Error Handling

Errors returned by the API follow the gRPC status code guidelines. This provides many niceties:

1. Language-native idioms (exceptions, return codes, etc.)
2. Easily mappable to HTTP error codes (used for HTTP access to RPCs)
3. Uses metadata rather than a global schema for more detailed errors

Example: Go

Unary RPCs

resp, err := example.GetOne(ExampleConfigRequest{Key: key})
if err != nil {
    log.Printf("failed to get %+v: %s\n", key, err)
    return err
}

Streaming RPCs

stream, err := example.GetAll(ExampleConfigStreamRequest{...})
if err != nil {
    log.Fatalf("failed to initialize GetAll stream: %s", err)
}
for {
    value, err := stream.Recv()
    if err == io.EOF {
        // all done
        break
    } else if err != nil {
        // stream was broken due to error
        log.Fatalf("stream was interrupted: %s", err)
    }

    log.Printf("%+v\n", value)
}

Example: Python

Unary RPCs

try:
    response = example_stub.Set(ExampleConfigSetRequest(...))
except grpc.RpcError as e:
    print('Set failed: {0}: {1}'.format(e.code(), e.details()))
    raise e

Streaming RPCs

try:
  for resource in example_stub.GetAll(ExampleConfigStreamRequest(...)):
    # process resource
except grpc.RpcError as e:
  print('GetAll failed: {0}: {1}'.format(e.code(), e.details()))
  raise e