Hello everyone!
There is an ASP.NET Core Web API running on Fly in a container. The API has to invoke Protobuf compiler to generate .cs files (and use Roslyn next, but that’s the other story). And the problem is I catch an exception saying “Access denied” when this process is starting.
As the compiler I use pre-built Linux executable. I’ve tried to copy it from a web root path to a folder mounted to a volume, but no permission still.
This file isn’t deleted by Docker, and this approach works on my local machine (with .exe since I use Windows). I’m confused and don’t know where to start. Any help would be appreciated.
does your binary have the execute filesystem permission?
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Fly builders don’t package the container image with “Docker”, btw (as in there’s no cross platform virtualization). So, if you’re doing anything that requires Windows virtualization, I don’t think that would work on Fly (which runs the container on KVM’d amd64 Linux as-is). I may be wrong…
Can you share your dockerfile, if that’s okay?
Btw, Fly apps run as root user by default. And so, unless you change run-as user in the dockerfile, I’d imagine that there’s very little the app would get denied access to (stuff like, unavailable syscalls or capabilities or resources, say).
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Yup, that is the thing. I was a little confused by the fact that redeployment probably dropped my permissions before I move the executable to persistent storage. Rookie problems 
Thank you for your time!
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Thank you for educating me! Yes, you’re absolutely right about Windows virtualization - I face this fact, too, having some Windows-aimed modules.
There is no need in exposing dockerfile already since the problem was in permissions. Apparently, default access level for “random” executables restricts execution.
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