Below is the content of /etc/subuid on my system.
On host
#cat /etc/subuid
incgnito:100000:65536
$ id -u
1000
1000 is UID of user incgnito
Now as per above content, UID 0 on container should be mapped to UID 100000 on system, but after logging to container , I found UID 0 inside container is mapped to UID 1000 on my system.
On Container
# cat /proc/1/uid_map
0 1000 1
1 100000 65536
Can anyone help me to understand this concept?