Wordpress is the most popular CMS in the world, powering over 30% of all websites. It owes its popularity to easy of use and a huge number of plugins. The plugins make it possible to turn Wordpress into anything from personal blog a to e-shop. Like others of its kind, Wordpress generates the pages dynamically. In other words, everytime it is accessed, it loads data from database and uses PHP to create a page it serves the visitor. As a result, Wordpress load speed is slower a it requires more resources. That is important point too keep in mind, since over 40% of users leave a page if does not load within 3 seconds.
Caching
This is where caching comes into picture. It combines the speed of static sites with the robustness of Wordpress. Instead of generating page on every load, Wordpress saves the resulting page. Other visitors just see this pregenerated static page. This significantly improves Wordpress load speed and saves server resources. And when you post a new article or a comment, the cache is automatically invalidated. So, you don’t have to be afraid, that visitor will see an outdated version.
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I have been busy working on a new project for the past several weeks. It has finally reached a state, where I can publicly announce it. So without further ado, welcome Mariner, the command line torrent searcher:
I use torrents for downloading Linux distributions. The reason being, that it is usually faster and easier than digging for the ISOs on the official websites. Still, most torrent trackers are bloated, filled with ads and plagued by popup windows. I could do without those. All this has lead me to write Mariner. As you can see in the animation above, it is a simple command line aplication. It let’s you search for a torrent on multiple trackers at once and find the fastest one. Among other features, it allows you to see the torrent details, download them and directly open them in your torrent application. Moreover, it is asynchronous. That means, it is more responsive than your average web scraper.
Conclusion
If it piqued your interest, you can learn more about Mariner in documentation. Or, you could just check the project page. But if you are looking for a more automatic way to download torrents, check my torrentbox guide.
For the last couple years, mass surveillance has been on the rise. Both governments and private entities alike track our every move online. As a result, our privacy has increasingly eroded. Under such circumstances, it is ever more important to fight for our right for it. But the problem is, that majority of population seems apathetic to this. If you are one of such people, I recommend watching the following TED talk by Glenn Greenwald. It nicely sums up why privacy matters.
Why Privacy Matters by Glenn Greenwald
You might have noticed a new entry quietly appearing on the project page. So, let me introduce it to you. The new entrant is Blog Terminal, a Wordpress plugin for drawing a terminal-like box, complete with prompt. If you have read some of my other blog posts, Blog Terminal is what powers the terminal boxes in them. For the longest time I have used Post Terminal plugin by Brandon Griffith. But there were some things I did not like about it. Namely, it was not possible to draw a terminal without a prompt (for showing example configs). Furthermore, since it did not take advantage of many of the Wordpress APIs, the code was unnecessarily complicated. This made it hard to add new features. Therefore, I have decided to completely rewrite it.
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After a couple of busy weeks, I finally found myself with some free time. There were a couple of interesting game releases that I wanted to check out. Unfortunately, that did not go so well in OpenSuse, with Steam not working. I was welcomed by the following error:
symbol lookup error: /usr/lib/libxcb-dri3.so.0:
undefined symbol: xcb_send_request_with_fds
It seems that Steam does not work as smooth in OpenSuse as in Ubuntu. Luckily, the fix was quite easy. You can disable the library in question using an environment variable. So I just set it when launching Steam:
$ host +x
$ LIBGL_DRI3_DISABLE=1 steam
Once I did that, the Steam launched normally and updated itself. After that, the problem disappeared, therefore I could just can run Steam normally. Time to try out Shieldbreaker, the new Darkest Dungeon DLC, with Steam controler. If you still have trouble running Steam, this might help you. Meanwhile, here’s hoping that the Steam Linux Integration project comes to Opensuse as well, for a seamless Steam experience.
Vim does not need to be introduced. Due to its steep learning curve, it is often considered the bane of new Linux users. But once you get the hang of it, there’s no denying, that it’s a very powerful tool. In this post I would like to share some Vim tips, that I’ve learned over the years, that will improve your productivity. It is not aimed at Vim beginners. If you are just starting out with Vim, I recommend the excellent Byte of Vim by Swaroop C H.
Save file without sudo
I think we’ve all been in this situation - you make edits to some system configuration and when you try to save them, you realize you don’t have sufficient privileges. No need to worry, you can save it with sudo straight from Vim, using this command:
:w !sudo tee "%" > /dev/null
Since I find myself myself in such situations a lot, I have mapped it to :W command in my vimrc:
$ echo 'command W w !sudo tee % > /dev/null' >> .vimrc
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Due to its availability, Raspberry Pi is an ideal candidate to run a simple server. After the initial setup, it will use DHCP to connect to your network. That means, each time you restart the Pi or your router, it might end up with a different IP address. This not ideal, as you will need to take a note of the new IP to connect to your services. In order to avoid reconfiguring your computers all the time, you should assign your Raspberry Pi static IP. This post will show you how to do it for ethernet connection on Raspbian, but the steps are the same for a wireless connection. Start by connecting to your Pi. When you do, you can see the current network settings by running:
$ cat /etc/network/interfaces
It should look something like this:
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
iface eth0 inet dhcp
The entry you need to change is for the eth0 interface. That is the default ethernet adapter. In order to use a static IP, you have to provide IP address, network, network mask, broadcast and default gateway. So, let’s get them.
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Docker has become omnipresent in recent years. However, by default, it requires root privileges to run containers. Obviously, this is not good security-wise. But a simple change will allow you to run docker container as a regular user. In the examples below, I am using Ubuntu 17.04, but the commands should be the same for any Linux distribution.
Add user to docker group
First of all, what happens if you try to run docker without sufficient privileges? You can see the output below:
$ docker run hello-world
docker: Got permission denied while trying to connect to the Docker daemon
socket at unix:///var/run/docker.sock: Post https://%2Fvar%2Frun%2Fdocker.sock/v1.28/containers/create: dial unix /var/run/docker.sock: connect: permission denied.
See 'docker run --help'.
Docker allows users in docker group to run containers. You can check which users the group contains by running:
$ cat /etc/group | grep docker docker:x:140:
In the example above, the group does not include any users. Therefore, you need root privileges to run containers, as shown by the error above. This is the default setting. To add your user to the docker group, run this command:
sudo usermod -a -G docker user
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Managing Vim plugins can quickly get messy. Fortunately, there are several solutions to this problem. My favorite one is Pathogen by Tim Pope. It makes it easy to install plugins in their own private directories and automatically load them. And combining it with Git will make your Vim configuration easily portable across computers.
Install Pathogen
So how do we set it up? First of all, prepare a Git repository for your Vim plugins:
$ git init .vim
$ mkdir .vim/bundle
Next, get Pathogen. To makes things easier, we will add it as Git submodule:
$ git submodule add https://github.com/tpope/vim-pathogen bundle/pathogen
$ ln -s autoload bundle/pathogen/autoload
Furthermore, to enable Pathogen, you must add the following lines to your .vimrc:
execute pathogen#infect() syntax on filetype plugin indent on
Managing Vim plugins
Now you can happily start adding other plugins as submodules. Here is an example using Vim Sensible:
$ git submodule add https://github.com/tpope/vim-sensible bundle/vim-sensible
In order to update them later, just run:
$ git submodule update --remote --merge
Finally, if you ever need to delete them later, follow these steps:
$ git submodule init bundle/vim-sensible
$ git rm bundle/vim-sensible
$ rm -Rf .git/modules/bundle/vim-airline
$ git commit
Synchronize everything
Just one thing is missing to make the setup perfect. Ideally, your vimrc would be stored along with the plugins. I prefer dotfiles for the job. For it is simple and ready to install using pip. So let’s do that:
$ sudo pip install dotfiles
Then create a folder for your Vim configuration (which you can use for other configurations as well):
Finally, add the Vim configuration files:
$ dotfiles --add ~/.vimrc
$ dotfiles --add ~/.vim
Voilà. At last, you can keep the changes to your Vim settings and plugins safely versioned now. And to set them up on a new computer, you just need to clone the repository, install dotfiles and run:
Can’t get easier than that. Now, head over to see some of my Vim tips.
I’ve been thinking about switching to a rolling distribution on my working machine for quite some time. Because the packages in Ubuntu repositories are just too outdated for my needs and I want to save myself the headache of PPAs. And when Ubuntu announced dropping Unity in favor of Gnome, my mind was made up. I would use a rolling distro on my main computer and Ubuntu 16.04 elsewhere.
Unify package installation
In the end, I decided to go for OpenSuse. Since I use an Ansible playbook to setup my machines, it would take no time to have it up an running. Or so I thought. However, there was a little caveat. As my playbook used the apt module to install software, it would obviously not run on OpenSuse. Luckily, since the version 2.0, Ansible provides a platform-agnostic package manager module. It is called simply package. As a result, installing packages across different distributions is as easy as running:
---
- name: Install packages
become: yes
package:
name: git
state: present
Or is it? While it may work in the case of Git, not all packages have a same name in different Linux distributions. So you have to set up variables for those: First of all, defaults in vars/default.yml:
Then, for Debian family vars/Debian.yml
---
apache_package: apache2
And for Redhat family vars/Redhat.yml
---
apache_package: httpd
Afterwards, just include them in your tasks:
- include_vars: "{{ item }}"
with_first_found:
- "{{ ansible_os_family }}.yml"
- "default.yml"
- name: Install Apache
become: yes
package: name: "{{ apache_package }}"
state: present
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