docker build时报错"failed to create endpoint xxxx on network bridge: failed to add the host (veth999999) <=> sandbox (vetha8888888) pair interfaces: operation not supported"

答: 加载内核模块veth(CONFIG_VETH)

1. 检查内核模块是否被加载
   $ modinfo veth
2. 加载内核模块
   $ sudo modprobe veth