using_grpcc_occ.md

OCC API debugging with grpcc

In order to talk to the AliECS core we can use coconut, or we can make calls directly with a gRPC client, such as grpcc.

Assuming you have installed Node.js and npm (on CC7 $ sudo yum install http-parser nodejs npm), the installation with npm is straightforward.

$ sudo yum install http-parser nodejs npm
$ npm install -g grpcc # it can take a few minutes due to grpc build

In a new terminal, we go to the occ directory (not the build dir) and connect via gRPC:

$ grpcc -i --proto protos/occ.proto --address 127.0.0.1:47100

If all went well, we get an interactive environment like so:

Connecting to occ_pb.Occ on 127.0.0.1:47100. Available globals:
client - the client connection to Occ
stateStream (StateStreamRequest, callback) returns StateStreamReply
getState (GetStateRequest, callback) returns GetStateReply
transition (TransitionRequest, callback) returns TransitionReply
printReply - function to easily print a unary call reply (alias: pr)
streamReply - function to easily print stream call replies (alias: sr)
createMetadata - convert JS objects into grpc metadata instances (alias: cm)
printMetadata - function to easily print a unary call's metadata (alias: pm)
Occ@127.0.0.1:47100>

Let's try to send some commands. State changes will be reported in the standard output of the process.

Occ@127.0.0.1:47100> client.getState({}, pr)
{
"state": "STANDBY"
}
Occ@127.0.0.1:47100> client.transition({srcState:"STANDBY", transitionEvent:"CONFIGURE", arguments:[]}, pr)
{
"trigger": "EXECUTOR",
"state": "CONFIGURED",
"transitionEvent": "CONFIGURE",
"ok": true
}
Occ@127.0.0.1:47100> client.getState({}, pr)
{
"state": "CONFIGURED"
}
Occ@127.0.0.1:47100> client.transition({srcState:"CONFIGURED", transitionEvent:"START", arguments:[]}, pr)
{
"trigger": "EXECUTOR",
"state": "RUNNING",
"transitionEvent": "START",
"ok": true
}
Occ@127.0.0.1:47100> client.transition({srcState:"RUNNING", transitionEvent:"STOP", arguments:[]}, pr)
{
"trigger": "EXECUTOR",
"state": "CONFIGURED",
"transitionEvent": "STOP",
"ok": true
}
Occ@127.0.0.1:47100> client.transition({srcState:"CONFIGURED", transitionEvent:"EXIT", arguments:[]}, pr)
{
"trigger": "EXECUTOR",
"state": "DONE",
"transitionEvent": "EXIT",
"ok": true
}
# no further commands possible, EXIT stops the process