SituationYou edit vernemq.conf, only to find that your configuration is overwritten by VerneMQ on the next start (using the official Docker container).Specifically, the section with the listeners at the end of the file is “forced upon you”.SolutionVerneMQ is started using a script (start_vernemq). The script can be seen here:https://github.com/vernemq/docker-vernemq/blob/master/bin/vernemq.shThe important part is here:As you see, [...]
Some quick background information for anyone running into the same issues, and how to debug them.Error code 503This is the error code I am getting:Error during WebSocket handshake: Unexpected response code: 503.Set envoy logging to debugHere’s my docker-compose.yaml for envoy:version: '3.7' services: envoy: build: context: ./ dockerfile: Dockerfile container_name: penvoyage-morpheus-envoy ports: - "80:1080" - "443:1443" [...]
In my article yesterday I discussed the configuration & test of envoy for proxying websockets at length.Today I would like to add some additional information.correct syntax for websocket upgrade per routeYou can enable websocket upgrade per route. No need to add it globally:- name: envoy.http_connection_manager config: #upgrade_configs: # - upgrade_type: websocket stat_prefix: ingress_https use_remote_address: true [...]
Websockets are an exciting technology, allowing you to upgrade a HTTP connection to a long-running persistent binary connection, which you can use to send bi-directional messages.As an aside, the MQTT protocol can be transported using websockets – which is the only (?) way for a JavaScript client delivered by the website, for instance.In any case, [...]
The Paho documentation is unfortunately quite fragmented at the moment, and some links on Eclipse’s website do not work.Here are some working links (as of 05/2019):https://www.eclipse.org/paho/clients/js/https://www.eclipse.org/paho/files/jsdoc/index.htmlhttps://github.com/eclipse/paho.mqtt.javascriptAnd here’s a fantastic website by Steve:http://www.steves-internet-guide.com/using-javascript-mqtt-client-websockets/There is an important breaking change in the Paho namespace, where you will run into trouble using Steve’s code:“Previously the Client's Namepsace was Paho.MQTT, [...]
My goal / TLDRMy goal with this blog post is to explain how to set custom mountpoints for VerneMQ by modifying the shipped MongoDB auth Lua script (lua/auth/mongodb.lua).Setting a custom mountpoint is possible with VerneMQ not only by setting mountpoints manually for specific listeners (e.g. ports), but also programmatically during authorization in your scripts.I had [...]
When you extend your field definitions in the mongo_orm document classes, specifically with embedded documents, you might run into the following runtime (!) error:Exception: missing bson key: <name> (Exception)This is not an error in your code – your code is raising, because the database structure is not as it expects it to be!Here’s the sample [...]
IntroductionS.N.A.P. is a protocol for communication between several connected hosts. It provides:· addressing· flags· ack/nak request· error detection (different error detection methods available)It can be run over different media, including RS485. It is optimized for a small footprint (limited computing, memory resources), but scaleable depending upon your needs.Basically, if you want to connect several compute [...]
Abmessungen Raspberry PiEin Raspberry Pi 3B+ hat, als Vergleich, die Abmessungen: 85 mm x 56 mm für die Basisplatine. (USB & LAN, sowie andere Stecker ragen teilweise über die Platine hinaus). Hutschiene / DIN-SchieneHutschiene: TS35, U-förmiges Profil. Standarisierte Befestigungsschiene für Gehäuse, Racks, Schaltschränke, u.s.w. Sie wird vielfach in der Industrie eingesetzt. Einer der ersten Einsatzzwecke [...]