Hi,
for server systems it isn’t necessary to start a graphical user interface because they usually run headless.
Continue reading Linux/systemd: Set default runlevel to console
Category Archives: Debian
Linux: Load iptables/firewall rules at startup
Hi,
when you set up firewall rules by iptables these rule are not persistent. This means they are volatile and will be deleted at reboot time.
Continue reading Linux: Load iptables/firewall rules at startup
Linux: Use X11 forwarding with putty and su/sudo
Hi,
when you use X11 forwarding with PuTTY or ssh -X a TCP Socket is opened to which each user can connect. The connection to the X11 itself is protected by an authentification cookie.
Means when you add this cookie to the session launched by su you could use X11 forwarding.
An example. Connect to a linux machine as user michael (by putty or from another linux machine)
1 | michael@debdev ~ # ssh -X michael@debdev1 |
In the session of debdev1 list all xauth cookies.
1 2 | michael@debdev1 ~ # xauth listdebdev1/unix:10 MIT-MAGIC-COOKIE-1 7ea68cc88e74c1697aa6c757504fc0d7 |
Note: these cookies are stored the users home directory in file .Xauthority => ~/.Xauthority
Then switch to another user on this machine
1 | michael@debdev1 ~ # sudo su helena |
When you try to start a X11 client you got some errors like this
1 2 | helena@debdev1 ~ # xtermCan't connect to X11 window server using 'localhost:10.0' as the value of the DISPLAY variable. |
Then verify you already have a ~/.Xauthority file
1 | helena@debdev1 ~ # ls -l ~/.Xauthority |
If not create a new file
1 | helena@debdev1 ~ # touch ~/.Xauthority |
and add the authentification cookie
1 | helena@debdev1 ~ # xauth add debdev1/unix:10 MIT-MAGIC-COOKIE-1 7ea68cc88e74c1697aa6c757504fc0d7 |
Then you should be able to start X11 programs
Michael
Linux: Call a phone and play a message with asterisk
Hi,
asterisk is a complete VoIP/SIP solution but can also be used as a SIP client to send a prerecorded message. In this example I will use a Fritz!box as the upstream SIP Server for asterisk.
Continue reading Linux: Call a phone and play a message with asterisk
Linux: Install LAMP Stack on Debian 10 (Buster)
Hi ,
this post describes the steps to install a lamp stack on debian linux. This is the base for many content management systems like Joomla, WordPress or Drupal.
Continue reading Linux: Install LAMP Stack on Debian 10 (Buster)