http://stackoverflow.com/questions/26021181/not-enough-entropy-to-support-dev-random-in-docker-containers-running-in-boot2d
-v /dev/urandom:/dev/random

https://github.com/ewindisch/docker-rngd/blob/master/Dockerfile
rng-tools:
CMD ["rngd", "-f", "-r", "/dev/hwrng", "-o", "/dev/random"]


# pgp --gen-key
...


# gpg -k
/root/.gnupg/pubring.gpg
------------------------
pub   2048R/0149AC94 2015-09-21
uid                  netlib
sub   2048R/92061E42 2015-09-21


export:
https://fedoraproject.org/wiki/Creating_GPG_Keys
gpg --export-secret-keys --armor netlib > /netlib-privkey.asc
gpg --export --armor netlib > /netlib-pubkey.asc


docker cp <container-id>:/netlib-privkey.asc -
docker cp <container-id>:/netlib-privkey.asc c/Users/<user-name>/<file>


import:
http://irtfweb.ifa.hawaii.edu/~lockhart/gpg/

gpg --allow-secret-key-import --import /netlib-privkey.asc
gpg --allow-secret-key-import --import --armor /netlib-privkey.asc

seems to be not needed:
gpg --import netlib-pubkey.asc
gpg --import --armor netlib-pubkey.asc