Feature Request: re-configure networking at runtime based upon potential DataSource changes

This bug was originally filed in Launchpad as [LP: #1833755](https://bugs.launchpad.net/cloud-init/+bug/1833755)

Launchpad details

affected_projects = []

assignee = None

assignee_name = None

date_closed = None

date_created = 2019-06-21T19:30:45.671083+00:00

date_fix_committed = None

date_fix_released = None

id = 1833755

importance = wishlist

is_complete = False

lp_url = https://bugs.launchpad.net/cloud-init/+bug/1833755

milestone = None

owner = nacc

owner_name = Nish Aravamudan

private = False

status = triaged

submitter = nacc

submitter_name = Nish Aravamudan

tags = []

duplicates = []

_Launchpad user **Nish Aravamudan(nacc)** wrote on 2019-06-21T19:30:45.671083+00:00_

Use Case: In our cloud, the networking configuration can be modified by end-users (e.g. enabling IPv6, or a private network) after first boot. We do not currently have a means to leverage cloud-init to *only* reconfigure the network of a VM when the datasource's contents for a VM have changed. Would it be possible to add something like this? In principle, this might only allow for laying down a new configuration onto the VM, it does not need to apply the configuration (that's the OS' responsibility via reboot or otherwise).

No files, tests, or entry points are named. Start by tracing how cloud-init currently reads datasource contents and generates networking configuration, then identify how a change after first boot could be detected. Done means a defined mechanism can regenerate the VM's network configuration from changed datasource data without requiring cloud-init to apply it.

Written by the indexing model from the issue text.