Contributing to Meshery Adapters

Meshery Adapters are the Extension Points in Meshery’s architecture. Their design, the process of creating a new adapter is documented in Extensibility: Meshery Adapters.

With the CONTRIBUTING.md in mind, understand that development follows the usual fork-and-pull request workflow described here, see also GitHub Process. On forking GitHub deactivates all workflows. It is safe and good practice to activate them such that the code is validated on each push. This requires that branches filter for “on push” is set to ‘**’ to be triggered also on branches containing ‘/’ in their name. The actions are parameterized using secrets (see Build & Release Strategy). The Docker image is only built and pushed to Docker Hub if a tag is pushed and the corresponding authentication information is configured. The only secret that should be set in each fork is GO_VERSION, specified in Build & Release Strategy, otherwise, the corresponding action’s default version is used.

Each commit has to be signed off, see Contributing Overview.

Running an adapter as a container

Testing your local changes running as a container can be accomplished in two ways:

1. Define the adapter’s address in the UI: Unless the running container is named as specified in the docker-run target in the Makefile, the container has to be removed manually first. Then, run make docker followed by make docker-run. Then, connect to the adapter in the UI in “Settings > Adapters” using localhost:<port> if the meshery server is running as a binary, or : if it is running as a docker container.
2. Using mesheryctl: In ~/.meshery/meshery.yaml, change the tag specifying the image of the adapter to “latest”. Run make docker, followed by mesheryctl system start --skip-update. This assumes mesheryctl system start has been executed at least once before.

Running an adapter as a process

Another way to test your local changes is to run the adapter as a process. To do this, clone the meshery/meshery repository, and start Meshery Server using make server. Start the adapter from your IDE, or by executing make run. Then, in Meshery UI, add the adapter using “localhost:”.

Creating a new Meshery Adapter

Meshery uses adapters to manage and interact with different cloud native infrastructure. Meshery adapters are written in Go. Whether you are creating a new adapter or modifying an existing adapter, be sure to read the Meshery Adapters design specification. For new adapters, start with the Repository Template(https://github.com/layer5io/layer5-repo-template).

1. Get the proto buf spec file from Meshery repo: wget https://raw.githubusercontent.com/layer5io/meshery/master/meshes/meshops.proto
2. Generate code
   1. Using Go as an example, do the following:
      • adding GOPATH to PATH: export PATH=$PATH:$GOPATH/bin
      • install grpc: go get -u google.golang.org/grpc
      • install protoc plugin for go: go get -u github.com/golang/protobuf/protoc-gen-go
      • Generate Go code: protoc -I meshes/ meshes/meshops.proto --go_out=plugins=grpc:./meshes/
   2. For other languages, please refer to gRPC.io for language-specific guides.
3. Implement the service methods and expose the gRPC server on a port of your choice (e.g. 10000).

Tip: The Meshery Adapter for Istio is a good reference adapter to use as an example of a Meshery Adapter.