by ezs | Mar 10, 2023 | evilzenscientist
I’ve had a Microsoft Flow connector in production for a long time. It runs twice daily, reads the weather forecast for my location (Issaquah, WA), and if it’s forecast to be warm, sends an email to remind that plants need watering.
At some point recently, the flow stopped working correctly. It was triggering for Fahrenheit temperatures rather than Celsius. Cue twice daily emails when it’s cold outside.
I pulled apart the flow – and the Inputs for the connector had changed:
by ezs | Jan 15, 2023 | evilzenscientist
Note for myself – remember to switch the UEFI template to Microsoft UEFI Certificate Authority to allow booting from the ISO.
by ezs | Jan 13, 2023 | evilzenscientist
Deep joy working with Azure Function apps, and using timer triggers this last few weeks.
I’ve been working on a set of Azure Functions that fire on a schedule, to read information from across the Azure environment, and write the results to Cosmos DB. Simple enough.
The trigger is set as a Timer:
The timer takes an NCRONTAB format for when it fires.
The various pieces of documentation are pretty clear, and I’ve got a lot of familiarity with CRON running on Linux.
My initial schedule was 0 0 */8 * * * – which should fire every 8 hours.
Instead – some really variable and unreliable results. I found "8-ish" hours between triggers to be best case, often the whole function stopped firing. Restart the function, and "8-ish hours" later it fired.
After a bunch of reading and testing, I changed the schedule to 0 0 0/8 * * * – which fires at 00Z, 08Z, 16Z – so every 8 hours, but locked to midnight, 8.00am and 4.00pm UTC.
So far – so good.
This was a good NCRONTAB expression tester: NCrontab Online Expression Tester Evaluator (swimburger.net)
by ezs | Sep 19, 2022 | evilzenscientist
This blog (and several others) have been Azure hosted, on a monolithic SLES 15 virtual machine for a good few years.
I seem to have done the rounds on various flavours of Azure hosting. App Service with Project Nami, straight IaaS (like today), App Service with WordPress as a Microsoft provided service.
This last weekend I pulled the database out from the various blog VMs and moved that to a PaaS MySQL environment. It’s cheap, burstable, and seems more than performant for what I need. The other cool feature is VNET isolation – so the database engine is only accessible from my infrastructure running in Azure.
by ezs | May 1, 2022 | Solar
Introduction
In April 2022 I had a PV system installed, with a local Enphase Envoy as part of the configuration.
The Enphase Envoy acts as a management gateway for the Enphase system. Collecting, storing and forwarding data to Enphase for the consumer Enlighten datapool and application.
My installation consists of an IQ Combiner; but I believe these instructions are valid for any Envoy running software greater than version 7. At the time of writing my Envoy is running D7.0.85.
Some history
I was interested in the raw data coming from the PV system. During vendor selection I reviewed the access and APIs available; and Enphase seemed to have a good mix of capabilities.
At some point in late 2021/early 2022 access to a local Envoy gateway was changed to require a JWT access token. This caused many home automation and data logging integrations to break. The documentation from Enphase showed how to interactively get the token and login. I found no documentation on doing this automatically through code.
After much reading, reviewing multiple blogs and github repos, and trial and error – I have this now working.
Authentication flow
Firstly, there’s a lot of head scratching on this approach from Enphase. Yes – it protects access behind a token, but it’s all intended for interactive work. I can only surmise that the market for this is not the home integrator or API data scraper. I see Enphase pushing that persona towards the Enlighten API v4 – which has a different set of issues (which I’ll write about in the future).
So the flow:
- login, using Enphase username/password, to the Enphase Entrez token service
- get a JWT access token
- post this JWT to the local envoy
- get data
The third step of this, posting the JWT to /auth/check_jwt, does not seem to be documented anywhere.
Also, and most troubling, the JWT itself is returned as part of the body of a html page. Some regex is needed to extract the specific text string. This has risk in the event that the html document structure changes in the future.
I posted a sample PowerShell script here.
Using this approach, I now have data being pulled from the local IQ Combiner, parsed, posted to a NoSQL database, and then graphed.
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