Network configuration ENI (legacy)

Cloud-init supports reading and writing network config in the ENI format which is consumed by the ifupdown tool to parse and apply network configuration.

As an input format this is legacy. In cases where ENI format is available and another format is also available, cloud-init will prefer to use the other, newer format.

This can happen in either NoCloud or OpenStack datasources.

Please reference existing documentation for the /etc/network/interfaces(5) format.