elixxir/comms

This library implements functionality for communications operations in the xx network system.

How to run tests

First, make sure dependencies are installed into the vendor folder by running glide up. Then, in the project directory, run go test ./....

If what you're working on requires you to change other repos, you can remove the other repo from the vendor folder and Go's build tools will look for those packages in your Go path instead. Knowing which dependencies to remove can be really helpful if you're changing a lot of repos at once.

If glide isn't working and you don't know why, try removing glide.lock and ~/.glide to brutally cleanse the cache.

Regenerate Protobuf File

To regenerate the mixmessage.pb.go file, first install gRPC:

go get -u google.golang.org/grpc

Then install protocol buffers v3 as follows:

• The simplest way to do this is to download pre-compiled binaries for your platform (protoc-[version]-[platform].zip) from here: https://github.com/google/protobuf/releases
• Unzip and move the protoc binary in the bin directory to some logical location (e.g. /usr/local/bin on Mac OS X)
• Update the environment variable PATH to include the path to the protoc binary file you moved as follows:
• Find your .bash_profile file and add the following line (if it isn't already there) with the path set to wherever you placed the protoc binary: export PATH=/usr/local/bin:$PATH

Next, install the protoc plugin for go with the following command:

go get -u github.com/golang/protobuf/protoc-gen-go@v1.3.5

This will add the plugin to your go directory in a bin folder. You must add this to your PATH variable in your .bash_profile, so again find your .bash_profile file and make sure your GOPATH is defined (on Mac OS the default is: export GOPATH=$HOME/go).

If GOPATH isn't defined, then add a line like the above defining it (replacing $HOME/go with the path of your go directory). Finally add the following line to your .bash_profile:

export PATH=$PATH:$GOPATH/bin

Everything should be installed now. Check by running protoc-gen-go in a terminal. It should hang with no errors if everything is installed correctly. Now navigate to the comms project directory and run the following command in the terminal in order to regenerate the mixmessage.pb.go file:

go get -u github.com/golang/protobuf/protoc-gen-go@v1.3.5
protoc -I vendor/ -I mixmessages/ mixmessages/mixmessages.proto --go_out=plugins=grpc:mixmessages

Repository Organization

This repository is organized into 4 key folders:

1. mixmessages - contains the gRPC proto spec file and the file generated from that, along with any future shared helper functionality.
2. client - client functions for proper cmix clients.
3. node - gRPC endpoints hosted by cMix servers.
4. gateway - gateway endpoints and functions

Note that gateway and node are organized similarly. The endpoints.go file contains gRPC endpoint implementations, and the handler.go file contains the handler interface used by the endpoint implementations as well as the implementation struct.

Adding Network Endpoints

To add an endpoint, you need to make changes to handler.go and endpoint.go. You will also need to add a client function to call your new endpoint in the repo where the client is implemented.

handler.go:

1. Add your function to the interface.
2. Add it to the implementationFunctions struct.
3. Add the "Unimplemented warning" version of the function to NewImplementation()
4. Add the wrapper call to s.Functions.FUNCNAME(...) at the bottom to implement the interface for Implementation struct.

endpoint.go:

1. Add the gRPC implementation which calls the function through the handler.

Client Function:

1. Implement the client call either via a new module or an existing module. It should go in the location where the module is the client (i.e., if the node calls to the gateway, it goes in node)