Running .model3 files with PostgreSQL connections

Hi ​@hbrillon, 

While I'm not completely familiar with using QGIS Modeller with FME, I did have some success running it with the system caller. Here is the approach I used:

The model is simply reading in a pg point layer and clipping it with a polygon. The output is exported to another database.

Instead of using Copy as qgis_process command, I used copy as JSON to store the parameters.

I had to make one change to the copied JSON before it would run: adding user='...' and password='...' to the postgres connection string. The copied version doesn't include them (QGIS fills them in from the saved connection when you run in the app), and without them qgis_process failed with "Incorrect parameter value" on that input. I suspect this may be related to the "File could not be found" error you're seeing, since QGIS can't resolve the connection string without credentials. I also used full paths for any file inputs, since there's no open project for QGIS to resolve relative paths against.

For the actual command, I used:

"type "C:\qgis\test1b_model_postgis.json" | "C:\OSGeo4W\bin\qgis_process-qgis.bat" run "C:\Users\dylan.paterson_safe\AppData\Roaming\QGIS\QGIS3\profiles\default\processing\models\model.model3" - --verbose > "C:\qgis\out_fme.txt" 2>&1"

which created the table in the database.

Hope that helps!

Best, 
Dylan.

Hi ​@dylan.at.safe  and thank you for your reply. I am now aware that my problem likely has to do with the way Postgres is being authentified. However, embedding credentials in the script is not a good solution for me, as this flow will need to be able to run on any workstation within my team. A cleaner approach would be to have SystemCaller use the connection embedded in my workbench, as I understand those to be specific to each machine.

Your syntax for calling the variables as JSON and qgis_process from the OSGeo4W bin is interesting. I will try that next.