Reputation: 21
I am trying to run a simple GRPC client-server code in raspberri Pi running Raspbian os.
Language that i am using -C# dotnet core (2.1)
I downloaded a sample project from here.
This is a dotnet core project . I am able to run it in Windows environment, i am also able to modify .proto file in this code and run successfully.
I published the solution as it is with command
{ dotnet publish -r linux-arm }
When tried running same on Rpi, i am getting exception. Attached screenshot has the details of it.
Any help to get through this would be of great use
Upvotes: 2
Views: 1248
Reputation: 5097
tl;dr The problem is the libgrpc_csharp_ext native library which currently does not get compiled and built for the arm7 processor. I've compiled it (on a pi) for arm7 and released a nuget package to bridge the gap until they support it all the way: https://www.nuget.org/packages/libgrpc_csharp_ext.arm7/
I'll update with a link to a blog post when I finish getting the rest of the tooling and template finished I'm working on.
fuller explanation: the Grpc.Core nuget package contains the native libgrpc_csharp_ext library that the dotnet implementation of grpc loads in NativeExtensions.cs then maps with PInvoke in NativeMethods.Generated.cs. Inspecting that package, you'll see a version of that library in each /runtimes/[win, osx, linux]/native folder. Unfortunately, no linux-arm version of the library is included. However, in the code, if the platform is linux, it will try to load the static library using the name as formatted here. Dissect that a little and you'll see that as of right now, any 'linux' platform that isn't '64bit' (which despite the proc on the pi being 64 bit, the distro of linux you're using on there, including raspbian, likely isn't) will look for libgrpc_csharp_ext.x86.so. When you dotnet publish -r linux-arm
, you'll see that library there in the build output, but unfortunately, it's the wrong one (I think publish just grabs 'the closest one' when it can't find a specific library in the runtimes folder).
The nuget package I created above is compiled for arm7 - I actually cloned the grpc repo onto a pi and peeled away enough of the /csharp build to just cmake the libgrpc_csharp_ext. The 'trick' the package uses is to put the library in runtimes/linux-arm/native folder within the package, which dotnet core recognizes when publishing and pulls into the build output - but the library is still named libgrpc_csharp_ext.x86.so because of the way NativeMethods.cs formats the library name.
Upvotes: 6