I can confirm that above steps for running the plugin in grafana without docker is working on my raspberry PI 3B+ with the latest version of grafana (v 7.0.6)
In my case, editing the grpc-plugin.ts file was not needed (the file did not exist)
However, I did have to add another step. After restarting grafana and checking the the log with systemctl status grafana-server.service, I received following error:
"Failed to load plugin" logger=plugins error="plugin \"grafana-image-renderer\" is unsigned" pluginPath=/var/lib/grafana/plugins/grafana-image-renderer
Apparently, the compiled plugin is not signed. I used following workaround to get unsigned plugins working:
sudo nano /etc/grafana/grafana.ini
And then add the following line in the end:
[plugins]
allow_loading_unsigned_plugins = "grafana-image-renderer"
This allows grafana to run the unsigned image renderer plugin. Another option could be to get a signed version of the plugin, but I have no idea on how to do that.
I also had to install the chromium browser as already pointed out in this thread.
The image rendering is working fine now, but it does take ~5 secs for the image to appear