXED_RANGE"
NETWORK_GATEWAY="NEUTRON_NETWORK_GATEWAY"

PUBLIC_GATEWAY="NEUTRON_PUBLIC_GATEWAY"
PUBLIC_RANGE="NEUTRON_PUBLIC_RANGE"
PUBLIC_START="NEUTRON_PUBLIC_START"
PUBLIC_END="NEUTRON_PUBLIC_END"

(1) 建立private network和subnet

TENANT_ID=$(keystone tenant-list | grep " $TENANT_NAME " | awk '{print $2}')

TENANT_NET_ID=$(neutron net-create --tenant_id $TENANT_ID $TENANT_NETWORK_NAME --provider:network_type gre --provider:segmentation_id 1 | grep " id " | awk '{print $4}')

TENANT_SUBNET_ID=$(neutron subnet-create --tenant_id $TENANT_ID --ip_version 4 --name $TENANT_SUBNET_NAME $TENANT_NET_ID $FIXED_RANGE --gateway $NETWORK_GATEWAY --dns_nameservers list=true 8.8.8.8 | grep " id " | awk '{print $4}')

當僅有private network的時候，會對這個private network建立一個DHCP Server

所以DHCP Agent會執行下面的命令：

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip -o link show tap452bdfab-31

這個命令試圖從dhcp的namespace裡面查詢dhcp的網路卡，但是很可惜找不到，返回error

Cannot open network namespace "qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0": No such file or directory

於是試圖建立dhcp server的網路卡，這個網路卡會attach到br-int上，所以先檢視br-int

ip -o link show br-int

如果br-int沒有問題，於是建立dhcp server的網路卡，並且attach到br-int上

ovs-vsctl -- --if-exists del-port tap452bdfab-31 -- add-port br-int tap452bdfab-31 -- set Interface tap452bdfab-31 type=internal -- set Interface tap452bdfab-31 external-ids:iface-id=452bdfab-3152-44d0-bd9c-40c94a6f8640 -- set Interface tap452bdfab-31 external-ids:iface-status=active -- set Interface tap452bdfab-31 external-ids:attached-mac=fa:16:3e:d7:08:67

為網路卡設定mac

ip link set tap452bdfab-31 address fa:16:3e:d7:08:67

檢視當前存在的namespace

ip -o netns list

返回

qrouter-26a45e0e-a58a-443b-a972-d62c0c5a1323

qdhcp-760d2c5e-4938-49b0-bffe-c77c5b141d18

發現沒有這個dhcp所對應的namespace，需要建立一個

ip netns add qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0

將io網路卡設定為up

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip link set lo up

將新建的dhcp server的網路卡放在這個namespace裡面

ip link set tap452bdfab-31 netns qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0

將DHCP server的網路卡設定為up

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip link set tap452bdfab-31 up

檢視這個網路卡的ip地址

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip addr show tap452bdfab-31 permanent scope global

為這個網路卡配置ip地址

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip -4 addr add 192.168.10.3/24 brd 192.168.10.255 scope global dev tap452bdfab-31

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip -4 addr add 169.254.169.254/16 brd 169.254.255.255 scope global dev tap452bdfab-31

第一個地址是dhcp server的地址，第二個地址是metadata server的地址

檢視路由表

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip route list dev tap452bdfab-31

169.254.0.0/16  proto kernel  scope link  src 169.254.169.254

192.168.10.0/24  proto kernel  scope link  src 192.168.10.3

新增路由表

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip route replace default via 192.168.10.1 dev tap452bdfab-31

檢視網路卡的配置

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip addr show tap452bdfab-31

232: tap452bdfab-31: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default

link/ether fa:16:3e:d7:08:67 brd ff:ff:ff:ff:ff:ff

inet 192.168.10.3/24 brd 192.168.10.255 scope global tap452bdfab-31

valid_lft forever preferred_lft forever

inet 169.254.169.254/16 brd 169.254.255.255 scope global tap452bdfab-31

valid_lft forever preferred_lft forever

inet6 fe80::f816:3eff:fed7:867/64 scope link tentative

valid_lft forever preferred_lft forever

啟動dhcp server

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 env NEUTRON_NETWORK_ID=66b9930b-2871-414c-8c6f-991a6a8cffe0 dnsmasq --no-hosts --no-resolv --strict-order --bind-interfaces --interface=tap452bdfab-31 --except-interface=lo --pid-file=/var/lib/neutron/dhcp/66b9930b-2871-414c-8c6f-991a6a8cffe0/pid --dhcp-hostsfile=/var/lib/neutron/dhcp/66b9930b-2871-414c-8c6f-991a6a8cffe0/host --addn-hosts=/var/lib/neutron/dhcp/66b9930b-2871-414c-8c6f-991a6a8cffe0/addn_hosts --dhcp-optsfile=/var/lib/neutron/dhcp/66b9930b-2871-414c-8c6f-991a6a8cffe0/opts --leasefile-ro --dhcp-range=set:tag0,192.168.10.0,static,86400s --dhcp-lease-max=256 --conf-file= --domain=openstacklocal

啟動metadata proxy

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 neutron-ns-metadata-proxy --pid_file=/var/lib/neutron/external/pids/66b9930b-2871-414c-8c6f-991a6a8cffe0.pid --metadata_proxy_socket=/var/lib/neutron/metadata_proxy --network_id=66b9930b-2871-414c-8c6f-991a6a8cffe0 --state_path=/var/lib/neutron --metadata_port=80 --debug --verbose --log-file=neutron-ns-metadata-proxy-66b9930b-2871-414c-8c6f-991a6a8cffe0.log --log-dir=/var/log/neutron

最後檢視一下網路卡配置

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip addr show tap452bdfab-31

kill -HUP 17666

這個PID是什麼呢？

# ps aux | grep 17666
nobody   17666  0.0  0.0  28204  1112 ?        S    Jul14   0:00 dnsmasq --no-hosts --no-resolv --strict-order --bind-interfaces --interface=tap452bdfab-31 --except-interface=lo --pid-file=/var/lib/neutron/dhcp/66b9930b-2871-414c-8c6f-991a6a8cffe0/pid --dhcp-hostsfile=/var/lib/neutron/dhcp/66b9930b-2871-414c-8c6f-991a6a8cffe0/host --addn-hosts=/var/lib/neutron/dhcp/66b9930b-2871-414c-8c6f-991a6a8cffe0/addn_hosts --dhcp-optsfile=/var/lib/neutron/dhcp/66b9930b-2871-414c-8c6f-991a6a8cffe0/opts --leasefile-ro --dhcp-range=set:tag0,192.168.10.0,static,86400s --dhcp-lease-max=256 --conf-file= --domain=openstacklocal

原來是我們的dhcp server

這個命令的作用是：如果想要更改配置而不需停止並重新啟動服務，請使用該命令。在對配置檔案作必要的更改後，發出該命令以動態更新服務配置。

最後檢視一下路由配置

ip netns exec qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0 ip route list dev tap452bdfab-31

(2) 建立一個router，並且和private network相連

ROUTER_ID=$(neutron router-create --tenant_id $TENANT_ID $TENANT_ROUTER_NAME | grep " id " | awk '{print $4}')

neutron router-interface-add $ROUTER_ID $TENANT_SUBNET_ID

檢視br-ex

ip -o link show br-ex

59: br-ex: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default

link/ether a0:48:1c:ab:df:b5 brd ff:ff:ff:ff:ff:ff

檢視所有的namespace

ip -o netns list

qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0

qrouter-26a45e0e-a58a-443b-a972-d62c0c5a1323

qdhcp-760d2c5e-4938-49b0-bffe-c77c5b141d18

發現沒有這個router的namespace，建立一個

ip netns add qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82

將io網路卡設為up

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip link set lo up

這是一個router，所以enable ip forward

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 sysctl -w net.ipv4.ip_forward=1

初始化iptables

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 iptables-save –c

# Generated by iptables-save v1.4.21 on Thu Jul 17 01:37:57 2014

*nat

:PREROUTING ACCEPT [0:0]

:INPUT ACCEPT [0:0]

:OUTPUT ACCEPT [0:0]

:POSTROUTING ACCEPT [0:0]

COMMIT

# Completed on Thu Jul 17 01:37:57 2014

# Generated by iptables-save v1.4.21 on Thu Jul 17 01:37:57 2014

*mangle

:PREROUTING ACCEPT [0:0]

:INPUT ACCEPT [0:0]

:FORWARD ACCEPT [0:0]

:OUTPUT ACCEPT [0:0]

:POSTROUTING ACCEPT [0:0]

COMMIT

# Completed on Thu Jul 17 01:37:57 2014

# Generated by iptables-save v1.4.21 on Thu Jul 17 01:37:57 2014

*filter

:INPUT ACCEPT [0:0]

:FORWARD ACCEPT [0:0]

:OUTPUT ACCEPT [0:0]

COMMIT

# Completed on Thu Jul 17 01:37:57 2014

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 iptables-restore –c

啟動metadata proxy

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 neutron-ns-metadata-proxy --pid_file=/var/lib/neutron/external/pids/d62d417d-2005-46d7-a83b-b1e5c0a36d82.pid --metadata_proxy_socket=/var/lib/neutron/metadata_proxy --router_id=d62d417d-2005-46d7-a83b-b1e5c0a36d82 --state_path=/var/lib/neutron --metadata_port=9697 --debug --verbose --log-file=neutron-ns-metadata-proxy-d62d417d-2005-46d7-a83b-b1e5c0a36d82.log --log-dir=/var/log/neutron

檢視router的網路卡

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip -o link show qr-29003a09-e7

但是網路卡不存在

Device "qr-29003a09-e7" does not exist.

檢視br-int，router的網路卡會attach到這個網路卡上

ip -o link show br-int

58: br-int: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default

link/ether 0a:9b:c6:54:ef:46 brd ff:ff:ff:ff:ff:ff

建立router的網路卡，並且attach到br-int

ovs-vsctl -- --if-exists del-port qr-29003a09-e7 -- add-port br-int qr-29003a09-e7 -- set Interface qr-29003a09-e7 type=internal -
- set Interface qr-29003a09-e7 external-ids:iface-id=29003a09-e787-49dd-b5f4-11ad107159c7 -- set Interface qr-29003a09-e7 external-ids:iface-status=active -- set Interface qr-29003a09-e7 external-ids:attached-mac=fa:16:3e:84:6e:cc

設定router網路卡的mac

ip link set qr-29003a09-e7 address fa:16:3e:84:6e:cc

檢視所有的namespace

ip -o netns list

qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82

qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0

qrouter-26a45e0e-a58a-443b-a972-d62c0c5a1323

qdhcp-760d2c5e-4938-49b0-bffe-c77c5b141d18

有這個router的namespace

將這個網路卡放在這個namespace裡面

ip link set qr-29003a09-e7 netns qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82

將router的網路卡設為up

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip link set qr-29003a09-e7 up

檢視網路卡的地址

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip addr show qr-29003a09-e7 permanent scope global

設定網路卡的地址

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip -4 addr add 192.168.10.1/24 brd 192.168.10.255 scope global dev qr-2
9003a09-e7

檢視所有的網路卡

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip -o -d link list

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default

link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 promiscuity 0

241: qr-29003a09-e7: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default

link/ether fa:16:3e:84:6e:cc brd ff:ff:ff:ff:ff:ff promiscuity 1

(3) 建立外網，並且連線到router

neutron net-create public --router:external=True

neutron subnet-create --ip_version 4 --gateway $PUBLIC_GATEWAY public $PUBLIC_RANGE --allocation-pool start=$PUBLIC_START,end=$PUBLIC_END --disable-dhcp --name public-subnet

neutron router-gateway-set ${TENANT_ROUTER_NAME} public

檢視br-ex

ip -o link show br-ex

59: br-ex: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default

link/ether a0:48:1c:ab:df:b5 brd ff:ff:ff:ff:ff:ff

列出所有的網路卡

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip -o -d link list

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default

link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 promiscuity 0

241: qr-29003a09-e7: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default

link/ether fa:16:3e:84:6e:cc brd ff:ff:ff:ff:ff:ff promiscuity 1

檢視qg網路卡

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip -o link show qg-556ca938-e1

但是網路卡不存在

Device "qg-556ca938-e1" does not exist.

檢視br-ex

ip -o link show br-ex

建立新的網路卡qg，attach到br-ex

ovs-vsctl -- --if-exists del-port qg-556ca938-e1 -- add-port br-ex qg-556ca938-e1 -- set Interface qg-556ca938-e1 type=internal -- set Interface qg-556ca938-e1 external-ids:iface-id=556ca938-e11b-4246-bdc1-ef25c91b7593 -- set Interface qg-556ca938-e1 external-ids:iface-status=active -- set Interface qg-556ca938-e1 external-ids:attached-mac=fa:16:3e:68:12:c0

設定網路卡mac

ip link set qg-556ca938-e1 address fa:16:3e:68:12:c0

檢視所有的namespace

ip -o netns list

qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82

qdhcp-66b9930b-2871-414c-8c6f-991a6a8cffe0

qrouter-26a45e0e-a58a-443b-a972-d62c0c5a1323

qdhcp-760d2c5e-4938-49b0-bffe-c77c5b141d18

將qg網路卡設定到namespace中

ip link set qg-556ca938-e1 netns qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82

將網路卡設定為up

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip link set qg-556ca938-e1 up

檢視網路卡地址

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip addr show qg-556ca938-e1 permanent scope global

設定網路卡地址

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip -4 addr add 16.158.165.105/22 brd 16.158.167.255 scope global dev qg
-556ca938-e1

新增router表

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 route add default gw 16.158.164.1

設定iptables

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 iptables-save –c

# Generated by iptables-save v1.4.21 on Thu Jul 17 01:58:30 2014

*nat

:PREROUTING ACCEPT [4:425]

:INPUT ACCEPT [1:229]

:OUTPUT ACCEPT [0:0]

:POSTROUTING ACCEPT [0:0]

:neutron-l3-agent-OUTPUT - [0:0]

:neutron-l3-agent-POSTROUTING - [0:0]

:neutron-l3-agent-PREROUTING - [0:0]

:neutron-l3-agent-float-snat - [0:0]

:neutron-l3-agent-snat - [0:0]

:neutron-postrouting-bottom - [0:0]

[4:425] -A PREROUTING -j neutron-l3-agent-PREROUTING

[0:0] -A OUTPUT -j neutron-l3-agent-OUTPUT

[0:0] -A POSTROUTING -j neutron-l3-agent-POSTROUTING

[0:0] -A POSTROUTING -j neutron-postrouting-bottom

[0:0] -A neutron-l3-agent-PREROUTING -d 169.254.169.254/32 -p tcp -m tcp --dport 80 -j REDIRECT --to-ports 9697

[0:0] -A neutron-l3-agent-snat -jneutron-l3-agent-float-snat

[0:0] -A neutron-postrouting-bottom -j neutron-l3-agent-snat

COMMIT

# Completed on Thu Jul 17 01:58:30 2014

# Generated by iptables-save v1.4.21 on Thu Jul 17 01:58:30 2014

*mangle

:PREROUTING ACCEPT [4:425]

:INPUT ACCEPT [1:229]

:FORWARD ACCEPT [0:0]

:OUTPUT ACCEPT [0:0]

:POSTROUTING ACCEPT [0:0]

COMMIT

# Completed on Thu Jul 17 01:58:30 2014

# Generated by iptables-save v1.4.21 on Thu Jul 17 01:58:30 2014

*filter

:INPUT ACCEPT [1:229]

:FORWARD ACCEPT [0:0]

:OUTPUT ACCEPT [0:0]

:neutron-filter-top - [0:0]

:neutron-l3-agent-FORWARD - [0:0]

:neutron-l3-agent-INPUT - [0:0]

:neutron-l3-agent-OUTPUT - [0:0]

:neutron-l3-agent-local - [0:0]

[1:229] -A INPUT -j neutron-l3-agent-INPUT

[0:0] -A FORWARD -j neutron-filter-top

[0:0] -A FORWARD -j neutron-l3-agent-FORWARD

[0:0] -A OUTPUT -j neutron-filter-top

[0:0] -A OUTPUT -j neutron-l3-agent-OUTPUT

[0:0] -A neutron-filter-top -j neutron-l3-agent-local

[0:0] -A neutron-l3-agent-INPUT -d 127.0.0.1/32 -p tcp -m tcp --dport 9697 -j ACCEPT

COMMIT

# Completed on Thu Jul 17 01:58:30 2014

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 iptables-restore –c

顯示網路卡資訊

ip netns exec qrouter-d62d417d-2005-46d7-a83b-b1e5c0a36d82 ip addr show qg-556ca938-e1

242: qg-556ca938-e1: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default

    link/ether fa:16:3e:68:12:c0 brd ff:ff:ff:ff:ff:ff

    inet 16.158.165.105/22 brd 16.158.167.255 scope global qg-556ca938-e1

       valid_lft forever preferred_lft forever

    inet6 fe80::f816:3eff:fe68:12c0/64 scope link tentative

       valid_lft forever preferred_lft forever