Category Archives: Ubuntu

Raspberry Pi, Server, Ubuntu

Teamviewer14 on a raspberry pi running ubuntu 18.04 64bit

You can install Teamviewer in text only mode – yes it will show the console on the remote connection!
You need to assign it to your Teamviewer account in this case as there is no way for it to show you a password…
It works fine in graphical mode too of course.

If you try to download and install Teamviewer on a 64bit aarm64 distribution, it will show you lot’s of dependencies that can’t be satisfied because of the missing armhf architecture.
But don’t fear, we can install them easily by just adding the architecture, similar to x64 and x86 based systems.

sudo apt update
sudo apt upgrade
sudo dpkg --add-architecture armhf
wget https://download.teamviewer.com/download/linux/teamviewer-host_armhf.deb
sudo apt install ./teamviewer-host_armhf.deb
sudo teamviewer setup

And that’s it already.
You get Teamviewer running on Ubuntu 18.04 aarm64 without the need for a graphical user interface at all.

Also try:

teamviewer info
teamviewer help
Ubuntu

Use spamassassin from fetchmail – no mta config, no procmail

Once you get it, you get it.

mda "/usr/bin/spamc -f -e /usr/sbin/sendmail -oi -f %F %T"

It’s really easy with the MDA option from fetchmail. I’m on ubuntu-18.04 but it works with similar versions and debian too. Make sure your version of fetchmail supports the MDA config option!

I will not cover how to install and configure spamassassin here, we assume it’s installed and has a basic working setup. Same for fetchmail of course. You can run fetchmail as a system service, call it from cron, have global or per user config, the only “magic” is to add the mda option like this to call spamassassin and have it deliver the mail locally afterwards:

poll mail.server.tld with proto whatever user remoteuser there with password "s3cr3t4ndS3cur3" is localuser here use ssl and fetchall mda "/usr/bin/spamc -f -e /usr/sbin/sendmail -oi -f %F %T"

As you can see, keep whatever your poll line looks like, just add the MDA option in the end like the example shows. It assumes your MTA comes with a sendmail compatible wrapper (most do, certainly postfix does).

Ubuntu

Enable TRIM (SSD) on encrypted (and/or) LVM volume

For it to work you need several adjustments, every layer needs to support TRIM, have the support enabled and pass the information down to the next, till it reaches the physical layer.

Lets start at the highest layer in the stack, the filesystem:
Edit /etc/fstab to include the discard mount option where needed (keep in mind that the FS needs to support it, ext4 does):

/dev/mapper/lvm_crypt /data           ext4    defaults,discard        0       2

Next comes the logical volume manager – which is optional and should by default be setup correctly already. Anyway check to be sure that you got the following line in /etc/lvm/lvm.conf:

issue_discards = 1

Last but not least we need to tell the encryption layer to issue the trim commands too. For this to work you need to edit /etc/crypttab to include the discard option:

lvm_crypt UUID=a-uuid-or-device-path none luks,discard

After having changed the crypttab (and lvm.conf) it is neccessary to update the initrd image for the changes to take effect (at next boot):

sudo update-initramfs -k all -c

Reboot and test if it’s working:

sudo fstrim /data

 

Ubuntu

XRDP connection error, gnome Vino security settings

After having installed the new Trusty 14.04 LTS release – finally, I came across a problem that showed to be caused by the “new” default security setting of Gnome Vino. I was no longer able to connect to the console through XRDP:

XRPD: Connection Log
Connection Log … error – problem connecting

Fix is simple:

user@localhost:~$ gsettings set org.gnome.Vino require-encryption false

Of course you need to enable desktop sharing, allow other users to view your desktop and require the user to enter a password when connecting in the preferences, like before.

After that, login again and you are able to connect to the console via XRDP again.