Popcorn requires UUIDs (Universally unique IDs) so that it doesn’t receive submissions from the same system again before a certain period of time.
We used to use smolt id, but smolt package is not present in all Linux distributions.
So on a quest to find a universally unique ID that is present on all distributions, Petr Uzel pointed me to Lennart’s Blog Post.
tl;dr use/var/lib/dbus/machine-id if you are looking for a globally unique id for a Linux system.
- /sys/class/dmi/id/product_uuid: mainboard uuid
- CPUID/EAX=3: CPU serial number
- /sys/class/net/*/address: One or more network MAC addresses
- /sys/bus/usb/devices/*/serial:Serial numbers of various USB devices
The problems with hardware IDs are that:
- They are bound to specific, replaceable hardware
- Not universally available
- Filled with bogus data/random in virtual environments
- /proc/sys/kernel/random/boot_id: Random ID unique for each boot
- /var/lib/dbus/machine-id: identifies specific Linux installation.
- Doesn’t change if hardware is replaced
- Reliable in virtualized environments
- Globally unique
- /proc/self/sessionid: identifies a specific login session, maintained by kernel and shared by each process of a session. In some distributions this is always(uint32_t) -1
- getuid(): To identify a particular user. Locally unique, may be reassigned to new user if users are deleted.
We can combine locally unique ids with /var/lib/dbus/machine-id to generate globally unique ids for a particular user or session.
You can also generate UUIDs using uuidgen command or simply read 16 bytes from /dev/random