calvin2021y

How to use a TPM on Linux

Prerequisites

I use it on Arch Linux
Install dependency: yay tpm2-tools

Do I have a TPM 2.0?

kmille@linbox:~ journalctl --boot --dmesg --grep=tpm_tis

Podman with docker-compose on MacOS.

Podman an alternative to Docker Desktop on MacOS

Getting podman installed and started is super easy.
Just use brew to install it.

> brew install podman

Now since podman uses a VM just like the Docker Client on MacOS we need to initialize that and start it.

Install `dnsmasq` and configure for *.dev.local domains

$ brew install dnsmasq
$ vim /usr/local/etc/dnsmasq.conf

Reload configuration and clear cache

# Copy the daemon configuration file into place.
$ sudo cp $(brew list dnsmasq | grep /homebrew.mxcl.dnsmasq.plist$) /Library/LaunchDaemons/

$ sudo launchctl unload /Library/LaunchDaemons/homebrew.mxcl.dnsmasq.plist

Note: these instructions are for pre-Sierra MacOS. Sierra (10.12) and newer users see https://gist.github.com/gravitylow/fb595186ce6068537a6e9da6d8b5b96d by @gravitylow

If you are getting this in gdb on OSX while trying to run a program:

Sample config for 2 million web socket connection

    sysctl -w fs.file-max=12000500
    sysctl -w fs.nr_open=20000500
    # Set the maximum number of open file descriptors
    ulimit -n 20000000

    # Set the memory size for TCP with minimum, default and maximum thresholds 
 sysctl -w net.ipv4.tcp_mem='10000000 10000000 10000000'

FFmpeg Minimal Build for RTMP Streaming

This tutorial will work you through steps of configuring an FFmpeg build tailored for RTMP streaming on macOS. At first I think of making it support general live streaming, with additional protocols like HLS, but to keep things simple let's stick with RTMP for now. (Anyway, I do include HLS in the protocol list as well as some related bitstream filters but it's untested.)

Goal

The built FFmpeg executable should

	# npm using https for git
	git config --global url."https://github.com/".insteadOf [email protected]:
	git config --global url."https://".insteadOf git://

	# npm using git for https
	git config --global url."[email protected]:".insteadOf https://github.com/
	git config --global url."git://".insteadOf https://

	#
	# CORS header support
	#
	# One way to use this is by placing it into a file called "cors_support"
	# under your Nginx configuration directory and placing the following
	# statement inside your location block(s):
	#
	# include cors_support;
	#
	# As of Nginx 1.7.5, add_header supports an "always" parameter which

	// 1) "Tables of linear congruential generators of different sizes and good lattice structure" (1999), Pierre L'Ecuyer
	// 2) Pre-print version of (3) (https://arxiv.org/abs/2001.05304)
	// 3) "Computationally easy, spectrally good multipliers for congruential pseudorandom number generators" (2021), Guy L. Steele Jr. & Sebastiano Vigna (https://onlinelibrary.wiley.com/doi/epdf/10.1002/spe.3030)

	// inline comment number is bit width of constant

	const uint32_t lcg_mul_k_table_32[] =
	{
	// (3) Table 4 LCGs
	0x0000d9f5, // 16