always pull Docker images before using them

makefile

@@ -28,14 +28,14 @@ FILTERED = BW BB
 gtfs : data/www/index.html $(MERGED_WITH_FLEX:%=data/gtfs/%.merged.with_flex.gtfs.zip) $(MERGED:%=data/gtfs/%.merged.gtfs.zip) $(FILTERED:%=data/gtfs/DELFI.%.gtfs.zip)
 
 # Shortcuts for the (dockerized) transform/merge tools.
-OSMIUM = docker run -i --rm -v $(HOST_MOUNT)/config/osm:$(TOOL_CFG) -v $(HOST_MOUNT)/data/osm:$(TOOL_DATA) mfdz/pyosmium osmium
-OSMIUM_UPDATE = docker run -i --rm -v $(HOST_MOUNT)/data/osm:$(TOOL_DATA) mfdz/pyosmium pyosmium-up-to-date
-OSMOSIS = docker run -i --rm -v $(HOST_MOUNT)/config/osm:$(TOOL_CFG) -v $(HOST_MOUNT)/data/osm:$(TOOL_DATA) mfdz/osmosis:0.47-1-gd370b8c4
-TRANSFORM = docker run -i --rm -v $(HOST_MOUNT)/config/gtfs-rules:$(TOOL_CFG) -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA) mfdz/onebusaway-gtfs-modules java -Xmx20g -jar onebusaway-gtfs-transformer-cli.jar
-PFAEDLE = docker run -i --rm -v $(HOST_MOUNT)/config:$(TOOL_CFG) -v $(HOST_MOUNT)/data/osm:$(TOOL_DATA)/osm -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA)/gtfs adfreiburg/pfaedle
-MERGE = docker run -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA)/gtfs --rm mfdz/onebusaway-gtfs-modules java -Xmx18g -jar onebusaway-gtfs-merge-cli.jar --file=stops.txt --duplicateDetection=identity 
-GTFSVTOR = docker run -i --rm -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA)/gtfs -v $(HOST_MOUNT)/data/www:$(TOOL_DATA)/www -e GTFSVTOR_OPTS=-Xmx8G mfdz/gtfsvtor
-GTFSTIDY = docker run -i --rm -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA)/gtfs derhuerst/gtfstidy
+OSMIUM = docker run --pull always -i --rm -v $(HOST_MOUNT)/config/osm:$(TOOL_CFG) -v $(HOST_MOUNT)/data/osm:$(TOOL_DATA) mfdz/pyosmium osmium
+OSMIUM_UPDATE = docker run --pull always -i --rm -v $(HOST_MOUNT)/data/osm:$(TOOL_DATA) mfdz/pyosmium pyosmium-up-to-date
+OSMOSIS = docker run --pull always -i --rm -v $(HOST_MOUNT)/config/osm:$(TOOL_CFG) -v $(HOST_MOUNT)/data/osm:$(TOOL_DATA) mfdz/osmosis:0.47-1-gd370b8c4
+TRANSFORM = docker run --pull always -i --rm -v $(HOST_MOUNT)/config/gtfs-rules:$(TOOL_CFG) -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA) mfdz/onebusaway-gtfs-modules java -Xmx20g -jar onebusaway-gtfs-transformer-cli.jar
+PFAEDLE = docker run --pull always -i --rm -v $(HOST_MOUNT)/config:$(TOOL_CFG) -v $(HOST_MOUNT)/data/osm:$(TOOL_DATA)/osm -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA)/gtfs adfreiburg/pfaedle
+MERGE = docker run --pull always -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA)/gtfs --rm mfdz/onebusaway-gtfs-modules java -Xmx18g -jar onebusaway-gtfs-merge-cli.jar --file=stops.txt --duplicateDetection=identity 
+GTFSVTOR = docker run --pull always -i --rm -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA)/gtfs -v $(HOST_MOUNT)/data/www:$(TOOL_DATA)/www -e GTFSVTOR_OPTS=-Xmx8G mfdz/gtfsvtor
+GTFSTIDY = docker run --pull always -i --rm -v $(HOST_MOUNT)/data/gtfs:$(TOOL_DATA)/gtfs derhuerst/gtfstidy
 
 
 # Download/Update OSM extracts from Geofabrik
@@ -104,7 +104,7 @@ data/gtfs/%.merged.with_flex.gtfs: data/gtfs/%.merged.gtfs.zip
 	unzip -d $@ $<
 	$(info patching GTFS-Flex data into the GTFS feed)
 	# todo: pick flex rules file based on GTFS feed
-	docker run -i --rm -v $(HOST_MOUNT)/data/gtfs/$(@F):/gtfs derhuerst/generate-gtfs-flex:4 stadtnavi-herrenberg-flex-rules.js
+	docker run --pull always -i --rm -v $(HOST_MOUNT)/data/gtfs/$(@F):/gtfs derhuerst/generate-gtfs-flex:4 stadtnavi-herrenberg-flex-rules.js
 
 data/gtfs/%.merged.with_flex.gtfs.zip: data/gtfs/%.merged.with_flex.gtfs
 	rm -f $@