I run into following issue when trying to display graphs from luci-app-statistics. I have browsed through forum topics but did not find a solution.
I am running OpenWrt 19.07.2 r10947-65030d81f3 on an x86 box.
Error message when trying to load a given graph, where XXX stands for plugin name, I get the error with every plugin:
Failed to execute call dispatcher target for entry '/admin/statistics/graph/XXX'. The called action terminated with an exception: /usr/lib/lua/luci/util.lua:221: attempt to get length of local 'str' (a nil value) stack traceback: /usr/lib/lua/luci/util.lua:221: in function 'split' .../luci/controller/luci_statistics/luci_statistics.lua:124: in function <.../luci/controller/luci_statistics/luci_statistics.lua:114> (tail call): ?
The only thing I modified from out-of-box config is that I set a different directory than /tmp for the RRDTool plugin (/opt/wdir/rrd/, I can see that there is now a folder in there containing folders name after plugins, which contain an .rrd file).
I have checked through Luci that collectd and luci_statistics are started.
I also checked
ls /etc/rc*.d K10collectd S00sysfixtime S19firewall S80collectd K10gpio_switch S00urngd S19mwan3 S80ucitrack K50dropbear S10boot S20network S94gpio_switch K85odhcpd S10system S30adblock S95done K89log S11sysctl S35odhcpd S96led K90boot S12log S50cron S98sysntpd K90network S12rpcd S50sqm S99sudo K90sysfixtime S19dnsmasq S50uhttpd S99urandom_seed K90umount S19dropbear S79luci_statistics
The storage directory and all its parent directories are world readable (they are 755 all the way to the top). I am not storing anything on a USB drive, the x86 box has enough disk space on the SSD.
I have read the startup scripts, total newbie here, and only "weird" thing I have seen is that (no change from my side) /etc/init.d/collectd creates a collectd.conf link in /tmp to /etc/collectd.conf and that /etc/init.d/luci_statistics itself replaces /etc/collectd.conf with a link to /var/etc/collectd.conf.
Don't know in which order this is being done (from above luci_statistics starts first) but when I check, the links are indeed present and 777, so I guess this is being processed in the correct order upon startup and with correct permissions.
From what I have read, the error is likely related to read permissions but these seem to be correct so I am at loss.
Sorry I am quite new to Linux. If anyone has a clue they are willing to share I already express my gratitude.