Plugin packages installed in bro clusters may deploy broken symlinks

[JonZeolla]

Plugins contain unconditionally loaded scripts that enable basic functionality, which are handled differently than non-plugin package's bro scripts. When plugin packages are installed in a bro cluster, there is the potential for the cluster to fail to start because those scripts are placed in $prefix/bro/lib/bro/plugins/packages/$package_name/scripts, which is a symlink to the state_dir. As far as I'm aware, bro-pkg does not replicate information to other cluster members.

I would expect either bro-pkg or broctl (via install) to transparently handle this situation, but I also would not expect those tools to touch a user's home directory.

In my situation, to fix this issue I chose to set state_dir to $prefix/bro/lib/bro-pkg, which is then automatically deployed by broctl install. I'm not sure what guarantees bro-pkg has, but for clustered environment I feel that this is a fairly clean solution (since all clusters that I'm aware of depend on broctl). I would not be a fan of replicating data stored in state_dir uniformly, given the current default is ~/.bro-pkg, but I am open to other solutions.