Centos 7 vs ubuntu 18 missing /etc/ssh/sshd_config?

GeorgeL · June 4, 2018, 9:51pm

LXD noob who is trying to setup allowing SSH connections directly into my LXD guest containers for Ubuntu 18.04 and CentOS 7.5 but seems CentOS version has a missing /etc/ssh/sshd_config ? I am following info at https://stackoverflow.com/a/21874613/272648

on Ubuntu container

lxc exec ubuntu18 -- ls -alh /etc/ssh/        
total 596K
drwxr-xr-x  2 root root 4.0K Jun  4 20:16 .
drwxr-xr-x 87 root root 4.0K Jun  4 20:16 ..
-rw-r--r--  1 root root 541K Feb 10 02:31 moduli
-rw-r--r--  1 root root 1.6K Feb 10 02:31 ssh_config
-rw-------  1 root root  668 Jun  4 17:46 ssh_host_dsa_key
-rw-r--r--  1 root root  603 Jun  4 17:46 ssh_host_dsa_key.pub
-rw-------  1 root root  227 Jun  4 17:46 ssh_host_ecdsa_key
-rw-r--r--  1 root root  175 Jun  4 17:46 ssh_host_ecdsa_key.pub
-rw-------  1 root root  399 Jun  4 17:46 ssh_host_ed25519_key
-rw-r--r--  1 root root   95 Jun  4 17:46 ssh_host_ed25519_key.pub
-rw-------  1 root root 1.7K Jun  4 17:46 ssh_host_rsa_key
-rw-r--r--  1 root root  395 Jun  4 17:46 ssh_host_rsa_key.pub
-rw-r--r--  1 root root  338 Jun  4 20:16 ssh_import_id
-rw-r--r--  1 root root 3.2K May 22 10:54 sshd_config

on CentOS 7.5 container

lxc exec centos75 -- ls -alh /etc/ssh/
total 584K
drwxr-xr-x  2 root root 4.0K Jun  4 02:22 .
drwxr-xr-x 59 root root 4.0K Jun  4 17:55 ..
-rw-r--r--  1 root root 569K Apr 11 04:21 moduli
-rw-r--r--  1 root root 2.3K Apr 11 04:21 ssh_config

lxc list
+----------+---------+----------------------+-----------------------------------------------+------------+-----------+
|   NAME   |  STATE  |         IPV4         |                     IPV6                      |    TYPE    | SNAPSHOTS |
+----------+---------+----------------------+-----------------------------------------------+------------+-----------+
| centos75 | RUNNING | 10.71.164.168 (eth0) | fd42:769c:ebd9:a0f7:216:3eff:fefd:23a2 (eth0) | PERSISTENT | 1         |
+----------+---------+----------------------+-----------------------------------------------+------------+-----------+
| ubuntu18 | RUNNING | 10.71.164.145 (eth0) | fd42:769c:ebd9:a0f7:216:3eff:fe42:4ca8 (eth0) | PERSISTENT | 2         |
+----------+---------+----------------------+-----------------------------------------------+------------+-----------+

Am I missing a step ?

stgraber · June 4, 2018, 9:56pm

The Ubuntu cloud images include sshd by default, the CentOS images do not. yum install openssh or something along those lines should get CentOS into the same state as Ubuntu.

simos · June 4, 2018, 10:05pm

Also, that post on stackoverflow is about LXC, not LXD. See Comparing LXD vs. LXC for the differences.
An easy way to figure out whether a tutorial is about LXC or LXD, is when they use commands like lxc-start (with dash) (these are old LXC), or whether they use commands like lxc launch ubuntu: (with space) (these are the new LXD).

There are two main repositories with containers images, ubuntu: and images:. To see what’s in them, run lxc image list ubuntu: and lxc image list images:.

As you are learning, go through the posts at LXD 2.0: Blog post series [0/12] | Stéphane Graber's website to get a thorough idea on what you can do with LXD.

Also, see at The LXD tutorials of Simos for my entry-level tutorials.

GeorgeL · June 4, 2018, 10:05pm

@stgraber thanks openssh-server yum package is what i needed

lxc exec centos75 -- yum -y install openssh openssh-server
lxc exec centos75 -- systemctl enable sshd
lxc exec centos75 -- systemctl restart sshd
lxc exec centos75 -- systemctl status sshd
lxc exec centos75 -- sed -i 's|#Port 22|Port 522|' /etc/ssh/sshd_config
lxc exec centos75 -- grep Port /etc/ssh/sshd_config
lxc exec centos75 -- systemctl restart sshd
lxc exec centos75 -- systemctl status sshd

lxc exec centos75 -- grep Port /etc/ssh/sshd_config
Port 522
#GatewayPorts no

GeorgeL · June 4, 2018, 10:06pm

Thanks @simos yes it’s confusing for a noob so thanks for the pointing me in right direction

dabeegmon · June 4, 2018, 10:15pm

Similar problems here but I’m running on Debian (snap running lxd all on debian stretch running a debian stretch container).

root@debian-research1:~# ls -alh /etc/ssh/
total 576K
drwxr-xr-x 1 root root 294 Jun 2 23:09 .
drwxr-xr-x 1 root root 2.6K Jun 4 13:06 …
-rw-r–r-- 1 root root 541K Nov 18 2017 moduli
-rw-r–r-- 1 root root 1.7K Nov 18 2017 ssh_config
-rw------- 1 root root 227 Jun 2 23:09 ssh_host_ecdsa_key
-rw-r–r-- 1 root root 183 Jun 2 23:09 ssh_host_ecdsa_key.pub
-rw------- 1 root root 411 Jun 2 23:09 ssh_host_ed25519_key
-rw-r–r-- 1 root root 103 Jun 2 23:09 ssh_host_ed25519_key.pub
-rw------- 1 root root 1.7K Jun 2 23:09 ssh_host_rsa_key
-rw-r–r-- 1 root root 403 Jun 2 23:09 ssh_host_rsa_key.pub
-rw-r–r-- 1 root root 3.3K Mar 1 15:17 sshd_config

Not sure what’s causing the issues but on containers setup and started using lxd 2.xx I can used x2go to connect. Containers set up using lxd3.0 no dice - – absolutely can’t connect using x2go although I can connect using just ssh.