hydracz / simple-azure-cni-bash

A simple bash based CNI works to allocate Azure VNET IP and assign to your POD

simple-azure-cni-bash

A simple bash based CNI works to allocate Azure VNET IP and assign to your POD

I got lots of idea from s-matyukevich，

features:

1. to dynamically creates a new ip-config for your Pod, without pre-assigned to VM (Azure VNET CNI is doing this way, but waste a lot of IPs) since IP-CONFIG will be created during CNI ADD , this will take much longger time for POD coming up. we can not run multiple CNI ADD at same time. so we have to lock and create ip-config one by one, this even slower when create multiple Pod at same node
2. assign fixed IP when create new ip-config and assign static IP to a pod (by a annotation, just like calico does.)
3. maybe other....

how to use:

1. your Azure VM should enable Managed Identify and assign network contributor role to that this identity,

2. make sure jq / kubelet / azure-cli are installed

   • jq:

     yum install -y epel-release
     yum install -y jq

   • azure-cli: azure-cli-installation，

   • make sure /bin/jq, /bin/az, /bin/kubelet are present in you system and able to execute

3. install this CNI

   • node-ip-alloc:

     wget -O /opt/cni/bin/node-ip-alloc \
        https://raw.githubusercontent.com/hydracz/simple-azure-cni-bash/main/node-ip-alloc
     chmod +x /opt/cni/bin/node-ip-alloc

   • conflist file: upload to /etc/cni/net.d

    wget -O /etc/cni/net.d/10-azure.conflist \
       https://raw.githubusercontent.com/hydracz/simple-azure-cni-bash/main/09-cni.conflist 
   

   • by Default kubeadm will save kubelet.conf in /etc/kubernetes/kubelet.conf, you need to modify the cni conflist in case your kubelet.conf is in different places

    {
      "cniVersion":"0.3.0",
      "name":"azure",
      "plugins":[
        {
          "type": "node-ip-alloc",
          "kubeletconf":"/etc/kubernetes/kubelet.conf"
        }
      ]
    }

   • prepare env file: upload to /etc/kubernetes/centos-k8s-cluster.env: currently 3 madatory ENV has to be present for this CNI to allocate ip-config and ips. different node will have different settings. I'm currently using a terraform per node template to generate this env..

     # cat /etc/kubernetes/centos-k8s-cluster.env
     export NODE_NIC_NAME="k8s-master-0-nic"
     export NODE_SUBNET_CIDR="10.0.0.0/17"
     export NODE_RG_NAME="rg-centos-k8s-southeastasia"

4. to assign static ip to pod, you just need to annotate your pod with following:

   annotations:
     node-ip-alloc-ipv4-address: 10.0.0.0
     node-ip-alloc-method: static