initscripts

[Miloslav Trmač]

> and the main point is: there is no need to replace network.service on
> *any* static configured machine

(As a short-time initscripts comaintainer way-back-when:)  There may not be a need for anything smarter than init.d/network for machines with _trivial_ static configuration (a few interfaces with static IP addresses), but it starts breaking down very quickly with more complex setups.

Networking is inherently a DAG: IP alias ON TOP OF a bond ON TOP OF an Ethernet vlan ON TOP OF a vlan trunk connected through a physical cabe¹, and frequently when something changes in this DAG (change an IP alias, change bond composition, change vlan tag, change a performance tuning parameter) it would be useful to also update/refresh configuration of the other related components.  And building the kind of data structure necessary to keep track of these relationships is pretty much impossible in the shell language², so it hasn’t been done.  init.d/network more or less assumes that the complex cases don’t happen instead of supporting them properly.
    Mirek

¹ This may be a nonsensical example, it’s been about 8 years.  But I am confident about the gist of the issue.
² Well, after seeing ifup-aliases, my sense of what is “pretty much impossible in the shell language” has been dulled; but maintaining such relationships is another order of magnitude more complex than ifup-aliases, and given the speed of shell a shell daemon (☺) would be needed anyway just to amortize the overhead of dealing with the DAG.