I'm running a Discourse forum software container in an Ubuntu Server, I was able to login to container using the command.

sudo docker exec -it app bash

And then I've setup password for the root user, but the ssh is not working as expected always getting incorrect password.

SSH debug log

Set /proc/self/oom_score_adj to 0
debug1: rexec start in 5 out 5 newsock 5 pipe 7 sock 8
debug1: inetd sockets after dupping: 3, 3
Connection from ::1 port 45924 on ::1 port 22
debug1: Client protocol version 2.0; client software version OpenSSH_6.6.1p1 Ubuntu-2ubuntu2
debug1: match: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2 pat OpenSSH_6.6.1* compat 0x04000000
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2
debug1: permanently_set_uid: 105/65534 [preauth]
debug1: list_hostkey_types: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ssh-ed25519 [preauth]
debug1: SSH2_MSG_KEXINIT sent [preauth]
debug1: SSH2_MSG_KEXINIT received [preauth]
debug1: kex: client->server aes128-ctr [email protected] none [preauth]
debug1: kex: server->client aes128-ctr [email protected] none [preauth]
debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth]
debug1: SSH2_MSG_NEWKEYS sent [preauth]
debug1: expecting SSH2_MSG_NEWKEYS [preauth]
debug1: SSH2_MSG_NEWKEYS received [preauth]
debug1: KEX done [preauth]
debug1: userauth-request for user root service ssh-connection method none [preauth]
debug1: attempt 0 failures 0 [preauth]
debug1: PAM: initializing for "root"
debug1: PAM: setting PAM_RHOST to "localhost"
debug1: PAM: setting PAM_TTY to "ssh"
debug1: userauth-request for user root service ssh-connection method password [preauth]
debug1: attempt 1 failures 0 [preauth]
pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=localhost  user=root
debug1: PAM: password authentication failed for root: Authentication failure
Failed password for root from ::1 port 45924 ssh2
Excess permission or bad ownership on file /var/log/btmp
Connection closed by ::1 [preauth]
debug1: do_cleanup [preauth]
debug1: monitor_read_log: child log fd closed
debug1: do_cleanup
debug1: PAM: cleanup
debug1: Killing privsep child 32712

Please advise.

  • The ssh was already enabled the container, its a container running Discourse forum software, what I did was change the password for root user. root@forum:/# id uid=0(root) gid=0(root) groups=0(root) root@forum:/# passwd Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully root@forum:/# ssh localhost root@localhost's password: Permission denied, please try again. root@localhost's password:
    – Augustin
    Aug 26, 2015 at 21:10
  • For testing sake, what happens if you try to ssh in as a non-root user? Aug 26, 2015 at 21:24

2 Answers 2


The issue is fixed now.

seems to be an issue with Discourse SSH container configuration,

In /etc/ssh/sshd_config

PermitRootLogin without-password

I've changed it to

PermitRootLogin yes

#PermitRootLogin without-password

That fixed the issue.


You should use code markup for pasting in a log file, but from what I can tell:

sshd[32711]: debug1: PAM: password authentication
failed for root: Authentication failure Aug 26 20:32:29

Seems relevant. Are you sure you are using the correct password for the root user of your docker image?

Also, did you restart the sshd service (in the docker image) so that sshd_config is re-loaded?

  • Already tried restarting the ssh service and changing password, still no luck.
    – Augustin
    Aug 26, 2015 at 21:08

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .