[Samba] Joining Samba AD DC from Docker container fails - timeout

[Rowland penny]

On 15/06/2021 21:19, Greg Schaub via samba wrote:
> I have created a Docker container to support Samba Domain Controller
> services.  I am joining to an existing Samba DC that is running on a Debian
> based image.  I have successfully joined other DC's to this server in the
> past and have a set created documentation to help ensure it works properly
> in the future.
>
> The new server container is based on Ubuntu 20.04 and I built it through the
> distro packages.  I have configured Bind DLZ, sshd, and ntp which all appear
> to be working properly.  I can share the specific packages if necessary, but
> I would be surprised if I'm missing anything.  I have tried this both with
> and without smbd running.
>
> I saw in a prior post blocked ports can lead to this type of behavior.
> Therefore, I ran a port scan from the container to the source server and
> verified that all needed ports are open.  I also ran a port scan against the
> container which shows that ports 22 and 53 are open.  I also did this as the
> join process was running and interestingly (at least to me) no other ports
> were listening on the container at that time.  I cannot find any helpful
> logs except for the output here.  I do see bind activity between the servers
> in syslog while the join was running.
>
> I'm out of ideas at this point.  Not sure if this is a docker/container
> issue or a Ubuntu one.  For Ubuntu, this is the first time I have tried to
> join a DC from that distribution.  I have added the output of the latest
> join attempt below.
>
> Hope someone can point me in the right direction.
>
> Regards.Greg
>
> root at schaub-dc1:/var/lib/samba# samba-tool domain join home.theschaubs.com
> DC -U"HOME\administrator" --dns-backend=BIND9_DLZ --option='idmap_ldb:use
> rfc2307 = yes' --verbose


You need a lot more ports than 22 and 53 open, see here for a full list:

https://wiki.samba.org/index.php/Samba_AD_DC_Port_Usage

Is your container privileged ?

Rowland