I am trying to sign my private plugin, but it always says “Invalid signature” in grafana. I think the problem is, that I configured a root_url in the grafana config like root_url = %(protocol)s://%(domain)s/grafana/ and when I try to sign my plugin with npx @grafana/toolkit plugin:sign --signatureType private --rootUrls %(protocol)s://%(domain)s/grafana/ the command fails with Error: Error signing manifest: Value must be a URL: rootUrls[0]
As the error says, the rootUrl for signing needs to be a valid URL. It seems that the signing docs don’t take into account that the rootUrls can contain %(domain). I think you need to enter the expanded root URL to the signing command.