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PiBuilder + Windows: Discord question

Question 1

I tried to build a new installation using PiBuilder. I am a Windows user and connect with a terminal emulator (Putty) to the Pi. So far I was not successful. I tried to follow the description. But Windows only mounts the boot partition. The rest of the SD card is not visible to the OS. So I struggle with the step of configuring PiBuilder and also the many steps just to connect to a Pi using SSH.

Answer

macOS is the same as Windows - it can only mount the boot partition. That's why I put all the files on the boot partition. It's the easiest way of getting everything onto the Pi.

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IOTstack - Using the PiHole container as your container DNS

First, a small bit of editorialising (my gist, my rules). PiHole is an excellent ad-blocker. It's perfectly OK for just about every other device on your home network to use PiHole as its primary DNS.

The one device in your network that shouldn't use PiHole-in-a-container for its DNS is the Raspberry Pi running PiHole in a Docker container. I'll go so far as to describe it as a seriously dumb idea.

Why? Several reasons:

• Containers start quite late in the boot cycle. Any process starting before Docker that depends on the DNS being "there" can be disappointed. PiHole being late to the party and occasionally disappearing when you do perfectly ordinary things like…
• … Taking down your stack can trigger resolver failover conditions which don't always recover gracefully. You might think your DNS setup is working just fine with the PiHole container in the prime role but then it all turns to custard and you don't know why.

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IOTstack tutorial : local image reversion

One of the main advantages of running services in Docker containers is the relative ease of reverting to the last-known-good container.

One of the biggest problems with reverting to the last-known-good container arises if you don't already know the tag of the image you want to revert to. Sometimes it can be a bit tricky to figure it out. You usually need to go to the container's "tags" page on DockerHub, sort through the update history for your architecture, pick the appropriate tag, edit your compose file to specify that tag, and then, in the words of the old Knight in the third Indiana Jones movie, hope that you have "chosen wisely".

Your chances of choosing wisely are inversely proportional to the amount of panic you're feeling after you realise a key container isn't working and reverting is your best strategy. Panic is the enemy of clear thinking and reasoning.

There is, however, another way. The method described here means you retain the last-known-

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Preparing a Pull Request for IOTstack

If you want to fix a bug or propose an enhancement for IOTstack, you will need to prepare a Pull Request (PR).

Please don't try to do anything in this gist inside an ~/IOTstack folder on a Raspberry Pi that is also being used to run your Docker containers. It's easy to get confused and you could accidentally break your own working IOTstack.

You can do everything on the same Raspberry Pi that is running your IOTstack but it's usually easier to work on a desktop or laptop. If you accept this advice, there's no risk of breaking your running IOTstack.

This guide barely scratches the surface of Pull Requests. There is lots of advice on GitHub and Google will find plenty of hits for any question you might have.

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On IOTstack, InfluxDB 1.8 & INFLUXDB_DATA_INDEX_VERSION

Updated 2022-05-19

• Additional observations since reverting to in-memory indexing.

the trigger question

On March 12 2022 I noticed a post on Discord by Ukkopahis saying:

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IOTstack + Node-RED + pigpiod

Problem Statement

The following problem was reported on the IOTstack Discord channel:

Today I rebuild my IOTstack from scratch using the Pibuild process and after restoring my nodered flows I noticed that my serials and GPIO are not connecting anymore.

I don't use node-red-node-pi-gpiod myself but I have been able to reproduce the problem.

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Tutorial: MQTT and the retain flag

Assumptions and setup

This tutorial assumes:

• a single computer (like a Raspberry Pi)
• MQTT broker (like Mosquitto) running
• the mosquitto_pub and mosquitto_sub commands are available.

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IOTstack tutorial – adding a second drive

Problem statement

This issue has come up a few times on Discord. The question can be summarised like this:

My existing IOTstack installation is running out of space on my primary drive. I have another drive. How do I move the "volumes" directory to the new drive?

This example is based on a Raspberry Pi 4 which is booting from a 500GB USB3 SSD. I will show you how to use a 32GB USB3 "thumb drive" as the secondary drive and move ~/IOTstack/volumes onto it.

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IOTstack Tutorial: Logging CPU Temperatures

introduction

This gist answers a Discord question. It explains my approach to collecting CPU temperatures by sending the data as an MQTT payload.

I like to think of this approach as working with the MING (Mosquitto, InfluxDB, Node-RED, Grafana) paradigm rather than fighting against it (eg using approaches like SSH calling out of the Node-RED container).

The approach is not tied to the Raspberry Pi that is running IOTstack. If you have several Raspberry Pis, they can all log their temperatures to the Raspberry Pi running IOTstack using exactly the same mechanism.

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Tutorial: Debugging MQTT traffic flows in IOTstack

You have built an ESP32, ESP8266 or similar project. You are sure it is sending payloads via MQTT but the data doesn't seem to be arriving in Node-Red. You're at a bit of a loss as to what to do next.

This tutorial is specific to IOTstack where Mosquitto and Node-Red are running as Docker containers on a Raspberry Pi. Much of it is probably applicable to other environments but "your mileage may vary".

Related resources

• IOTstack Mosquitto documentation