求助：dockerfile报错

我只要运行docker build就会报错

sj@sj-Lenovo-Y520-15IKBN:~$ docker build -t hello-docker .

Sending build context to Docker daemon 1.473GB

Step 1/10 : FROM ubuntu ---> 16508e5c265d

Step 2/10 : MAINTAINER SJ ---> Using cache ---> 9793b5597c05

Step 3/10 : RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10 ---> Running in c321977f3fef

E: gnupg, gnupg2 and gnupg1 do not seem to be installed, but one of them is required for this operation

The command '/bin/sh -c apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10' returned a non-zero code: 255

怎么解决啊