/ Register

Get the most out of your Centmin Mod LEMP stack
Become a Member

Sysadmin exit dmotd.sh depending on connecting IP

Discussion in 'System Administration' started by jcat, Jul 22, 2020.

Previous Thread Next Thread
Loading...
  1. Jul 22, 2020 #1
    jcat

    jcat Member

    153
    22
    18
    Jun 21, 2015
    New Jersey
    Ratings:
    +64
    Local Time:
    12:55 PM
    We are trying to think of the best way to bypass
    Code:
    /usr/local/src/centminmod/config/motd/dmotd.sh
    when connecting to the server from a specific IP. When we deploy changes with Ansible the motd greatly delays the entire process so was thinking of adding something simple like

    Code:
    [[ $SSH_CONNECTION == *"123.123.123.123"* ]] && exit 0
    to the top of dmotd.sh

    Works good, anyway to make this work without having to modify centmin core files?
     
  2. Jul 22, 2020 #2
    jcat

    jcat Member

    153
    22
    18
    Jun 21, 2015
    New Jersey
    Ratings:
    +64
    Local Time:
    12:55 PM
    Ha nevermind, guess I just need to read.

    Code:
    echo "PrintMotd no" >> /etc/ssh/sshd_config
echo "# session optional pam_motd.so" >> /etc/pam.d/login
echo "/usr/local/bin/dmotd" >> /etc/profile
chmod +x /usr/local/bin/dmotd
    :D
     
  3. Jul 22, 2020 #3
    jcat

    jcat Member

    153
    22
    18
    Jun 21, 2015
    New Jersey
    Ratings:
    +64
    Local Time:
    12:55 PM
    Nevermind again
    Code:
    # ls -lh /usr/local/bin/dmotd
lrwxrwxrwx 1 root root 46 Jul 21 13:37 /usr/local/bin/dmotd -> /usr/local/src/centminmod/config/motd/dmotd.sh
    Looks like its a symlink so cannot make direct changes to /usr/local/bin/dmotd
     
  4. Jul 22, 2020 #4
    eva2000

    eva2000 Administrator Staff Member

    54,352
    12,198
    113
    May 24, 2014
    Brisbane, Australia
    Ratings:
    +18,763
    Local Time:
    3:55 AM
    Nginx 1.27.x
    MariaDB 10.x/11.4+
    Centmin Mod 123.09beta01 and higher's dmotd routine should now only trigger for interactive ssh sessions and not for non-interactive via login in /etc/profile.d/dmotd.sh.

    /etc/profile.d/dmotd.sh is populated from inc/motd.inc line 13-25 in 123.09beta01

    from /etc/profile.d/dmotd.sh
    Code (Text):
    #!/bin/bash
#if [[ "$(id -u)" = '0' && -f /usr/local/bin/dmotd ]]; then  /usr/local/bin/dmotd; fi
if tty -s; then type='interactive'; if [[ "$(id -u)" = '0' && -f /usr/local/bin/dmotd ]]; then /usr/local/bin/dmotd; fi; else type='non-interactive'; fi;
if echo $0 | grep -e ^\- 2>&1 > /dev/null; then login='login'; else login='non-login'; fi;
#echo "$type/$login"

    actual line above then triggers /usr/local/bin/dmotd
    Code (Text):
    if tty -s; then type='interactive'; if [[ "$(id -u)" = '0' && -f /usr/local/bin/dmotd ]]; then /usr/local/bin/dmotd; fi; else type='non-interactive'; fi;

    I guess you can change the logic for
    Code (Text):
    if [[ "$(id -u)" = '0' && -f /usr/local/bin/dmotd ]]

    to
    Code (Text):
    if [[ $SSH_CONNECTION != "123.123.123.123" && "$(id -u)" = '0' && -f /usr/local/bin/dmotd ]]

    or change $SSH_CONNECTION check against a file that contains a bunch of IP addresses if you have more than one IP address to account for.
     
Previous Thread Next Thread
Loading...

.