Sending http request to server running on a VirtualBox linux machine from the host machine

I currently am developing a REST server using Microsoft's cpprestsdk called Casablanca.

I have the server running on a linux virtual machine using Oracle's VirtualBox.

I have the VM set up to use bridged adapter networking, and can successfully SSH into the machine so I know that it is possible to send an http request to my server.

I have the endpoint of my server currently set to:

http://localhost:4200/api"

See the code in my main.cpp below:

int main() {
    cout << "Starting Server" << endl;

    TransactionController server;
    server.setEndpoint("http://localhost:4200/api");
    server.initHandlers();

    try {
        server.openServer().wait();
        cout << "Server listening at: " << server.getEndpoint() << endl;

        // figure out how to keep server running without this?
        while (true);
    }
    catch(exception &e) {
        cout << "--- ERROR DETECTED ---" << endl;
        cout << e.what() << endl;
    }


    // this doesn't get reached bc of the while(true)
    server.closeServer().wait();

    return 0;
}

(I know that this isn't the cleanest implementation, but I am just trying to get something off the ground so I can test functionality, feel free to comment on how I can improve that code snippet if you have anything to say)

So if I log into my VM and do a curl GET request on the guest machine it completes successfully and I receive my response as intended.

Example curl:

curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://localhost:4200/api

Now my question is, how can I do the same request but from my host computer, using an HTTP client such as Postman or Advanced Rest Client?

I am not sure what I would put as the request URL when attempting to query my server running on my guest machine from my host machine.

Using ifconfig I know my ip address of the guest machine is:

10.0.0.157

I can SSH into my VM using this address, so I know this is the correct address of my guest machine.

I do not know how I can send my http requests to this machine that is running my server, however.

I am not an expert in networking, or casablanca for that matter, so any guidance or pointers in the right direction would be greatly appreciated. Thank you for your time!

You've bound your server to localhost so it is only available from localhost. I don't know what TransactionController::setEndpoint does but you probably need to do one of the following:

server.setEndpoint("http://10.0.0.157:4200/api"); // bind to only 10.0.0.157
server.setEndpoint("http://0.0.0.0:4200/api"); // bind to all ipv4 adresses
server.setEndpoint("http://*:4200/api"); // bind to all addresses

Which of the above will work will depend on the implementation of setEndpoint.