OVN

ovn-kubernetes 提供了一個ovs OVN 網絡插件，支持 underlay 和 overlay 兩種模式。

• underlay：容器運行在虛擬機中，而ovs則運行在虛擬機所在的物理機上，OVN將容器網絡和虛擬機網絡連接在一起

• overlay：OVN通過logical overlay network連接所有節點的容器，此時ovs可以直接運行在物理機或虛擬機上

Overlay模式

配置master

# start ovn
/usr/share/openvswitch/scripts/ovn-ctl start_northd
/usr/share/openvswitch/scripts/ovn-ctl start_controller

# start ovnkube
nohup sudo ovnkube -k8s-kubeconfig kubeconfig.yaml -net-controller \
 -loglevel=4 \
 -k8s-apiserver="http://$CENTRAL_IP:8080" \
 -logfile="/var/log/openvswitch/ovnkube.log" \
 -init-master=$NODE_NAME -cluster-subnet="$CLUSTER_IP_SUBNET" \
 -service-cluster-ip-range=$SERVICE_IP_SUBNET \
 -nodeport \
 -nb-address="tcp://$CENTRAL_IP:6631" \
 -sb-address="tcp://$CENTRAL_IP:6632" 2>&1 &

配置Node

nohup sudo ovnkube -k8s-kubeconfig kubeconfig.yaml -loglevel=4 \
    -logfile="/var/log/openvswitch/ovnkube.log" \
    -k8s-apiserver="http://$CENTRAL_IP:8080" \
    -init-node="$NODE_NAME"  \
    -nodeport \
    -nb-address="tcp://$CENTRAL_IP:6631" \
    -sb-address="tcp://$CENTRAL_IP:6632" -k8s-token="$TOKEN" \
    -init-gateways \
    -service-cluster-ip-range=$SERVICE_IP_SUBNET \
    -cluster-subnet=$CLUSTER_IP_SUBNET 2>&1 &

CNI插件原理

ADD操作

• 從ovn annotation獲取ip/mac/gateway

• 在容器netns中配置接口和路由

• 添加ovs端口

ovs-vsctl add-port br-int veth_outside \
  --set interface veth_outside \
    external_ids:attached_mac=mac_address \
    external_ids:iface-id=namespace_pod \
    external_ids:ip_address=ip_address

DEL操作

ovs-vsctl del-port br-int port

Underlay模式

暫未實現。

OVN 安裝方法

所有節點配置安裝源並安裝公共依賴

sudo apt-get install apt-transport-https
echo "deb https://packages.wand.net.nz $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/wand.list
sudo curl https://packages.wand.net.nz/keyring.gpg -o /etc/apt/trusted.gpg.d/wand.gpg
sudo apt-get update

sudo apt-get build-dep dkms
sudo apt-get install python-six openssl python-pip -y
sudo -H pip install --upgrade pip

sudo apt-get install openvswitch-datapath-dkms -y
sudo apt-get install openvswitch-switch openvswitch-common -y
sudo -H pip install ovs

Master 節點安裝 ovn-central

sudo apt-get install ovn-central ovn-common ovn-host -y

Node 節點安裝 ovn-host

sudo apt-get install ovn-host ovn-common -y

參考文檔

• https://github.com/openvswitch/ovn-kubernetes