Can I get ip address inside my docker container?

How to get container ip address inside this container?

'docker inspect $hostname ...' not suitable, because I don't share /var/run/docker.sock host file to container.

I can find the IP address with

hostname -i

Of course, that may not be completely accurate if there is more than one interface.

Edit

Note: According to the hostname man page, hostname -i uses DNS to resolve the ip address, where hostname -I displays all the addresses except loopback, does not depend on DNS, and is recommended.

In all my Docker containers, -i and -I return the same results (but this is not the case on my desktop).

As the IP address is in the first line of /etc/hosts, you can do in a container the awk command that prints the first word of the first line of /etc/hosts

$ awk 'END{print $1}' /etc/hosts
172.17.0.14

Why not something as simple as:

grep "`hostname`" /etc/hosts|awk '{print $1}'

or

grep "$HOSTNAME" /etc/hosts|awk '{print $1}'