$ docker run -it debian
root@44dd2ec7f1fa:/# apt update ; apt install whois; mkpasswd --method=sha-512
Get:1 http://security.debian.org/debian-security buster/updates InRelease [65.4 kB]
Get:2 http://deb.debian.org/debian buster InRelease [121 kB]
Get:3 http://deb.debian.org/debian buster-updates InRelease [51.9 kB]
Get:4 http://security.debian.org/debian-security buster/updates/main amd64 Packages [284 kB]
Get:5 http://deb.debian.org/debian buster/main amd64 Packages [7907 kB]
Get:6 http://deb.debian.org/debian buster-updates/main amd64 Packages [10.9 kB]
Fetched 8441 kB in 2s (4134 kB/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
2 packages can be upgraded. Run 'apt list --upgradable' to see them.
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  whois
0 upgraded, 1 newly installed, 0 to remove and 2 not upgraded.
Need to get 77.8 kB of archives.
After this operation, 364 kB of additional disk space will be used.
Get:1 http://deb.debian.org/debian buster/main amd64 whois amd64 5.4.3 [77.8 kB]
Fetched 77.8 kB in 0s (1254 kB/s)
debconf: delaying package configuration, since apt-utils is not installed
Selecting previously unselected package whois.
(Reading database ... 6677 files and directories currently installed.)
Preparing to unpack .../archives/whois_5.4.3_amd64.deb ...
Unpacking whois (5.4.3) ...
Setting up whois (5.4.3) ...
Password:
$6$cdsuRi38$3Rxnsk1yvrU.TT4ybXe/c2MY8QuItqw7/ZaubTqUtBC.zVETEAzVq7AEbDFH.c0oeIBuAK3mOYo2JRtvXIKHq.