Hey, there!

There’s a chance that your remote-host image won’t sucessfully build.

Why?

Well, in the course we are using centos:latest, which at that point was centos:7. In September/2019, centos 8 was released, and it’s downloaded instead of the 7 version when you use “latest”

Resolution:

1 – Change the from instruction and point to centos 7

FROM centos:7

2- Keep using centos 8 and modify these lines:

Change this

RUN useradd remote_user && 
    echo "1234" | passwd remote_user  --stdin &&  # Passwd command is deprecated on centos:8
    mkdir /home/remote_user/.ssh && 
    chmod 700 /home/remote_user/.ssh

to this:

RUN useradd remote_user && 
    echo "remote_user:1234" | chpasswd && 
    mkdir /home/remote_user/.ssh && 
    chmod 700 /home/remote_user/.ssh

You could also see errors related to sshd-keygen. If so, just change this line from :

RUN /usr/sbin/sshd-keygen

to

RUN ssh-keygen -A