Category Archives: Technical Stuff

Compiling Git on CentOS 6

I recently had the need to compile Git on a CentOS 6 system, because the available version (v1.7.1) did not support the ls-remote command used  by the Jenkins Git plugin. The various posts I found via Google were missing a crucial prerequisite, hence this short post.

  • Uninstall old Git with
    yum remove git
  • Install required packages (for me!) with
    sudo yum install libcurl-devel zlib-devel asciidoc openssl-devel xmlto
    
  • Download source code from https://www.kernel.org/pub/software/scm/git
  • Extract source with
    gzip -dc <FILE> | tar -xvf -
  • Compilation and installation
    make configure
    ./configure --prefix=/usr
    make all
    sudo make install install-doc install-html

And that should be it.

Dave Farley: The Problem With Microservices

The definitive video on Microservices, as far as I’m concerned. No marketing bullshit, no misguided “stateless-hello world-crap”, but a concise and applicable set of criteria. It is also worth noting, that overall/in general Dave prefers a service-oriented monolithic architecture. I can’t express how great this video is to describe the real core of the idea of Microservices. Please take the time to watch!

Linux and the Speed of Innovation

Although I have been a Linux person since 1995, I have come to like FreeBSD a lot. Primarily because two of my major systems are based on it. As my firewall I have been using pfSense for a number of years, and for storage it is FreeNAS. And both have never let me down, neither in terms of stability nor regarding their functionality.

Now the company behind FreeNAS (iXsystems) has announced a while ago, that they will move to Linux as the underlying operating system for their future core product. I am not sure I welcome this change that much. I can understand that simply for available know-how iXsystems want to do this switch. Plus the hardware vendor support is obviously broader and the community also does their part in testing. But, with some level of exaggeration,  Linux (not the kernel but adjacent things like systemd) has become kind-of the JavaScript framework of *nix systems. What I mean by that is that I personally perceive the rate at which things are re-done as too high for my liking. Just like every year multiple JavaScript frameworks appear that do the same thing as twenty others, just differently.

While there is merit to improving things, stability is often more important. And stability not only means that things work as expected. But also the rate of change is a factor. If a new framework saves me 20% development time that sounds great. But in the enterprise evolution, and by that investment protection, is typically what gets you the much better ROI. Because the 20% development improvement are more than eaten up by effort in other areas (esp. operations).

Dave Farley: Continuous Integration vs Feature Branch Workflow

There seems to be, at least partly induced by the relatively powerful merge-capabilities of Git, a trend back to using feature branches in distributed development. Since most of the folks I heard supporting this, are not super-senior it appears that feature branches seem the more obvious choice. Dave Farley, who is basically one of the inventors of CI/CD makes a very compelling argument against features branches in this video. Please watch!

Installing MySQL 8.0.22 CE and phpMyAdmin 5.0.4 on Debian 10

Quite recently I had decided to set up a VM with a database server in my home lab. My preferred server OS is Debian Linux (esp. since Red Hat announced the end of CentOS) and I wanted a recent version of MySQL, together with phpMyAdmin of course.

The MySQL installation was done following the instructions from here. Please make sure to check the MySQL page for the current version of mysql-apt-config_x.x.x-x_all.deb. The version mentioned in the article as an example is outdated.

For phpMyAdmin I followed the instructions from Digital Ocean, since I have had good experiences with other such documents from them. That document is meant for MariaDB, so things should work. Of course, you need to adjust the database command from mariadb to mysql, but that wasn’t too hard :-).

What did  not work, though, was the command to create the pma user for phpMyAdmin, which created the following output:

mysql> GRANT SELECT, INSERT, UPDATE, DELETE ON phpmyadmin.* TO 'pma'@'localhost' IDENTIFIED BY 'PASSWORD';

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IDENTIFIED BY 'PASSWORD'' at line 1

The underlying reason is that MySQL 8 does not allow the implicit creation of users anymore. So you have to split the command into the creation and the grant of rights like this:

mysql> create user 'pma'@'localhost' IDENTIFIED BY 'PASSWORD';
Query OK, 0 rows affected (0.00 sec)

mysql> GRANT SELECT, INSERT, UPDATE, DELETE ON phpmyadmin.* TO 'pma'@'localhost';
Query OK, 0 rows affected (0.00 sec)

The rest of the preparation went smoothly and soon I was presented with the login screen. However, I could not log in, but got the following error:

mysqli_real_connect(): The server requested authentication method unknown to the client [caching_sha2_password]

This is caused by a change of the default authentication in MySQL. To go back to the old way for a particular user, you can issue the following command in MySQL:

mysql> alter user 'pma'@'localhost' identified with mysql_native_password by 'PASSWORD';

With that change I was able to log on the phpMyAdmin. It should be noted, though, that this change has security implications. So please check this article if that approach is ok for you.