System administration is a special are of IT. It also has a special place in my heart. It is an interesting mixture of all the other disciplines, both common across the whole industry, and at the same time unique for each person, company, and geographical location. When I have something to say or share about system administration, I use this category.
Doug Vitale Tech Blog runs a post with a collection of the deprecated Linux networking commands and their replacements. Pretty handy if you want update some of your old bash scripts.
Deprecated command Replacement command(s) arp ip n (ip neighbor) ifconfig ip a (ip addr), ip link, ip -s (ip -stats) iptunnel ip tunnel iwconfig iw nameif ip link, ifrename netstat ss, ip route (for netstat-r), ip -s link (for netstat -i), ip maddr (for netstat-g) route ip r (ip route)
CSV, or comma-separated values, is a very common format for managing all kinds of configurations, as well data manipulation. Â As the linked Wikipedia page mentions, there are a few RFCs that try to standardize the format. Â However, I thought, there is still a lack of schema-type standard that would allow one to define a format for particular file.
Today I came across an effort that attempts to do just that –Â CSV Schema Language v1.1 – an unofficial draft of the language for defining and validating CSV data. Â This is work in progress by the Digital Preservation team at The National Archives.
Apart from the unofficial draft of the language, there is also an Open Source CSV Validator v1.1 application, written in Scala.
Federacy has an interesting research in Docker image vulnerabilities. Â The bottom line is:
24% of latest Docker images have significant vulnerabilities
This can and should be improved, especially given the whole hierarchical structure of Docker images. Â It’s not like improving security of all those random GitHub repositories.
In “Why Configuration Management and Provisioning are Different” Carlos Nuñez advocates for the use of specialized infrastructure provisioning tools, like Terraform, Heat, and CloudFormation, instead of relying on the configuration management tools, like Ansible or Puppet.
I agree with his argument for the rollbacks, but not so much for the maintaining state and complexity. Â However I’m not yet comfortable to word my disagreement – my head is all over the place with clouds, and I’m still weak on the terminology.
The article is nice regardless, and made me look at the provisioning tools once again.
Here are a couple of useful Bash resources that came upon my radar recently.
First one is Julia Evans’ blog post “Bash scripting quirks & safety tips“.  It’s quite introductory, but is has a few useful tips.  The one in particular I either didn’t know about or completely forgot mentioned recently is on how to make Bash scripts safer by using “set -e“, “set -u“, and “set -o pipefail“.  These go well with another post of mine not so long ago.
The second is Sam Rowe’s blog post “Advancing in the Bash Shell“, which I found useful for all kinds of navigation and variable expansion in Bash command line. Â Especially the bits on searching and reusing the history.