6 aug

I talked with Scott over the weekend about npm packages and dependencies. I’m going to try taking the ^ character out of the package.json file for packages I want to use old stuff with. I learned that the ^ means npm will install newer versions of the package if there aren’t breaking changes (major update). That’s not what I want.

• removed carat from package.json
• ran npm install and everything is fine?
• uninstalled johnny-five and serialport and installed v 0.12.0 of johnny-fve
• same errors: serialport @6.0.5 no prebuilt binaries for node 8.11.3, arch=arm, platform=linux
• big duh moment: support for raspi linux with arch=arm doesn’t exist
• how does johnny-five have serialport as a dependency if it doesn’t work on linux ARM platforms?!
• did some more digging through issues, someone suggested having gcc but that didn’t work
• gcc itself suggested installing google-closure-compiler-js since they no longer update gcc (four years!)
• uninstalled/reinstalled johnny-five 0.12.0, but still getting the prebuilt binaries error
• read more node-serialport and raspi-io issues, all their fixes were things I already have installed, so I’m at impasse again.
• thought maybe I got really lucky when I came across getting a raspberry pi ready for nodebots, but I’ve done all this stuff.
• noticed I didn’t have node-gyp installed (how?), so installed that; went through j5 uninstall-reinstall, still nothing
• saw a comment in an issue about cloning the node-serialport github repo and installing it locally; took forever but it installed successfully without the same errors I’ve been getting
• had a thought: could my old npm version be the issue? upgraded npm version in just one directory to test; no avail

I’m going to walk away from the serialport stuff for a while. I was hoping that if I could get a clean npm install that it would clear up whatever access issue I’m experiencing inside the Docker container, but I’m still not sure that serialport and modprobe are connected in any way. I get a weird error during npm install of serialport, but still somehow end up with serialport installed, so I’m not sure that’s the error that’s holding this up.

Going back to building docker images:

• still working with the new raspbian-stretch image
• it must be pretty bare bones… no node/npm installed, so I’m working on that
• sudo not installed??
• installed sudo but now it’s getting stuck on pigpio surprise

I don’t have time to run this whole thing again today, so tomorrow I need to:

• preinstall pigpio
• take a look at Alpine Linux for serialport

7 aug

Starting the day off strong with a new directory for exploring a docker container with Alpine Linux/node.

• repo: mhart/alpine-node
• copied Dockerfile, .dockerignore, gate-counter.js, and package.json
• updated files to match new image
• attempted to build image
• got a weird error

After googling, I found that resin has an alpine-node base image specifically for rpi3.

• docker hub: resin/raspberrypi3-alpine-node
• made new directory
• copied Dockerfile, .dockerignore, gate-counter.js, and package.json
• updated files to match new image

Alpine is very diferrent than Raspbian. Package manager is apk instead of apt-get. I’m struggling to get normal packages installed. When I try to get npm to install my packages, it says it can’t find pigpio. That’s because it’s not installed. But I can’t figure out how to install pigpio without apt-get! I tried downloading wget, unzip, and make so I could download the package, unzip it, and install it using make, but now I’m getting an error from make, and I DON’T UNDERSTAND ANY OF THIS.

Gotta take a break until tomorrow.

8 aug

I was pretty fed up yesterday. Let’s hope some tunes and extra coffee can help me figure this out today.

Current situation:

• Depending on the docker build, I’m having issues with either
  • pigpio which needs to be installed on the system as well as in the node modules
  • raspi-io my/Johnny Five’s chosen library for gpio pins on the raspi, which has to be installed as non-root user but then must be run as root
  • serialport because of a pre-built binaries problem
• Docker images/OSes
  • Raspbian was an easy choice, since it’s what I built my app with
    • For whatever reason, all the raspbian builds I’ve done have failed because of the above libraries
    • Several serialport issues suggested using an alpine node build, so I switched, but that’s causing a whole new set of problems

Since I can’t debug alpine issues from my raspi, I built a blank resin/raspberrypi3-alpine-node container (no app) so I can work on installing pigpio from inside

• used the Dockerfile from the docker hub page
• ran the conatiener using --cap-add=ALL --privileged because it was struggling to build the resin files
• gave me some error about not having a CMD command (I don’t)
• so I exited the container, then used docker exec <container ID> /bin/bash to start messing around in alpine
• made sure all the things were installed (build-base, sudo, python)
• added the things serialport suggests (linux-headers, udev)
• git cloned gate-counter from repo
• attempted to npm install the stuff from README
• hung up on raspi-io because pigpio isn’t installed; can’t auto install because apt-get isn’t a thing in alpine
• pigpio install is failing at same point as during Docker build: final step sudo make install at ldconfig step
  • after much googling, I think this might be because ldconfig is a glibc thing and alpine is musl standard library
  • confirmed: thanks to this listserv
  • I believe this means alpine linux is out
  • going to step away from the alpine stuff for now

Going back to the original new-test directory and seeing if any of my new-found knowledge will help debug this nonsense - added pigpio stuff to Dockerfile’s RUN apt-get install line and double checked my node_modules - still getting all that crazy error stuff when installing serialport but I don’t think it matters - spun up a container and got a modprobe i2c error - so I guess I’m back to “do I even need i2c stuff since I’m not using i2c pins?”

Got into new-test container using exec so I could dig around in the files

• This is the full error message from the npm install stage:

    Error: Command failed: modprobe i2c-dev
    modprobe: ERROR: ../libkmod/libkmod.c:557 kmod_search_moddep() could not open moddep file '/lib/modules/4.14.34-v7+/modules.dep.bin'
  

• Went looking for the /lib/modules folder, but it doesn’t seem to exist (!!)
• Some stack overflowing suggested I install linux-headers (d’oh! that was suggeted in the serialport docs, too)
• Ran

  sudo apt-get install linux-headers-`uname -r`
  

• …and got a new error:

    E: Unable to locate package linux-headers-4.14.34-v7
    E: Couldn't find any package by regex 'linux-headers-4.14.34-v7'
  

• After more googling about resin images w/o /lib/modules folder, found an issue about mounting the volume at docker run (which again, is something that has been suggested before)
• This ran the gate-counter.js app w/o error, but also closed the board and exited the app:
  • docker run -it --cap-add=ALL --privileged -v /lib/modules:/lib/modules carylwyatt/new-test
• Now… how to keep it running?
• ran in exec mode
• ran sudo node gate-counter.js
• IT’S WORKING!!
• 

Just a personal note to self: yesterday, you were so frustrated by this you almost cried ~10 separate times. Even last night when you were telling Scott all about it, you almost cried again. You’re not a crier. You were legit angry at this not working after a full MONTH and you still couldn’t figure it out. After sleeping on it, you came back with a clear head and kept going. YOU DID IT.

Okay, it’s running, but the ajax request isn’t being sent correctly. I’ll get this sorted out after a massive celebration. I’m guessing this is a problem with the exposed port. That whole part of the docker container has not been on my radar as of yet.

9 aug

HTTP request problem solved: when I cloned my github repo I forgot to change the fake google URL to the real google URL.

I did end up changing my Dockerfile to expose port 443: EXPOSE 443 and added the -p 443:443 to the docker run command. I have no idea if this made any kind of difference, so I might end up testing and modifying that later.

Now I just need to figure out how to run the docker container indefinitely. I assume it has something to do with the detacehed flag -d. I’m also not sure it matters whether or not the app runs on the docker run command. It currently initializes the REPL and immediately closes the board… I wonder why?

imaging

Now that I’ve (mostly) figured out the Docker piece of this puzzle, it’s time to move on to imaging an SD card with my version of raspbian that includes Docker and my app container, is secure via ssh, and auto-upgrades raspbian.

In order to get a fresh raspi image to copy, I’ll have to set up a clean SD card. I’m thinking these will be my steps:

• flash blank SD card with latest (or currently running??) raspbian
• run through 5 best basic security tips to create secure pi (create new user, remove pi user, set new password, add Fail2Ban, install unattended-upgrades, set up ssh key pairing)
• install docker
• build docker image/container

I assume that will take me most of tomorrow (after the academic affairs kickoff). After how much trouble I had flashing the SD card previously, I’m hoping this time it won’t be so hard. I’m probably wrong, but hopefully I’m older and wiser now, right?

Then I can attempt to save the disk as an image and flash another one. Yay!

Links for tomorrow:

• How to set up SSH keys on raspberry pi
• How to prepare raspberry pi SD card on chromebook
• Self-updating IoT apps on the raspberry pi using docker
• hypriot’s flash repo
• create a custom raspbian os image for production
• getting started with docker on your raspberry pi
• PiBakery

10 aug

I just realized that the gate-counter time is ahead of eastern by 4 hours. I have no idea why, but I will figure it out later. Today is all about imaging.

Flashing blank SD card with raspbian:

• two ways I could go: chromebook or raspi itself
  • first option chromebook
  • sadly, it can’t hold much and is pretty full as it is, so I’m downloading raspbian (1.6GB) onto a flash drive and hoping for the best
  • downloaded zip file to flash drive, then extracted the image (25MB) and saved to downloads folder
  • now following directions from how to prepare raspberry pi SD card on chromebook
  • the flashing seems to have worked; writing from the chromebook to the card took ~5 minutes
  • the flash worked… in a way. The pi knew it was raspbian, etc. but there was some kind of kernel panic error message that I googled. I ended up running the flashing process again, but it did the same thing.
• now I’m going to try to find a linux tool for writing to an SD card instead of dd in the terminal
• tried to install CLI version of etcher; it installed just fine, but then gave me an error about not being able to find command etcher.js
• downloaded the linux-x64 GUI etcher app since it’s what I used on the macbook to flash the original SD card
• installed just fine, but then gave me a crazy error No polkit authenticatin agent found
• did all the googling/github issue finding/stack overflowing
  • tried installing other policy kits
    • most of the ones I tried to install “didn’t exist” in apt-get
    • could not find the ones recommended in the arch/xfce wiki
  • tried reading the man pages for polkit to learn about config/autostart
• I probably fell too deeply down that particular rabbit hole, because before I knew it, it was well after lunch time
• I’m going to take the SD card home for the weekend and try to find time to use etcher to flash a clean image of raspbian and run it on scott’s pi zero

wrap up

All in all, a frustrating but very successful week. I got a lot accomplished thanks to the semester break schedule and several library staff members being out. It’s hard to find uninterrupted time to deep dive on these problems, so it’s nice to have a few hours carved out during break weeks– even between lots of unnecessary meetings.