Update instructions for flat node usage

pull request solves issues #63 #64 #65

Dockerfile

@@ -87,6 +87,8 @@ RUN cmake .. \
   && make -j $(nproc)
 USER root
 RUN make install
+RUN mkdir /nodes \
+    && chown renderer:renderer /nodes
 USER renderer
 
 # Install and test Mapnik

README.md

@@ -139,6 +139,18 @@ docker run \
     run
 ```
 
+### CACHE
+
+The import and tile serving processes use 800 MB RAM cache by default, but this number can be changed by option -C. For example:
+```
+docker run \
+    -p 80:80 \
+    -e "OSM2PGSQL_EXTRA_ARGS=-C 4096" \
+    -v openstreetmap-data:/var/lib/postgresql/10/main \
+    -d overv/openstreetmap-tile-server \
+    run
+```
+
 ### AUTOVACUUM
 
 The database use the autovacuum feature by default. This behavior can be changed with `AUTOVACUUM` environment variable. For example:
@@ -153,15 +165,7 @@ docker run \
 
 ### Flat nodes
 
-If you are planning to import the entire planet or you are running into memory errors then you may want to enable the `--flat-nodes` option for osm2pgsql. This option takes a path to a file that must be persisted so we should first set up a volume with the right permissions:
-
-```
-docker run -it -v openstreetmap-nodes:/nodes --entrypoint=bash overv/openstreetmap-tile-server
-$ chown renderer:renderer -R /nodes
-$ exit
-```
-
-You can then use it during the import process as follows:
+If you are planning to import the entire planet or you are running into memory errors then you may want to enable the `--flat-nodes` option for osm2pgsql. You can then use it during the import process as follows:
 
 ```
 docker run \
@@ -173,6 +177,8 @@ docker run \
     import
 ```
 
+>Note that if you use a folder other than `/nodes` then you must make sure that you manually set the owner to `renderer`!
+
 ### Benchmarks
 
 You can find an example of the import performance to expect with this image on the [OpenStreetMap wiki](https://wiki.openstreetmap.org/wiki/Osm2pgsql/benchmarks#debian_9_.2F_openstreetmap-tile-server).

openstreetmap-tiles-update-expire

@@ -22,7 +22,7 @@ OSM2PGSQL_BIN=osm2pgsql
 TRIM_BIN=/home/$ACCOUNT/src/regional/trim_osc.py
 
 DBNAME=gis
-OSM2PGSQL_OPTIONS="-d $DBNAME -G --hstore --tag-transform-script /home/renderer/src/openstreetmap-carto/openstreetmap-carto.lua -C 2048 --number-processes ${THREADS:-4} -S /home/renderer/src/openstreetmap-carto/openstreetmap-carto.style"
+OSM2PGSQL_OPTIONS="-d $DBNAME -G --hstore  ${OSM2PGSQL_EXTRA_ARGS} --tag-transform-script /home/renderer/src/openstreetmap-carto/openstreetmap-carto.lua --number-processes ${THREADS:-4} -S /home/renderer/src/openstreetmap-carto/openstreetmap-carto.style"
 
 #------------------------------------------------------------------------------
 # When using trim_osc.py we can define either a bounding box (such as this

run.sh

@@ -56,7 +56,7 @@ if [ "$1" = "import" ]; then
     fi
 
     # Import data
-    sudo -u renderer osm2pgsql -d gis --create --slim -G --hstore --tag-transform-script /home/renderer/src/openstreetmap-carto/openstreetmap-carto.lua -C 2048 --number-processes ${THREADS:-4} ${OSM2PGSQL_EXTRA_ARGS} -S /home/renderer/src/openstreetmap-carto/openstreetmap-carto.style /data.osm.pbf
+    sudo -u renderer osm2pgsql -d gis --create --slim -G --hstore --tag-transform-script /home/renderer/src/openstreetmap-carto/openstreetmap-carto.lua --number-processes ${THREADS:-4} ${OSM2PGSQL_EXTRA_ARGS} -S /home/renderer/src/openstreetmap-carto/openstreetmap-carto.style /data.osm.pbf
 
     # Create indexes
     sudo -u postgres psql -d gis -f indexes.sql