Sun ILOM Cheatsheet (BASH)
Most Sun/Oracle servers have an integrated BMC known as Integrated Lights Out Management (ILOM) or occasionally Advanced Lights Out Management (ALOM)
This page provides a cheat-sheet of commands you might commonly use having connected to the ILOM via SSH
racadm cheatsheet for Dell iDRAC (BASH)
The Integrated Dell Remote Access Controller (iDRAC) is an optional BMC used in Dell servers. Much like with HP's ILOM there is a command line utility provided (in this case racadm) in order to interact with it, fetching and setting config
This page is a basic cheatsheet of the commands which can be used with it, all should be run from a shell. However, if you prefer to use the interactive mode, run racadm on it's own, and then just omit racadm from the command. The benefit of that approach, is that from (approximately) racadm7 you'll have tab-completion available to help you create commands
HPACUCLI Cheat Sheet (BASH)
hpacucli is a utility provided by Hewlett Packard (HP) to interact with their Smart Array controllers. The commands below were used on a RPM based distribution, but should work across all Linux flavours
You can run them by either entering interactive mode (i.e. just run hpacucli and then enter the commands), or directly from the shell (by prefixing them with hpacucli
Imploding a table (LUA)
LUA's concat method works just like PHP's implode, so simply needs to be called in a similar manner.
Returns a string containing each of the table entries, delimited by whatever delimiter is passed into concat
Get Video Keyframe Interval (ffprobe) (BASH)
The command will output where keyframes exist within the input video. Useful to know when trying to segment for HLS etc, or troubleshoot playback issues
Getting connection speed metrics from curl (BASH)
The command gets curl to request a page and then write out a CSV delimited line giving details of the time it took to complete various stages of the request, including how many redirects were followed etc.
Ultra-Low latency RTMP playback with ffplay (BASH)
RTMP video provides a means for video playback with ultra-low latency. However, most players will maintain a (small) buffer, so you may still see latency of a few seconds.
If you're wanting to test the latency imposed by the delivery layer, you'll probably want to factor out the players latency. With ffplay you can do so by reducing the probesize and telling the player to use the external clock for sync.
These are not production values, and in the real-world you'll likely sacrifice playback reliability, so should only be used for testing/debugging.
Publishing Webcam to RTMP (FFMPEG) (BASH)
Short command to push video from a Video4Linux compatible webcam to RTMP
Generating htpasswd entry with OpenSSL (BASH)
Generally when generating a htpasswd entry for Basic Authentication you'd use apache-utils to do it. On a server running only NGinx, this probably won't be available, so you instead need to do it with openssl