Development
Splitting envoy envoy.yaml configuration into multiple files (Docker only)
I am handling four different ports / cases with Envoy: IPv6 http IPv4 http IPv6 https IPv4 https For IPv6 and IPv4 the configuration is the same, whereas for http there is a different configuration than for https. To realize this, I have split my envoy configuration into several snippets, and add them together during…
WeiterlesenSynchronizing file uploads between browser windows
For PiCockpit, I am currently developing the Digital Nose app. This app requires an upload for the BSEC configuration file – which is binary data. Once the user uploads the file, it gets published via MQTT, and picockpit-client can use it to configure the BSEC AI algorithm to do gas detection. Here is a little…
WeiterlesenHow to restore images for a Shopify product you’ve overwritten accidentally by CSV file
Problem: (wrong handling of CSV files) Yesterday I wanted to bulk-edit products in Shopify, and to change the vendor. I used LibreOffice to select just the rows with the vendor in it, updated it, and uploaded only these updated rows as a new CSV to Shopify. The result was that Shopify dropped many variants, and…
WeiterlesenVuetify :: Open detail row programmatically
For the upcoming PiCockpit v2.0 release, I am preparing a GPIO application. The GPIO entries are table rows – and to configure them, we want to be able to access the detail row by clicking on the configure button: clicking either the chevron or the configure button will lead to the detail row opening: Here…
Weiterlesenenabling and disabling a systemd service in Python using DBus
The upcoming picockpit-client reacts to deletion events from the frontend by disabling it’s service (the application will stay installed, however). Similarly, when you decide to run picockpit-client connect again, the service will be re-enabled and started automatically for you. This is possible using the Python DBus interface. the DBus is a bus system for interacting…
WeiterlesenHow to set unique object ids in embedded documents across a MongoDB collection
MongoDB’s updateMany can be used to update all documents which are matched. Problem If, however, you want to set unique new ObjectIDs in your update, you would find that MongoDB sets the same ObjectID for every entry: db.getCollection(‘mypis_collectedpis’).updateMany({}, {$set: {apps: { “com.picockpit/core”: { meta: { version: “2.0”, name: “PiCockpit Core”, image: “”, description: “PiCockpit.com…
Weiterlesenswitching from JSON to MsgPack in a backwards compatible manner with Paho MQTT (JavaScript)
picockpit.com makes heavy use of MQTT. For the upcoming version 2.0 I have decided to switch it to MsgPack. Why MsgPack? MsgPack (actually called MessagePack – packages tend to use MsgPack) is a binary format, aimed at compatibility with JSON, but decreasing file size (which is good for saving bandwidth & server resources). Another advantage:…
Weiterlesenenvoy fix for serving big files from the backend / timeouts / aborted downloads
Customers were complaining about not being able to download big files from our websites (e.g. PiDoctor on PiCockpit.com). Initially I could not replicate the issue locally, the files seemed to be downloading fine. After further investigation I determined that the downloads were cutting out after a certain time – depending on your download speed, thus,…
WeiterlesenDealing with NIL in JSON::Any in Crystal Lang
One of the challenges when developing with Crystal is that it is not as forgiving about data types as, say, Python or Ruby. nil will keep you occupied. The following error message: cast from Nil to String failed, at /usr/share/crystal/src/json/any.cr:220:5:220 can be solved by: # cast to string, THEN check if it is nil if…
WeiterlesenChromium exit code -5
While running Chromium with chromium-browser –display=:0 https://www.picockpit.com will allow you to start Chromium from an SSH connection (and it will output to the main display in the X Server), this will fail when you try to run it with subprocess.Popen in Python: “command”: [“chromium-browser”, “–display=:0”, “https://picockpit.com”] (this is part of the JSON format I have…
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