Entries by Raymond P. Burkholder

• MySensors Hardware
• OpenHardware.io
• ESP8266 Wiki - sleeping the ESP8266
• Arduino - 3.5A DC DC Buck converter, USR-ES1 W5500 SPI / Ethernet
• ESP32-POE
• freetroinics Power over Ethernet for Arduino

From my experience it's actively monitored by an individual named Devlin Null. His friends call him Dev.

Dev's backup is Helen Waite. If you expect them to take action, you can go to Helen Waite.

I'm looking for a do-all home system, something to store camera video, maybe act as media center, and host some files. This maybe over-kill, but this is what I came up with so far

I did some searching through Reddit's Small Form Factor PC, I picked up a few ideas. Most pointed idea was the link for PCPartPicker to look for Mini-ITX boards with ECC memory. I first looked at the Asus P11C-I, but it didn't have any HDMI or Display Ports, which force the use of a Graphics card. But I did like their CPU Listing site for selecting CPUs.

There was the ASRock Rack Motherboard C236 WSI, but it doesn't appear to have a location for an M.2 storage card.

But the selector didn't show what I was looking for. In a reddit post I came across GigaByte C246N-WU2 which suits my needs better.

• GIGABYTE C246N-WU2 LGA 1151 (300 Series) Intel C246 SATA 6Gb/s Mini ITX Intel Motherboard
• Intel Xeon E-2176G Coffee Lake 3.70 GHz LGA-1151 80W CM8068403380018 Server Processor Intel UHD Graphics P630 - maybe overkill, and 80W, more than the recommended 65W for the case
• Crucial 16GB DDR4 SDRAM ECC Unbuffered DDR4 2666 (PC4 21300) Server Memory CT16G4WFD8266
• Fractal Design Node 202 case. Some discussion on fans - may need a custom 3D duct for short CPU fan. 202 designs. more fan stuff
• Noctua NH-L9i fan (but may need a printed 3D duct)
• Western Digital WD BLACK SN750 NVMe M.2 2280 1TB PCI-Express 3.0 x4 64-layer 3D NAND Internal Solid State Drive (SSD)
• CORSAIR SF Series SF450 450W 80 PLUS GOLD Active PFC SFX SFX12V Micro ATX Full Modular Power Supply
• Total: CDN $2000

As a reference, there is also SFF.Network for small form factor systems.

Chassis
• Premium Builds has some MiniITX case suggestions.
• Supermicro Superchassis CSE-721TQ-250B Mini-Tower with 250W Power Supply - seems to have good airflow
• SilverStone but their airflow doesn't look good

• BPF Portability and CO-RE - Compile Once - Run Everywhere
• eBPF - Security, Tracing & Profiling, Networking, Observability & Monitoring

From 2020/08/22 bpf@vger.kernel.org mailing list

What Yonghong suggested is to deprecate bpf_load.c completely, including a legacy way to attach kprobe, which will stay connected without proper clean up, if the application crashes. This has been a reason for multiple production problems so far and we've moved away from that, as a community.

There is no need to import anything from BCC, libbpf already supports this and much more. samples/bpf unfortunately are a bit outdated (and any help to bring them more in line with modern libbpf usage would be greatly appreciated!), the best place to look at better and more modern examples would be tools/testing/selftests/bpf in Linux repo, or for more realistic examples of building tracing tools, please check [0].

[0] https://github.com/iovisor/bcc/tree/master/libbpf-tools

• Chapter 4. Common kernel-related tasks - Debian Handbook

• BitZuma - blog and link to bitcoin book

• The Ultimate List of SANS Cheat Sheets - General IT Security, Digital Forensics and Incident Response, Penetration Testing, All Around Defender Primers (Linux, PowerShell, Network)
• Blueprint: MEF-SDN/NFV Certification Exam - more for the references to SDN sources
• spam resource
• MS SNDS
• infrapedia
• Canadian Numbering
• NANPA
• small mailserver bcp
• mta-sts
• data247 - paid service

Some SSH advanced features:

• SSH Emergency Access - design a break glass procedure for reaching SSH hosts in an emergency, using security keys that you can store offline
• How to SSH Properly - a few different ways to easily improve the security of the SSH model without needing to deploy a new application or make any huge changes to user experience - certificates, bastion hosts, 2-factor authentication
• SSH Handshake Explained
• gravitational / teleport - from How Uber, Facebook, and Netflix Do SSH

Is Parallel Programming Hard, And, If So, What Can You Do About It? - The purpose of this book is to help you program shared-memory parallel machines without risking your sanity.

It provides in-depth analysis of parallel programming at the cpu level of programming. A downloadable, git versioned, pdf.

Seen on the IQFeed Developer Support 2020/04/21. A solution for allowing ICMP packets.

iqconnect.exe does a ping round trip against its DTN servers (you can see the ping results at IQConnect.log when you stop the feed and iqconnect.exe exits). Thing is, ping uses ICMP protocol, which in linux is somewhat privileged.

So, you need to give wine the appropiate permissions in order to be able to use ICMP. Running wine as root in order to circumvent this problem would be overkill (besides a very bad thing to do!), but fortunately you can use setcap in order to grant permissions in a much more granular way.

First, locate where your wine-preloader file is. In my case, it's on /usr/bin/wine-preloader . Then, type (yoo will need to sudo for this):

sudo setcap cap_net_raw+epi /usr/bin/wine-preloader

and that's all. Now wine is allowed to use ICMP protocol, which in turn will allow IQconnect.eze to make its "ping things" without complaining

In a follow on post to my previous GUI From an LXC Container on the Host entry, here are some notes on linking sound in an LXC container to the host's sound system.

The primary reason for this was to get around Interactive Broker's broken sound requirements for really old libav libraries. Which is back to the version x53 libraries from the Debian Jessie / Ubuntu Precise 12.04 days. Long story short, I don't have this working yet. The basic issue I have is that, when running TWS in an LXC container, all the configuration menu options but one work. When I click on the 'Sound Manager' menu item, TWS locks up, and I don't see any log messages anywhere as to why this might happen. So there is something special in an LXC container environment which is locking up sound in TWS.

But I did get sound from FireFox / Youtube to work.

This on a Debian Bullseye system.

The basic solution is, in the LXC container configuration file, to mount the Pulse Audio socket from the user's account of the host into the container and set an environment for the user in the container. In this case, the user has UID of 1000:

lxc.mount.entry = /run/user/1000/pulse/native tmp/pulse/native none rw,bind,create=file 0 0
lxc.environment = PULSE_SERVER=unix:/tmp/pulse/native

For completeness, these can be added (helps with ALSA):

lxc.mount.entry = /dev/snd dev/snd none bind,optional,create=dir
lxc.cgroup.devices.allow = c 116:* rwm

That is about all to make it all work. Some or all of the following package installs in the container might help:

sudo apt install \
  pulseaudio \
  pulseaudio-utils \
  pavucontrol \
  gstreamer1.0-libav gstreamer1.0-plugins-bad gstreamer1.0-pulseaudio \
  mpg123

I am almost embarrassed to say that I missed a good night's sleep sifting through erroneous out of date misinformation, missing some subtle distinctions, and winnowing out the chafe.

This all started when I wanted to give Krita a try for editing photographs. It is said it is the next best thing in open source when compared to PhotoShop. When installed on my Debian Linux workstation, all I could get out of it was crashes of one form or another. I'm not really surprised as my workstation has been through various combinations of buster, testing, bullseye, sid and experimental. Some package is out of sync somewhere.

So.. since I know how to run LXC containers, I figured I'd give that a try. That was successful, to a point. I used X2Go for remote console. But when my images are Nikon NEF files at 24Megapixels at 14bits each, file size, computation, and visualization are a bit of challenge (the screen updates being the main challenge). A wide erasure brush was slow, even on my speedy machine.

There are sites which vehemently say that there is no direct way to see the GUI from a container on a workstation host. Sigh. Misinformation. Then there are the five year old sites which show how it is done, but have extra commands, missing commands, or missing options. More sigh.

After much trial and error and trying the same things over again, with minor variations on the theme, in the hopes something might fix itself, it was a long night.

For the record, here is my research on a Debian Bullseye system with LXC '1:3.1.0+really3.0.4-3' Continue reading "GUI From an LXC Container on the Host" »

Some C++ libraries I've encountered for managing currency manipulation:

• vpiotr / decimal_for_cpp - this is the one I use for my currency work, is header based, succinct, and easy to use.
• I was wondering if boost.multiprecision could be used, and came up with mariusbancila / moneycpp - a bit too much for me as it also handles currency codes. There is a a blog entry: moneycpp – a C++ library for handling monetary values.
• General Decimal Arithmetic goes into some detail about the related IEEE 754 standard, as well as a link to a C language implementation.

From Debian Misc Developer News (#51):

Steve McIntyre created[3] a debian-preseed[4] service that extracts all of the debconf templates in the Debian archive and lists each of the possible preseed options available along with their descriptions. If you want to repeat the extractions, you can use Steve's new Perl script or the existing tools on the preseed wiki page[5].

-- Paul Wise

• [3] https://blog.einval.com/2020/02/24#what_can_you_preseed
• [4] https://jack.einval.com/debian-preseed/
• [5] https://wiki.debian.org/DebianInstaller/Preseed