Archive

Archive for the ‘ubuntu’ Category

[mongodb] invalid GPG signatures

February 8, 2018 Leave a comment

Problem
I have an Ubuntu 14.04 LTS box with MongoDB. When I tried to update the packages, I got a similar error:

W: GPG error: http://repo.mongodb.org trusty/mongodb-org/3.2 Release: The following signatures were invalid: BADSIG D68FA50FEA312927 MongoDB 3.2 Release Signing Key 
WARNING: The following packages cannot be authenticated!
mongodb-org-shell mongodb-org-server mongodb-org-mongos mongodb-org-tools mongodb-org E: There are problems and -y was used without --force-yes

Solution

sudo apt-key list | \
 grep "expired: " | \
 sed -ne 's|pub .*/\([^ ]*\) .*|\1|gp' | \
 xargs -n1 sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys

Full explanation of this is here. In a nutshell: update expired keys from Ubuntu key server.

Advertisements

Install the Numix theme and icons for Ubuntu 16.04

November 24, 2017 Leave a comment

The look and feel of Ubuntu is quite boring. It looks the same with every release. If you want a fresh look, check out the Numix theme, it looks great.

Installation instructions are here.

Here is a screenshot of my desktop. I use the Numix Circle icons.

Update (20171126): I also updated my Manjaro box. You can customize the look and feel with the Xfce Theme Manager. Here is my current setting: Themes: Vertex; Windows Borders: Numix-Manjaro; Controls: Vertex; Icons: Numix Circle; Cursors: aero-drop. With “yaourt numix” and “yaourt numix circle” you can find easily what packages to install. I wanted to go full Numix, but then my Firefox looked ugly: the title of the tabs and the texts in the popups were unreadable, so I had to mix the themes Numix and Vertex to get a good result.

Categories: ubuntu Tags: , , ,

Introduction to Linux

September 23, 2017 Leave a comment

I want to start a new video series entitled “Introduction to Linux”. It is intended for beginners who never (or not much) used Linux before. So far I have one video, but I plan to add more videos in the future. I will update this post with the new videos.

Complete playlist: here.

Videos in the series:

Categories: linux, ubuntu Tags: ,

a new range of shortcuts with the Hyper key

February 9, 2017 Leave a comment

On the YouTube channel of gotbletu I found a very nice trick (video). It explains how to replace the Caps Lock with the so-called Hyper key. And why? Because Caps Lock is pretty useless and you cannot use it for shortcuts. But if you tell the system that at the place of Caps Lock there is another key, namely the Hyper key, then you can use a new range of shortcuts.

You can find my .Xmodmap file here. Just put it in your HOME folder and upon the next reboot it’ll be activated automatically. To activate it without a reboot, use the command “xmodmap ~/.Xmodmap“.

Then, under Manjaro (XFCE), go to the Start menu, start typing “keyboard”, and open the Keyboard application. Go to the “Application Shortcuts” tab and add some new shortcuts. This time, when you press Caps Lock, it’ll be recognized as the Hyper key. I added these:

Hyper + g    gedit
Hyper + k    konsole
Hyper + f    file browser (thunar)

Update (20170416)
Under Manjaro I had to create the .Xmodmap file and it is read automatically at each boot. However, under Ubuntu it’s not the case. I tried several methods and here is what worked for me: add “xmodmap ~/.Xmodmap” to the end of your ~/.bashrc file. Now, when you open a terminal, it’ll be activated for sure.

Music video

And if Hyper Hyper, then Scooter, of course:

Ubuntu: assign a better screenshot tool to the Print button

September 5, 2016 Leave a comment

Problem
The Ubuntu default screenshot tool (gnome-screenshot) is lame. In Manjaro there is a better tool called xfce4-screenshooter, which allows you to select a region, open it with Gimp, upload to Imgur, etc.

How to assign xfce4-screenshooter to the Print button?

Solution
First, install the software (sudo apt install xfce4-screenshooter). Then, open System Settings, select Keyboard, and go to the Shortcuts tab. Here ignore the “Screenshots” entry and select Custom Shortcuts. Click on the “+” sign and add the command xfce4-screenshooter. As a result, a new entry will appear. Click on its right side and assign the Print button to it. It’ll complain a bit but click on Re-assign. Done.

I found this nice solution here: http://askubuntu.com/a/609060/53599 . Click on this link for screenshots.

Categories: manjaro, ubuntu Tags: ,

how to configure a Digital Ocean Ubuntu 16.04 box

August 4, 2016 Leave a comment

I’ve updated my Digital Ocean Notes on GitHub. Now it includes information about configuring an Ubuntu 16.04 box.

Categories: ubuntu Tags: , ,

systemd notes

August 3, 2016 Leave a comment
Categories: ubuntu Tags: ,