grpc client not receiving server streamed data

user_409942 0
Viewed 45

I'm trying to stream a nodejs child process output via grpc but keep on getting empty result.

Given my proto file.

syntax = "proto3";

package servicePackage;

service Mobile {
    rpc sign(Empty) returns (stream SHA256Info);
}

message Empty {}

message SHA256Info {
  string signature = 1;
}

And my grpc server code

function sign(call, callback) {
    const cp = require('child_process');
    var signature = "";
    let child = cp.exec('keytool -list -v -keystore android.keystore -alias android -storepass hardcodedstorepass -keypass hardcodedkeypass', { cwd: "./output" });

    child.on('exit', function (code, signal) {
        console.log('process exited with ' + `code ${code} and signal ${signal}`);
        call.end();
    });

    child.stdout.on('data', (data) => {
        if (data.includes("Certificate fingerprints:")) {
            var sig = data.substring(data.indexOf("SHA256:"));
            signature = sig;
            call.write({"SHA256Info": signature});
        }
    });

    child.stderr.on('data', (data) => {
        //console.error(`stderr:\n${data}`);
    });

}

And my grpc client code

const call = client.sign({});

call.on("data", signature => {
    console.log("STREAMED data => " + JSON.stringify(signature));
})

call.on("end", e => console.log("server done!"));

All I get is as a result is this:

{} //<------ empty result
server done!

My question is what am I doing wrong that is causing an empty result?

grpc node.js javascript
1 Answers

I succeeded by matching the exact members name given within the message SHA256Info

so Instead of

call.write({"SHA256Info": signature});

the correct return value should be

call.write({ "signature": signature });

here is the message structure

message SHA256Info {
  string signature = 1; //<--- you should return matching structure
}
user_4099420
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