用ovs-docker讓容器網絡支持Vlan隔離

參考文獻：
https://blog.csdn.net/canxinghen/article/details/50321573

docker原生使用linux bridge來創建網橋，這樣無法使用vlan對容器間的網絡進行網絡隔離。
openvswitch社區提供了一個工具ovs-docker來給docker快速搭建ovs網絡。

1、使用ovs創建網橋

ovs-vsctl add-br br0

2、創建3個容器，容器網絡模型設置爲none

2.1、拉取測試鏡像busybox

docker pull busybox:latest

2.2、創建容器

docker run -it -d --name routerA --net=none --privileged busybox
docker run -it -d --name routerB --net=none --privileged busybox
docker run -it -d --name routerC --net=none --privileged busybox

3、使用ovs-docker給容器添加網口

ovs-docker add-port br0 eth0 routerA --ipaddress=192.168.100.1/24
ovs-docker add-port br0 eth0 routerB --ipaddress=192.168.100.2/24
ovs-docker add-port br0 eth1 routerB --ipaddress=192.168.200.2/24
ovs-docker add-port br0 eth0 routerC --ipaddress=192.168.100.3/24

上面給容器routeB，添加了兩個網卡；

可見，通過ovs-docker 給容器添加網卡時，會在邏輯交換機上添加端口，在宿主機上添加接口信息

4、測試容器之間是否連通

5、設置vlan隔離

設置Vlan的參數爲：網橋名、容器內網口名、容器名、vlan號

ovs-docker set-vlan br0 eth0 routerA 100
ovs-docker set-vlan br0 eth0 routerB 100
ovs-docker set-vlan br0 eth1 routerB 200
ovs-docker set-vlan br0 eth0 routerC 203

6、測試是否連通呢？

7、ovs-docker原理介紹

ovs-docker簡單又好用，它的原理就是用netns和veth來作容器和ovs網橋間的橋接！

#!/bin/bash
 
#檢查對應的可執行程序有沒有在$PATH目錄下
#檢查的可執行程序有 ovs-vsctl、docker、uuidgen
search_path () {
    save_IFS=$IFS
    IFS=:
    for dir in $PATH; do
        IFS=$save_IFS
        if test -x "$dir/$1"; then
            return 0
        fi
    done
    IFS=$save_IFS
    echo >&2 "$0: $1 not found in \$PATH, please install and try again"
    exit 1
}
 
#給所有的ovs-vsctl命令增加超時時間
ovs_vsctl () {
    ovs-vsctl --timeout=60 "$@"
}
 
#每個容器是一個netns
#但是只有在 /va/run/netns 下面建立鏈接，才能將veth掛在到該netns裏面
#也只有了鏈接，才能用ip netns list查詢到
create_netns_link () {
    mkdir -p /var/run/netns
    if [ ! -e /var/run/netns/"$PID" ]; then
        ln -s /proc/"$PID"/ns/net /var/run/netns/"$PID"
        trap 'delete_netns_link' 0
        for signal in 1 2 3 13 14 15; do
            #在收到特定信號後，刪掉鏈接
            #這些信號有：程序退出、ctrl+c、進程被殺掉等
            trap 'delete_netns_link; trap - $signal; kill -$signal $$' $signal
        done
    fi
}
 
#刪除鏈接
delete_netns_link () {
    rm -f /var/run/netns/"$PID"
}
 
#從ovs的數據庫中查詢port
#查詢條件是在創建port的時候設進去的 external_ids 
get_port_for_container_interface () {
    CONTAINER="$1"
    INTERFACE="$2"
 
    PORT=`ovs_vsctl --data=bare --no-heading --columns=name find interface \
             external_ids:container_id="$CONTAINER"  \
             external_ids:container_iface="$INTERFACE"`
    if [ -z "$PORT" ]; then
        echo >&2 "$UTIL: Failed to find any attached port" \
                 "for CONTAINER=$CONTAINER and INTERFACE=$INTERFACE"
    fi
    echo "$PORT"
}
 
#給容器添加port，原理是創建一個veth，一端掛在ovs網橋上，一端設到netns裏面
add_port () {
    BRIDGE="$1"
    INTERFACE="$2"
    CONTAINER="$3"
 
    #參數驗證
    if [ -z "$BRIDGE" ] || [ -z "$INTERFACE" ] || [ -z "$CONTAINER" ]; then
        echo >&2 "$UTIL add-port: not enough arguments (use --help for help)"
        exit 1
    fi
 
    #獲取附加參數：ip地址、mac地址、網關信息、mtu信息
    shift 3
    while [ $# -ne 0 ]; do
        case $1 in
            --ipaddress=*)
                ADDRESS=`expr X"$1" : 'X[^=]*=\(.*\)'`
                shift
                ;;
            --macaddress=*)
                MACADDRESS=`expr X"$1" : 'X[^=]*=\(.*\)'`
                shift
                ;;
            --gateway=*)
                GATEWAY=`expr X"$1" : 'X[^=]*=\(.*\)'`
                shift
                ;;
            --mtu=*)
                MTU=`expr X"$1" : 'X[^=]*=\(.*\)'`
                shift
                ;;
            *)
                echo >&2 "$UTIL add-port: unknown option \"$1\""
                exit 1
                ;;
        esac
    done
 
    #查看對應容器的特定端口是否已經存在
    # Check if a port is already attached for the given container and interface
    PORT=`get_port_for_container_interface "$CONTAINER" "$INTERFACE" \
            2>/dev/null`
    if [ -n "$PORT" ]; then
        echo >&2 "$UTIL: Port already attached" \
                 "for CONTAINER=$CONTAINER and INTERFACE=$INTERFACE"
        exit 1
    fi
 
    #網橋不存在就創建網橋
    if ovs_vsctl br-exists "$BRIDGE" || \
        ovs_vsctl add-br "$BRIDGE"; then :; else
        echo >&2 "$UTIL: Failed to create bridge $BRIDGE"
        exit 1
    fi
 
    #通過docker inspect命令獲取容器的PID（netns的id）
    if PID=`docker inspect -f '{{.State.Pid}}' "$CONTAINER"`; then :; else
        echo >&2 "$UTIL: Failed to get the PID of the container"
        exit 1
    fi
 
    #爲後面將veth打入netns，需要建立鏈接
    create_netns_link
 
    #創建一個veth對，veth的名字用uuid，加了“_l”後綴的是掛在網橋上的，加了“_c”的是掛在容器內
    ID=`uuidgen | sed 's/-//g'`
    PORTNAME="${ID:0:13}"
    ip link add "${PORTNAME}_l" type veth peer name "${PORTNAME}_c"
 
    # 將“_l”掛到網橋上，掛時增加external_ids信息用於後面查找和刪除
    if ovs_vsctl --may-exist add-port "$BRIDGE" "${PORTNAME}_l" \
       -- set interface "${PORTNAME}_l" \
       external_ids:container_id="$CONTAINER" \
       external_ids:container_iface="$INTERFACE"; then :; else
        echo >&2 "$UTIL: Failed to add "${PORTNAME}_l" port to bridge $BRIDGE"
        ip link delete "${PORTNAME}_l"
        exit 1
    fi
 
    #拉起“_l”的veth端口
    ip link set "${PORTNAME}_l" up
 
    #將“_c”移到容器的netns裏面
    ip link set "${PORTNAME}_c" netns "$PID"
 
    #將“_c”改名爲用戶設置的接口名，例如ethx
    ip netns exec "$PID" ip link set dev "${PORTNAME}_c" name "$INTERFACE"
    ip netns exec "$PID" ip link set "$INTERFACE" up
 
    #設置mtu
    if [ -n "$MTU" ]; then
        ip netns exec "$PID" ip link set dev "$INTERFACE" mtu "$MTU"
    fi
 
    #設置ip
    if [ -n "$ADDRESS" ]; then
        ip netns exec "$PID" ip addr add "$ADDRESS" dev "$INTERFACE"
    fi
 
    #設置mac
    if [ -n "$MACADDRESS" ]; then
        ip netns exec "$PID" ip link set dev "$INTERFACE" address "$MACADDRESS"
    fi
 
    #設置網關
    if [ -n "$GATEWAY" ]; then
        ip netns exec "$PID" ip route add default via "$GATEWAY"
    fi
}
 
#根據添加port時的external_ids查詢port後刪除
del_port () {
    BRIDGE="$1"
    INTERFACE="$2"
    CONTAINER="$3"
 
    if [ "$#" -lt 3 ]; then
        usage
        exit 1
    fi
 
    PORT=`get_port_for_container_interface "$CONTAINER" "$INTERFACE"`
    if [ -z "$PORT" ]; then
        exit 1
    fi
 
    ovs_vsctl --if-exists del-port "$PORT"
 
    ip link delete "$PORT"
}
 
del_ports () {
    BRIDGE="$1"
    CONTAINER="$2"
    if [ "$#" -lt 2 ]; then
        usage
        exit 1
    fi
 
    PORTS=`ovs_vsctl --data=bare --no-heading --columns=name find interface \
             external_ids:container_id="$CONTAINER"`
    if [ -z "$PORTS" ]; then
        exit 0
    fi
 
    for PORT in $PORTS; do
        ovs_vsctl --if-exists del-port "$PORT"
        ip link delete "$PORT"
    done
}
 
#使用ovs的set port tag的方式設置vlan
set_vlan () {
    BRIDGE="$1"
    INTERFACE="$2"
    CONTAINER_ID="$3"
    VLAN="$4"
 
    if [ "$#" -lt 4 ]; then
        usage
        exit 1
    fi
 
    PORT=`get_port_for_container_interface "$CONTAINER_ID" "$INTERFACE"`
    if [ -z "$PORT" ]; then
        exit 1
    fi
    ovs_vsctl set port "$PORT" tag="$VLAN"
}
 
usage() {
    cat << EOF
${UTIL}: Performs integration of Open vSwitch with Docker.
usage: ${UTIL} COMMAND
 
Commands:
  add-port BRIDGE INTERFACE CONTAINER [--ipaddress="ADDRESS"]
                    [--gateway=GATEWAY] [--macaddress="MACADDRESS"]
                    [--mtu=MTU]
                    Adds INTERFACE inside CONTAINER and connects it as a port
                    in Open vSwitch BRIDGE. Optionally, sets ADDRESS on
                    INTERFACE. ADDRESS can include a '/' to represent network
                    prefix length. Optionally, sets a GATEWAY, MACADDRESS
                    and MTU.  e.g.:
                    ${UTIL} add-port br-int eth1 c474a0e2830e
                    --ipaddress=192.168.1.2/24 --gateway=192.168.1.1
                    --macaddress="a2:c3:0d:49:7f:f8" --mtu=1450
  del-port BRIDGE INTERFACE CONTAINER
                    Deletes INTERFACE inside CONTAINER and removes its
                    connection to Open vSwitch BRIDGE. e.g.:
                    ${UTIL} del-port br-int eth1 c474a0e2830e
  del-ports BRIDGE CONTAINER
                    Removes all Open vSwitch interfaces from CONTAINER. e.g.:
                    ${UTIL} del-ports br-int c474a0e2830e
  set-vlan BRIDGE INTERFACE CONTAINER VLAN
                    Configures the INTERFACE of CONTAINER attached to BRIDGE
                    to become an access port of VLAN. e.g.:
                    ${UTIL} set-vlan br-int eth1 c474a0e2830e 5
Options:
  -h, --help        display this help message.
EOF
}
 
#查看$PATH是否存在對應的命令
UTIL=$(basename $0)
search_path ovs-vsctl
search_path docker
search_path uuidgen
 
if (ip netns) > /dev/null 2>&1; then :; else
    echo >&2 "$UTIL: ip utility not found (or it does not support netns),"\
             "cannot proceed"
    exit 1
fi
 
if [ $# -eq 0 ]; then
    usage
    exit 0
fi
 
#根據輸入的參數決定動作
case $1 in
    "add-port")
        shift
        add_port "$@"
        exit 0
        ;;
    "del-port")
        shift
        del_port "$@"
        exit 0
        ;;
    "del-ports")
        shift
        del_ports "$@"
        exit 0
        ;;
    "set-vlan")
        shift
        set_vlan "$@"
        exit 0
        ;;
    -h | --help)
        usage
        exit 0
        ;;
    *)
        echo >&2 "$UTIL: unknown command \"$1\" (use --help for help)"
        exit 1
        ;;
esac

把上面的腳本，放到這個目錄下，就行
文件名是ovs-docker