Author Archives: Scott Alfter

Fun with the new server

Over the past couple of months, I’ve been migrating this site (and others) off of an older virtual server that ran Gentoo Linux onto a newer one running Alpine Linux and Docker. I have a pile of scripts that set up and maintain each service on the new server, and Ouroboros keeps most things up to date faster than an emerge -uNDv world && emerge --depclean ever did. For the services that Ouroboros doesn’t keep up to date (because they’re containers I generated myself), there’s a script that regenerates them with whatever upstream sources are current. So far, I’ve only been stung once when an upgrade of MariaDB to 11.3 broke most of my websites, but rolling it back to 11.2 set things right again.

There are also some things that got revisited in the move that needed to be brought up to date. For instance, there used to be a mailing list called the Homebrew Digest. It’s been gone for some time now, but it had nearly 100k posts to it going back as far as the late ’80s covering all aspects of homebrewing. Someone else had an archive up, but it’s also succumbed to bit rot. 15 or so years ago, I put up my own searchable archive, but it had suffered from neglect and the resulting breakage from moving to newer versions of PHP. I’ve recently dusted it off, tweaked it where needed, and put it up again at hbd.beerandloafing.org. It was previously integrated into another website I’d not changed much since 2004, but has been broken out into its own site running in its own container.

That other site, www.beerandloafing.org, is now home to a BrewBlogger instance. That’s another piece of web code that hasn’t been maintained much…it still needs PHP 5 to run. Putting it in its own container made it easy to cater to its needs while the other PHP-based sites I have (including the HBD archive) can run on more up-to-date versions. (If you’re interested in running BrewBlogger on Docker, you can pull it from Docker Hub or grab the Dockerfile from my GitLab.) Once I got it running, I imported the database from the old server into it. Most of my recipes are still in ProMash, an even older piece of software and the main reason I have WINE running on my computers. (ProMash was written for Windows, but my computers spend 99%+ of their time running some form of Linux.) As I get around to it, I’ll transcribe the recipes and brew sessions from ProMash into BrewBlogger.

Cheatsheet: Raspberry Pi + Alpine Linux + OctoPrint

The last upgrade to Raspbian Raspberry Pi OS broke the WiFi connection to my 3D printer in an inconvenient way, as it runs headless with just a 4-pin power-and-UART connection. I’ve been having pretty good luck lately with Alpine Linux on various systems (including a Docker host and a cluster of Raspberry Pi 4s I knocked together to try to wrap my head around Kubernetes), so I thought I’d put it on the Compute Module 4 that drives my printer. I backed up the OctoPrint config that was on it and got a replacement configuration running on a spare Raspberry Pi 3 at first. Here’s what I came up with in the way of what needs to be done to put Alpine Linux on a Raspberry Pi and bring up OctoPrint on the resulting system.

  • Download the Alpine Linux tarball that’s appropriate for your Raspberry Pi from here. (For the RPi 3 and up, you most likely want the aarch64 image. This is especially true for the RPi 4 and up with 4 GB or more of RAM.) Instructions on how to do this are available elsewhere, but the short version is that you want to unpack the tarball to a FAT-formatted MicroSD card (or USB stick if you’re targeting a Compute Module 4 with onboard eMMC), boot from the device, and run setup-alpine to install. Toward the end, you want to install it in “sys” mode. Reboot to bring up the new system, and then log in. You would’ve needed a monitor and keyboard to set up Alpine, but if you’ve set it up right, you can ssh into it from here on out.
  • Edit /etc/apk/repositories to enable the community repository. (This is needed for vcgencmd.)
  • Install needed software:
    doas apk add gcc make musl-dev linux-headers libffi-dev nginx raspberrypi-utils-vcgencmd python3-dev
  • Install OctoPrint:
    python -m venv --upgrade-deps octoprint
    octoprint/bin/pip install https://gitlab.alfter.us/salfter/marlin-binary-protocol/-/archive/v0.0.8/marlin-binary-protocol-v0.0.8.tar.gz
    octoprint/bin/pip install octoprint

    (The marlin-binary-protocol installation is needed if you want to use the Firmware Updater plugin and need to use its marlinbft driver. My printer uses a BTT SKR 1.4 Turbo, an LPC1769-based board that can use this driver for firmware uploads.)
  • Edit /etc/fstab to disable tmpfs on /tmp. (Restoring backups from another OctoPrint instance will probably fail if you don’t.)
  • Copy the following to /etc/nginx/nginx.conf:
    worker_processes 1;

    events {
    worker_connections 1024;
    }

    http {
    include mime.types;
    default_type application/octet-stream;
    sendfile on;
    keepalive_timeout 65;

    map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
    }

    upstream "octoprint" {
    server 127.0.0.1:5000;
    }

    upstream "mjpg-streamer" {
    server 127.0.0.1:8080;
    }

    server {
    listen 80;
    server_name localhost;

    location / {
    proxy_pass http://octoprint/;
    proxy_set_header Host $http_host;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Scheme $scheme;
    proxy_http_version 1.1;

    client_max_body_size 0;
    }

    location /webcam/ {
    proxy_pass http://mjpg-streamer/;
    }

    # redirect server error pages to the static page /50x.html
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
    root html;
    }
    }
    }
  • Create /etc/local.d/octoprint.start with the following and make it executable:
    #!/usr/bin/env ash
    su - salfter -c "nohup /home/salfter/octoprint/bin/octoprint serve 2>&1 >/dev/null &"

    (change “salfter” to whatever user you’re using)
  • Create /etc/local.d/octoprint.stop with the following and make it executable:
    #!/usr/bin/env ash
    pkill octoprint
  • Check /etc/inittab to make sure the serial console isn’t enabled.
  • Add the following to /boot/usercfg.txt:
    enable_uart=1
    gpu_mem=16
    dtoverlay=pi3-disable-bt

    [cm4]
    otg_mode=1

    Reboot so the changes take effect.
  • Enable the nginx and local startup scripts:
    doas rc-update add nginx
    doas rc-update add local
  • Add the user under which OctoPrint runs (in my case, that would be salfter) to whatever group /dev/ttyAMA0 belongs (root, in my case).
  • Edit /etc/doas.d/doas.conf to allow doas to work without a password (needed so OctoPrint can restart itself):
    permit nopass :wheel
  • Reboot and wait for OctoPrint to come up on port 80. Restore your backup (if you have one) and you’re done!

Cheatsheet: convert WRL to STEP with open-source tools

I had some electronic component models (obtained via easyeda2kicad) that I needed to convert to STEP so they’d show up when I brought a board using these models into FreeCAD with KicadStepUp. I tried doing the job in FreeCAD alone, but while WRL files are basically meshes (not too different in theory from STL files), FreeCAD’s mesh-to-shape conversion wanted nothing to do with them. I searched for

I ended up using Wings3D to convert from WRL to STL, and then used FreeCAD to convert from STL to STEP:

  1. Import the WRL file into Wings3D. Check the “swap X & Y axes” box and set the import scale to 2.54. Export to STL.
  2. Import the STL file you just created into FreeCAD.
  3. (optional) Switch to the mesh workbench and decimate the mesh (Meshes -> Decimation…).
  4. Switch to the part workbench, create a shape from the mesh (Part -> Create shape from mesh…, then make sure “sew shape” is checked), and convert the shape to a solid (Part -> Convert to solid).
  5. Export the solid to STEP.

These models definitely won’t look as nice as models created from a proper CAD workflow (you can even import from OpenSCAD, export that to STEP, and get something pretty decent), but if you just need a model of your PCB for mechanical integration, it’ll get the job done.

Cheatsheet: install debloated Windows 11 on QEMU

This pulls together tips from https://christitus.com/windows-11-perfect-install/, https://christitus.com/install-windows-the-arch-linux-way/, https://blogs.oracle.com/virtualization/post/install-microsoft-windows-11-on-virtualbox, and some other sources I’ve forgotten. It’s mainly aimed at getting Win11 running under QEMU on Gentoo Linux, but should also work for bare-metal installs, QEMU on other platforms, or other virtualization platforms (VMware, VirtualBox, etc.).

  1. Verify kernel prerequisites as described in https://wiki.gentoo.org/wiki/QEMU
  2. Install app-emulation/qemu and app-emulation/libvirt
  3. Start /etc/init.d/libvirtd, and add it to the default runlevel:
    sudo rc-update add libvirtd
  4. Add yourself to the kvm group:
    sudo usermod -aG kvm `whoami`
  5. Download the latest Win11 ISO from https://www.microsoft.com/software-download/windows11
  6. Download the latest libvirt driver ISO from https://github.com/virtio-win/virtio-win-pkg-scripts/
  7. Start virt-manager and create a new VM, installing from the Win11 ISO. Most defaults are OK, with the following exceptions:
    a. Change virtual disk storage bus from SATA to virtio
    b. Add new storage, select the driver ISO, and change type from disk to CD-ROM
    c. Change network device type from e100e to virtio
  8. Start the VM; Win11 setup should begin.
  9. Disable TPM and Secure Boot checks in the installer:
    a. When the installer begins, press Shift-F10 and launch regedit from the command prompt.
    b. Add a new key named LabConfig under HKLM\SYSTEM\Setup
    c. Add two new DWORDS to HKLM\SYSTEM\Setup\LabConfig named BypassTPMCheck and BypassSecureBootCheck, and set both to 1.
    d. Exit Regedit, close the command prompt, and continue.
  10. Optional: when prompted during installation, select “English (World)” as the time and currency format. This causes a bunch of bloatware and other crap to not be installed.
  11. After installation on the first boot, press Shift-F10 again and enter this to cut OOBE short:
    oobe\BypassNRO
    This will trigger a reboot, followed by a less intrusive offline OOBE process (necessary because the virtual NIC isn’t working yet, and it’s a good idea anyway).
  12. Once the system’s up and running, run virtio-win-guest-tools.exe from the driver ISO to install the remaining needed drivers and other tools.
  13. If you selected “English (World)” as the time and currency format when installing, start intl.cpl and make sure all settings are as they should be (whether “English (United States)” or whatever’s appropriate for you). Do the same for “region settings” in the Settings app.
  14. Open Microsoft Store, search for “App Installer,” and update it…need to do this for Winget to work. (TODO: is there a way to do this with a normal download instead?)
  15. Open a PowerShell admin window and launch Chris Titus’s tweak utility:
    irm christitus.com/win | iex
    Use it to debloat your system, install the software you want, etc.
    Warning: Removing the Edge browser with this utility may break other apps (I know for certain that Teams won’t work), and it might not be possible to get it working right again without a full reinstall. It appears that Edge is embeddable within applications in much the same way that Internet Explorer was once embeddable. Plus ça change
  16. Check for Windows updates in the usual manner.

More Win11-without-TPM/Secure Boot tricks

https://nerdschalk.com/install-windows-11-without-tpm/ has several methods that might be useful, especially for upgrading from Win10 or earlier (as opposed to the clean install described above).

For upgrading to Win11 22H2 from an earlier version, https://jensd.be/1860/windows/upgrade-to-windows-11-22h2-on-unsupported-hardware should be useful.

Two-Tier Justice

We are no longer a nation of laws:

Wesley Snipes – 3 years in prison for tax evasion.

Mike Sorrentino, Jersey Shore – 8 months in prison for tax evasion.

Ja Rule – 28 months in prison for tax evasion.

Darryl Strawberry – 3 months in prison, 3 months of house arrest for tax evasion.

Fat Joe – 4 months in prison for tax evasion.

Joe and Teresa Guidice – 4 years and 1 year in federal prison for tax evasion.

Heidi Fleiss – 37 months in prison for tax evasion.

Chuck Berry – 3 months in prison for tax evasion.

Richard Hatch – 51 months in prison for tax evasion.

Leona Helmsley – 4 years in prison for tax evasion.

Hunter Biden – No JAIL TIME

So no liberals, tax evasion crimes absolutely result jail time. Unless you are the crackhead son of the most corrupt administration in the history of this country.

https://twitter.com/DefiyantlyFree/status/1671247236678963200

On “insurrection”

Perhaps this would’ve been more timely closer to 6 January 2021, but it’s no less timely now that we have proof the government has been lying about the origins of the recent “pandemic” (among other things). The next time you hear some idiot in Congress, the White House, or wherever bleating about “insurrection,” keep this quote in mind:

We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.–That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, –That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.

— Declaration of Independence

For how much longer will you consent to the current form of “governance?”

CH32V links and cheatsheet

A while back, I found this Hackaday article that led me down a rabbit hole of cheap RISC-V microcontrollers. This post will mainly be a link dump and random notes on making use of these devices.

An ffmpeg cheatsheet

I recently had some need to clean up the subtitles in some video files in my possession. It took a little while to track down the exact set of options to get it to do what I wanted it to do, so I’ve written them down here for future reference. This post may be amended from time to time to add more

Extract subpictures from file

The second number in the -map parameter selects the (zero-indexed) stream to extract. Use something like mediainfo to determine which stream to select, then issue something like this:

ffmpeg -i src.m4v -c copy -map 0:2 dest.en.sup

Subtitle Edit can read subpictures and convert them to text subtitles. As long as you have a .NET runtime available, it should work; I’ve run it on Windows 11 and Gentoo Linux. Its accuracy is pretty good, especially if you have it use one of the Tesseract OCR engines.

Extract text subtitles from file

ffmpeg -i src.m4v -f srt dest.en.srt

“srt” can be replaced with several other formats (ssa, ass, etc.) if you want those. Depending on the source, there may be extra HTML formatting that you might want to use sed to filter out. If more than one subtitle stream is present, a “-map” parameter may be necessary to select the one you want.

Mux text subtitles into file

ffmpeg -i src.m4v -i src.en.srt -c copy -c:s mov_text -map 0:0 -map 0:1 -map 1:0 -metadata:s:2 language=eng -metadata title= dest.m4v

Assumptions: the desired video and audio are in the first two streams of the first file, and the subtitles are in English. (Audio language should already be set in that stream to whatever it is.)

“-metadata title=” will clear out the title string that might have been set in the original file.

Selecting tracks by language

Instead of needing to look up track numbers, it’d be nice to just specify the language(s) we want to include. That is possible, with something like this:

ffmpeg -i src.mkv -c copy -map 0:v:0 -map 0:a:m:language:ger -map 0:s:m:language:eng dest.mkv

This example selects German audio and English subtitles…useful for something like Das Boot or Deutschland 83. (Assuming that you like foreign shows in their original language with English subtitles, anyway…which I do.) These track mapping options should also apply in the preceding examples.

Extracting chapters from existing file

ffmpeg -i src.mkv -f ffmetadata src.metadata

This creates a file with chapter information (and possibly other metadata) structured like this:

;FFMETADATA1
encoder=Lavf60.3.100
[CHAPTER]
TIMEBASE=1/1000
START=0
END=728102
title=Chapter 1
[CHAPTER]
TIMEBASE=1/1000
START=728102
END=1319902
title=Chapter 2
[CHAPTER]
TIMEBASE=1/1000
START=1319902
END=2008965
...

Inserting chapters

A metadata file structured as above can be inserted into a file when it’s encoded:

ffmpeg -i src.mkv -i src.metadata -map_chapters 1 ...