Google Sanitizers and Fedora 25

Here’s a tip if you are using Fedora and trying to use one of the Google Sanitizers with clang and is having problems doing so. One of the common problems is not being able to find libclang_rt.asan-x86_64.a:

This can be resolved by simply installing the compiler-rt package:

Restoring click method behavior on Fedora 25 and libinput

Here’s a quick tip if you need to enable the Software Button Area behavior on an Apple macbook running Fedora 25:

Some comments about this:

  1. You have to run it after every reboot
  2. There’s, probably, a better way to do this. Per documentation, it should be possible to set it up permanently by creating a file on /etc/X11/xorg.conf.d however I did not manage to create a file that works so far.

References:

 

SonarQube 5.6 upgrade

Overall tips for upgrade a SonarQube instance from 5.4 to 5.6 LTS.

 

 

SonarQube database migration: MariaDB 5.5 to MySQL 5.7

Newer versions of SonarQube have stopped supporting MariaDB and you may need to switch to MySQL instead. While I’d rather use MariaDB, I understand that it is not within the supported matrix. Therefore I am documenting the steps here. The steps are focused on RHEL 7 (they probably would work on Centos 7 as well, but I did not test it).

Before start with this process, shutdown your SonarQube instance as well as any other analysis that may access the database.

The first step is to use mysqldump to create a backup of your MariaDB database:

After the backup is complete, shutdown and disable your MariaDB instance:

Then install MySQL 5.7 from Software Collections. The process is documented on this page. These steps are for 5.6, however, you can just replace 56 with 57 in all the steps and the result is the same.

With the new MySQL 5.7 installed and running, create the database:

In the MySQL sheel recreate the database with the same credentials and permissions as the old one:

Then you can recover the backup into the new MySQL 5.7 instance:

Now you can go to your SonarQube server and start it.

 

 

Consolidating multiple git repositories into a single one

Today I decided to reorganize my GitHub repository. In the past, I added a lot of learning projects there and as time passed by, it was growing considerably. Since I currently have some work-related projects there, I thought it deserved some reorganization.

My idea was to consolidate some of the larger projects I had into a single repository where each component is a sub-module of the project. This was a rather natural choice because most of those projects are written in Java and use Maven, therefore being very easy to refactor into a module-based project layout.

One requirement I had was that I wanted to retain the commit history. After looking at some solutions involving git’s submodule or subtree features, I found one that was fairly simple. The process couldn’t be simpler: you have to add the projects as remote to your new project and run a couple of commands to merge, move and commit the files.

Additionally, since my projects usually follow the same standard, it was quite simple to automate. After running the initial steps to configure the new (consolidated) repository, I was able to run the mass import using the following command line:

I was even able to import the old branches for each of the sub-components I wanted to merge.

 

Some messaging stuff

Just sharing some messaging tools I have been working with recently.

The first one is this performance test tool: msg-perf-tool. There’s no secret here: you run the tool and it does its best to bring your messaging system to its knees (though this may not be the correct way how to test it … check the testing tips on the Github page). For now it supports only AMQP, but Stomp and MQTT support is on the way. You can find rpms for RHEL/Centos (6 and 7) and Fedora (22, 23 and 24) for i686 and x86_64 on my Copr profile here.

The second one is a web page that can display the performance data stored on an ElasticSearch database and present it in a beautiful way. I call it messaging performance center. Here’s how it looks like:

messaging performance tool
mpt-perf-ui

Some bits are still in progress, but it’s functional.

Lastly, there’s litestomp. A C implementation of the Simple (or Streaming) Text Oriented Messaging Protocol. It was built on top of what-seems-to-be the now defunct libstomp project. There’s a couple of bugfixes, a simpler and higher level API for ease of use. Still a work in progress, but you can download the current rpms for RHEL/Centos (6 and 7) and Fedora (22, 23 and 24) for i686 and x86_64 from my Copr project page on this link.

VIL: Very Important Links (updated)

Just some important links that might be useful for others.

Ptrace is a linux syscall that allows you to manipulate process. It’s commonly used to implement debuggers, although you can do quite a lot of other interesting stuff with it:

This link shows how to prevent having to enter a password everytime your are managing your Linux VMs. This is pretty handy if you are using vagrant and/or creating/destroying a lot of them: