import os
import processing
from qgis._core import QgsProject, QgsRasterLayer
from qgis.utils import iface
import uuid
gdbPath = 'path_to_my_gdb'
inputs = [
    {
        'layer': 'l1'
    },
    {
        'layer': 'l2'
    }
]

for i in inputs:
    buff = processing.run("native:buffer", {'INPUT':gdbPath+'|layername='+i['layer'] ,'DISTANCE':1000,'SEGMENTS':5,'END_CAP_STYLE':0,'JOIN_STYLE':0,'MITER_LIMIT':2,'DISSOLVE':False,'OUTPUT':'memory:'})
    print(buff['OUTPUT'].source()) #reurns: Polygon?crs=EPSG:2180&field...
    rast = processing.run("gdal:rasterize", {'INPUT':str(buff['OUTPUT'].source()),'FIELD':'OBJECTID','BURN':0,'UNITS':0,'WIDTH':6000,'HEIGHT':6000,'EXTENT':'544467.3539542153,555274.7214882236,210235.32501431665,216789.69148822338 [EPSG:2180]','NODATA':0,'OPTIONS':'','DATA_TYPE':5,'INIT':0,'INVERT':False,'OUTPUT':'/tmp/processing_5faae479f2bf42bbb6a3466fa8ac1332/test/OUTPUT_'+i['layer']+'.tif'})
    iface.addRasterLayer(rast['OUTPUT'],'test')