Consul Service Mesh - pass parameters to an external envoy binary

I am trying to start the service mesh by running

consul config write -http-addr=myip:8500 proxy-defaults.json 

Contents of the proxy-defaults.json:

    "Kind": "proxy-defaults",
    "Name": "global",
    "MeshGateway": {
        "Mode": "local"

This is running within a Consul Container with a host network.

how do i pass the envoy parameters via an external config file?

consul connect envoy -http-addr=myip:8500 \
   -grpc-addr=myip:8502  -gateway=mesh \
   -expose-servers -register -bootstrap

The problem happens when I pass the bootstrap json to envoy via the command envoy --config-path /path/to/boostrap.json.

I get this error:

 error initializing configuration '/app/bootstrap.json': Unable to parse JSON as proto (INVALID_ARGUMENT:Expected a value.