Useful information to have in the logs.
Mar 14 16:45:27 H systemd-portabled[510]: Successfully attached ephemeral '/usr/share/minimal_0.raw' and its extension(s) '/usr/share/app0.raw' using profile 'default'
Previously, if an [Address] section is configured with a null address,
e.g. Address=0.0.0.0/24, then we acquired a free address in
link_request_address().
With this commit, we queue a request with the null address as is, and
acquire a free address later in address_process_request(). Similary,
now IPv4ACD daemon is configured in address_process_request().
With this change, we can make the address acquisition depend on other
conditions, e.g. if the persistent storage is ready or not.
Otherwise, even if the persistent storage is not ready, the DHCP server
may be started e.g. by unplugging and plugging cable.
Follow-up for 5582b36c38.
From the outside it's difficult to determine whether (and when) the PID1
inside a container supports systemd's more complete set of UNIX process
signals or not. Let's make this easier, and simply send a notification
message when we are ready.
This new passive target is supposed to be pulled in by SSH
implementations and should be reached when remote SSH access is
possible. The idea is that this target can be used as indicator for
other components to determine if and when SSH access is possible.
One specific usecase for this is the new sd_notify() logic in PID 1 that
sends its own supervisor notifications whenever target units are
reached. This can be used to precisely schedule SSH connections from
host to VM/container, or just to identify systems where SSH is even
available.
Let's inform the the supervisor about various happenings of our service
manager, specifically the boot milestones we reach.
We so far have only a singular READY=1 message, to inform about bootup
completion. But sometimes it is interesting to have something for
finegrained, in particular something that indicates optional components
that have been activated.
Usecase for this: in a later PR I intend to introduce a generic
"ssh.target" that is supposed to be activated when SSH becomes available
on a host. A supervisor (i.e. a VMM/hypervisor/container mgr/…) can
watch for that, and know two things:
1. that SSH is generally available in the system
2. when it is available
In order to not flood the supervisor with events I only send these out
for target units. We could open this up later, in theory, but I think it
makes sense to tell people instead to define clear milestone target
units if they want a supervisor to be able to track system state.
Similar as the previous commit, it's useful for a supervisor to know
what machine ID we settlted on, in particular as various other things
are deterministically derived from it, for example MAC addresses and
such.
once we decided on a hostname, let's tell the supervisor about it. This
is useful for example in order to recognize the system via mDNS/LLMNR or
in a DHCP lease.
