Deployment / Configuration gtfsrthttps2mqtt

[hbruch]

VVS provides vehicle positions via https://gtfsr-vehpos.vvs.de/.

For these, the digitransit vehicle positions mqtt service should be set up, so digitransit can display vehicles positions for all vehicles for which the VVS provides them.

Note for digitransit and app: the vehicles feed does no provide bearing, so vehicles need to be displayed without direction indicator.

Note further, that VVS calculates estimated positions from timetable, and if available, realtime trip updates. The gtfs-rt feed provides no information, if the position is estimated from realtime data or not, so the positions are potentially unreliable.

Outdated services like delay-prediction-service should be uninstalled/removed from digitransit.

[leonardehrenfried]

Where do you see this being deployed?

• on the infrastructure host
• on each API host

In any case I will need new DNS entries, for example mqtt.stadtnavi.eu, vehiclepositions.stadtnavi.eu or mqtt.dev.stadtnavi.eu.

[hbruch]

Could one service serve mulitple vehicleposition-feeds? Then I'd opt for the infrastructure host. Or do you see advantages using the API host?

[leonardehrenfried]

If we had two data feeds we could use a dev/prod deployment but we don't. Besides we don't plan to make any chances to the stack ever, so having it on infra suits me very well.

If we wanted several feeds we would have to run several instances of gtfsrthttps2mqtt and that's of course possible.

[leonardehrenfried]

There are very many 500 errors when calling this service, roughly about 50%. My guess is that a load balancer doesn;t have a health check and sends half its traffic to a unhealthy instance.

[leonardehrenfried]

Despite the 500s I managed to set up the infrastructure today.

You can try it out yourself with

npm install mqtt -g
mqtt subscribe -h vehiclepositions.stadtnavi.eu -p 443 -l wss -v -t "#"