it seems that sometimes, the child process signal gets handled
before the parent process signal. Systemd then ignores the
childs signal (finished reloading) and only after going into
reloading state because of the parent. this will never finish.
Instead, wait for the state to change to 'reloading' after sending
that signal in the parent, an only fork afterwards. This way
we ensure that systemd knows about the reloading before actually trying
to do it.
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Tested-By: Fabian Ebner <f.ebner@proxmox.com>
sd_notify is not synchronous, iow. it only waits until the message
reaches the queue not until it is processed by systemd
when the process that sent such a message exits before systemd could
process it, it cannot be associated to the correct pid
so in case of reloading, we send a message with 'MAINPID=<newpid>'
to signal that it will change. if now the old process exits before
systemd knows this, it will not accept the 'READY=1' message from the
child, since it rejects the MAINPID change
since there is no (AFAICS) library interface to check the unit status,
we use 'systemctl is-active <SERVICE_NAME>' to check the state until
it is not 'reloading' anymore.
on newer systemd versions, there is 'sd_notify_barrier' which would
allow us to wait for systemd to have all messages from the current
pid to be processed before acknowledging to the child, but on buster
the systemd version is to old...
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
instead of await'ing the result of 'create_service' directly,
poll it together with the shutdown_future
if we reached that, fork_restart the new daemon, and await
the open future from 'create_service'
this way the old process still handles open connections until they finish,
while we already start a new process that handles new incoming connections
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
We get the path to our executable via a readlink() on
"/proc/self/exe", which appends a " (deleted)" during
package reloads.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
To ensure the new process' parent is pid 1, so systemd won't
complain about supervising a process it does not own.
Fixes the following log spam on reloads:
Apr 25 10:50:54 deb-dev systemd[1]: proxmox-backup.service: Supervising process 1625 which is not our child. We'll most likely not notice when it exits.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Now that we let hyper shutdown gracefully we need an owned
version of the listening socket to prevent it from closing
before running the reload preparations.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Reloadable resources are now 'Reloadable' instead of
'ReexecContinue'.
The struct handling the reload is a 'Reloader', not a
'ReexecStore'.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Proxy and daemon for now just want to handle reload via
`SIGHUP`, so provide a helper creating the signalfd stream
doing that - this is simply a filtered stream which passes
the remaining signals through, so it can be used exactly
like the signalfd stream could before to add more signals.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
