A few weeks back I wrote an article Getting started with SaltStack; that article covered Configuration and Package Automation with Saltstack. In Today's article I am going to cover SaltStack's Remote Execution abilities, a feature that I feel Saltstack has implemented better than other automation tools.
Running a command in a State If you remember from the previous article SaltStack's states are permanent configurations. Adding a command in a Salt state is used when you want to have a command that is run after provisioning a server, run every time Salt manages the state of the system or run when certain conditions are true.
Recently I was working on an issue where an application was not retaining the umask setting set in the root users profile or /etc/profile. After looking into the issue a bit it seemed that the application in question only applied the umask setting that was set in /etc/bashrc and would not even accept the values being the applications own start scripts.
After doing a bit of researched I learned a little bit more about what exactly these files do, the differences between them and when they are executed.
Systems Administration is changing, with the huge scale of internet company deployments and the popularity of cloud computing. Server deployments are often scaling faster than the systems administration teams supporting them. In order to meet the demand those teams are finding themselves changing the ways they have traditionally managed servers.
One of those changes is automation, where once a sysadmin would need to spend time installing packages by hand (via apt or yum) and modifying configuration files.
Backups are important, whether you are backing up your databases or your wedding pictures. The loss of data can ruin your day. While there is a huge list of backup software to choose from; some good, some not so good. One of the tools that I have used for years is rdiff-backup.
rdiff-backup is a rsync delta based backup tool that both stores a full mirror and incremental changes. It determines changes based on the rsync method of creating small delta files, which allows for rdiff-backup to restore files to any point in time (within the specified retention period).
MySQL is the most popular open source relational database management system (RDBMS) in the world. MySQL is used by everyone from the simple small business website to the large internet giants like Facebook, Google or Amazon. In fact the contents of this page are even stored within MySQL.
Installing MySQL is a fairly common task for any systems administrator; especially if that administrator is running a standard LAMP stack (Linux, Apache, MySQL & PHP/Python/Perl).