Ubuntu Core: how the file-system works

[Mark Shuttleworth]

On 20/01/17 06:33, Luca Dionisi wrote:
> Since my "thingy" is going to sport an experimental routing protocol,
> I need
> to change some files on the fly. For instance /etc/iproute/rt_tables. Which
> I already see that is not writeable in my Ubuntu Core install.
>
> Also I am going to use some commands that I haven't yet tested on Ubuntu
> Core. Mostly "ip" and "iptables", also in non-default network namespaces.
> And I don't know if they need internally write-access to some file.
>
> Do you see anything about it that would be infeasible in a Ubuntu Core as
> it currently stands?

That all sounds like stuff we would want to be doable. There are a
number of folks using Ubuntu Core for networking kit, so we are adding
capabilities for that domain all the time. We just recently added
network namespace control.

Generally, you want to think about how best to express config in a way
that easily survives upgrades. Editing something like rt_tables should
be fine. But where you have something that multiple pieces want to edit,
or a set of things which need to line up, we need to design a config
item which drives those things consistently so the device can *never*
end up in a broken state, by design. Make sense?

Mark