When DLE is restarted, do not lose clones
It's quite inconvenient that we lose all the close when restart is needed.
A restart is needed when:
- we need to change the config
- during upgrades
A restart might also happen unexpectedly (e.g., the machine rebooted).
In all these cases, we risk losing some important work. That's why thin clones need to survive DLE restarts (and machine reboots).
TODO / How to implement
- reload configuration #134 (closed)
- choose serialization format - 2
- handle an incoming signal - 2
- back up the state of running instances to file(?) on SIGUSR1 - 6
- clone wrapper list (including clones, sessions)
- instance status
- port pool
- restore the state of backup instances - 12
- read serialized data
- initialize the state
- handle running processes inside DLE - 4
- add a configuration option to ignore restore file - 1
- merge existing configuration parameters with new ones - 6
As a DLE admin, I can restart DLE not losing clones, so people do not lose their work.