Remote Command Execution with SaltStack

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....

 · 6 min · Benjamin Cane

Understanding a little more about /etc/profile and /etc/bashrc

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....

 · 3 min · Benjamin Cane

SSH: Disable Host Checking for Scripts & Automation

In the world of Cloud Servers and Virtual Machines scripting and automation are top priority for any sysadmin. Recently while I was creating a script that logged into another server via SSH to run arbitrary commands, I ran into a brick wall. $ ssh 192.168.0.169 The authenticity of host '192.168.0.169 (192.168.0.169)' can't be established. ECDSA key fingerprint is 74:39:3b:09:43:57:ea:fb:12:18:45:0e:c6:55:bf:58. Are you sure you want to continue connecting (yes/no)? To anyone who has used SSH long enough the above message should look familiar....

 · 2 min · Benjamin Cane

ssh-keygen: Creating SSH Private/Public Keys

Are you tired of trying to memorize tons of passwords on different systems? Or do you simply want to have a faceless user SSH between two systems without being asked for a password? Well you are in luck because today we will be covering SSH keys. SSH Servers have the ability to authenticate users using public/private keys. In the case of pass-phrase less keys this allows users to ssh from one system to another without typing a password....

 · 3 min · Benjamin Cane

How to force GPFS (or other tools) to connect via an alternate ssh port

Recently I have been playing with the Global Parallel File System, which is a clustered file system from IBM. When setting up a cluster you can configure GPFS to utilize SSH/SCP to send administrative tasks to the other nodes in the cluster. The problem I ran into was that in my environment I do not run SSH over port 22 (for various reasons I wont get into). Needless to say once I configured SSH to listen on an alternate port GPFS stopped working....

 · 3 min · Benjamin Cane