Can VPP plugins be implemented using Go?

Question

VPP provides the I/S for developing custom plugins that can be hooked into a graph of nodes. I've only seen examples for such plugins written in the C language, and was wondering whether other language, Go for instance, can also be used to write such plugins.

Answer 1

I have no idea what "VPP" is but nonetheless the answer is: "maybe"; here's why:

• Go code is able to interface with C libraries via its facility known as cgo.

  cgo is a multiple-faceted thing: it allows you to "export" certain Go functions in a certain way so that they can be called from the C side, and it allows you to call functions from the C side. It also allows you to write bits of inline C code to provide glue for the C side, when necessary.

• Since some time Go building toolset (at least its "reference" implementation) provides for compiling Go code into a static or dynamic library with C-compatible API.

  See this.

With these things in mind, in theory, it should be possible to do what you're after. Note some possible obstacles:

• Most of the time, if a "platform" allows you to write a "plugin" in C, it presupposes your plugin will make extensive use of the platform's own API.

  This usually means your plugin is supposed to include certain header files provided by the platform.

• The platform might also require your plugin to link against some platform-provided library (usually shared), or libraries.

cgo can do all of the above, but you will need to scrutinize the API provided by the platform and maybe write Go helpers to make its usage more natural for the Go code.

Building/linking issues (usually the locations of the header files and the libs) may also be a thing to solve.