The upstream Istio CNI plugin supports running only one instance of the plugin on one node. To support soft multitenancy, it must be possible to install multiple instances of the plugin.

Because all the plugin related files are in two shared directories on the host's file system, we need to prefix the individual binaries and config files with the mesh namespace.

There are four files that need to be prefixed:

• /etc/cni/multus/net.d/istio-cni.conf
• /etc/cni/multus/net.d/istio-cni.kubeconfig
• /opt/cni/bin/istio-cni
• /opt/cni/bin/istio-iptables.sh

Although the istio-cni binary and the istio-iptables.sh script could be shared among multiple control planes if they use the same Maistra version, it's simpler to just have multiple files and prefix them with the mesh namespace instead of e.g. adding the version information into the file name.