当搭建完openstack之后,在创建instance之前,第一件事情就是创建network,一个经典的流程如下:

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) 创建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}')

当仅有private network的时候,会对这个private network创建一个DHCP Server

所以DHCP Agent会执行下面的命令:

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

这个命令试图从dhcp的namespace里面查找dhcp的网卡,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

于是试图创建dhcp server的网卡,这个网卡会attach到br-int上,所以先查看br-int

ip -o link show br-int

如果br-int没有问题,于是创建dhcp server的网卡,并且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

为网卡设置mac

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

查看当前存在的namespace

ip -o netns list

返回

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

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

发现没有这个dhcp所对应的namespace,需要创建一个

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

将io网卡设置为up

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

将新建的dhcp server的网卡放在这个namespace里面

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

将DHCP server的网卡设置为up

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

查看这个网卡的ip地址

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

为这个网卡配置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

第一个地址是dhcp server的地址,第二个地址是metadata server的地址

查看路由表

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

添加路由表

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

查看网卡的配置

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

启动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

启动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

最后查看一下网卡配置

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

kill -HUP 17666

这个PID是什么呢?

# 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

原来是我们的dhcp server

这个命令的作用是:如果想要更改配置而不需停止并重新启动服务,请使用该命令。在对配置文件作必要的更改后,发出该命令以动态更新服务配置。

最后查看一下路由配置

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

(2) 创建一个router,并且和private network相连

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

查看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

查看所有的namespace

ip -o netns list

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

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

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

发现没有这个router的namespace,创建一个

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

将io网卡设为up

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

这是一个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

启动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

查看router的网卡

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

但是网卡不存在

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

查看br-int,router的网卡会attach到这个网卡上

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

创建router的网卡,并且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

设置router网卡的mac

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

查看所有的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

有这个router的namespace

将这个网卡放在这个namespace里面

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

将router的网卡设为up

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

查看网卡的地址

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

设置网卡的地址

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

查看所有的网卡

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) 创建外网,并且连接到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

查看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

列出所有的网卡

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

查看qg网卡

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

但是网卡不存在

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

查看br-ex

ip -o link show br-ex

创建新的网卡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

设置网卡mac

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

查看所有的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

将qg网卡设置到namespace中

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

将网卡设置为up

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

查看网卡地址

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

设置网卡地址

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

添加router表

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

设置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

显示网卡信息

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

转自http://www.cnblogs.com/popsuper1982/p/3849822.html

neutron创建network执行的那些命令的更多相关文章

  1. 使用jar命令打jar/war包、创建可执行jar包、运行jar包、及批处理脚本编写

    jar 命令 jar 是一个jar.exe可执行命令,即可以生成jar文件,也可以生成war文件   使用示例:jar -cvf ../xxx.jar *  -c   create,创建新的归档文档 ...

  2. Neutron 理解 (1): Neutron 所实现的网络虚拟化 [How Neutron Virtualizes Network]

    学习 Neutron 系列文章: (1)Neutron 所实现的网络虚拟化 (2)Neutron OpenvSwitch + VLAN 虚拟网络 (3)Neutron OpenvSwitch + GR ...

  3. BSA Network Shell系列-nexec命令

    # nexec ## 1 说明:nexec是远程命令接口引擎 ,用于在远程主机执行命令 nexec [-?] [-t term] [-o] [-i] [-l] [-nohup hostname &qu ...

  4. Neutron vxlan network

    OpenStack 还支持 vxlan 和 gre 这两种 overlay network.   overlay network 是指建立在其他网络上的网络. 该网络中的节点可以看作通过虚拟(或逻辑) ...

  5. Neutron Vlan Network 学习

    vlan network 是带 tag 的网络,是实际应用最广泛的网络类型.    下图是 vlan100 网络的示例.   1. 三个 instance 通过 TAP 设备连接到名为 brqXXXX ...

  6. Neutron flat network 学习

    flat network 是不带 tag 的网络,要求宿主机的物理网卡直接与 linux bridge 连接,这意味着: 每个 flat network 都会独占一个物理网卡.   在 ML2 配置中 ...

  7. 创建maven项目(cmd 命令)

    2016五月 22 原 创建maven项目(cmd 命令) 分类:maven (994) (0) 1.普通方式创建 1)进入cmd窗口执行 mvn archetype:generate 2) 光标停止 ...

  8. (八)Eclipse创建Maven项目运行mvn命令

    1.Eclipse创建Maven项目 使用Eclipse创建一个Maven项目非常的简单,选择菜单项File>New>Other(也可以在项目结构空白处右击鼠标键),在弹出的对话框中选择M ...

  9. Neutron Vlan Network 原理- 每天5分钟玩转 OpenStack(92)

    前面我们陆续学习了 Neutron local network,flat network 和 DHCP 服务,从本节将开始讨论 vlan network. vlan network 是带 tag 的网 ...

随机推荐

  1. oracle中DDL DML指什么?

    DDL create table 创建表 alter table 修改表 drop table 删除表 truncate table 删除表中所有行 create index 创建索引 drop in ...

  2. malloc函数详解

    一.原型:extern void *malloc(unsigned int num_bytes); 头文件:#include <malloc.h> 或 #include <alloc ...

  3. uva 1658(最小费用最大流)

    题意:一个带权有向图,求起点到终点的两条路径权值之和最小,且两条路径没有公共点(除起点,终点): 分析:拆点法,将u拆成u和u',u-u'容量为1,费用为0,这样就能保证每个点只用一次,起点s-s'容 ...

  4. net中序列化读写xml

    参考http://www.cnblogs.com/fish-li/archive/2013/05/05/3061816.html 我们可以直接使用XmlTextReader.XmlDocument.X ...

  5. NetworkComms V3 之同时监听多端口

    NetworkComms网络通信框架序言 NetworkComms通信框架,是一款来自英国的c#语言编写的通信框架,历时6年研发,成熟稳定,性能可靠.   框架支持同时监听服务器上的多个端口,写法如下 ...

  6. JS只弹出一个居中弹出窗口

    var newWindow;//定义一个窗口,有利于窗口间的通讯function makeNewWindow(url) {   if (!newWindow || newWindow.closed) ...

  7. OC语言BLOCK和协议

    OC语言BLOCK和协议 一.BOLCK (一)简介 BLOCK是什么?苹果推荐的类型,效率高,在运行中保存代码.用来封装和保存代码,有点像函数,BLOCK可以在任何时候执行. BOLCK和函数的相似 ...

  8. 【BZOJ】2719 银河之星

    可以将棋子分为9种类型.且可以通过合并使得两个不同种类棋子转换为另一种棋子(不过要注意棋盘大小,有的时候硬要合并会到棋盘外面,可以先把棋盘全部转换,然后枚举每一个棋子的转换).然后把状态压成一个十位的 ...

  9. Object中的一些方法

    Object.create()参数为一个对象,创建一个对象,其原型为参数,如果为null,则无原型. Object.keys()参数为对象,返回一个数组,为对象中所有可枚举的自有属性 Object.g ...

  10. 使用 CSS 媒体查询创建响应式网站

    简介 现今每天都有更多的手机和平板电脑问市.消费者能够拥有可想象到的各种规格和形状的设备,但是网站开发人员却面临一个挑战:如何使他们的网站在传统浏览器.手机和平板电脑浏览器上有很好的效果,如何在各种大 ...