I temporarily solved it by running as another user or changing the safe location (most of the time by environment variable) of f.e. the .npm folder to somewhere else.
As far as I can tell it has nothing much todo with the other problem and more with how the config map is mounted to the full directory and thus preventing write access to the full folder. Changing the folder permissions is not possible. Only way would be changing the $HOME variable to something else and thus having another save location.
For anyone looking, I ran into the same problem as well for the drone-plugin/docker or /gcr containers. There docker login only works if you have write access to $HOME/.docker. You have to set a custom $HOME to change the $HOME to allow write access.
the same problems occures when running the helm plugin (https://github.com/ipedrazas/drone-helm).
There, the root path is also hardcoded and unfortunately cannot be changed unless I will create my own fork of the plugin.
@bradrydzewski Does this issue have priority for you? Or will it be fixed in the next sprint?