C++ for the Web with Drogon

Drogon is currently the fastest web server in the world. If you already know a bit of C++, it wouldn’t hurt to try it out. I personally think drogon is great, however I do find its documentation somewhat lacking which is all the more reason to contribute to them. If you find that drogon is right for you, please consider contributing to / sponsoring their project.

In this blog, we’ll see how we can set up a basic REST API using drogon and CMake.

The code snippets I’ve provided apply to macOS and Linux. However, you can still follow along if you’re on windows and have worked with CMake and VS before.

Project Setup

If you’re like me and you don’t mind using CMake with submodules, we can set up drogon like so:

Get the pre-requisite libraries installed in accordance with the official documentation. For macOS, I had to install ossp-uuid and jsoncpp.

Create a CMakeLists.txt in your project root.

touch CMakeLists.txt

Initialize Git in your project root.

git init

Add drogon as a submodule

git submodule add https://github.com/drogonframework/drogon.git external/drogon

Pull drogon’s submodules (trantor)

git submodule update --init --recursive

At this point you’ve got your dependencies setup. Let’s go ahead and add some code for our basic REST API.

Create a new directory for our source files

mkdir src

And add our entrypoint

touch src/main.cpp

Here’s a basic CMakeLists.txt file that will build our project

cmake_minimum_required(VERSION 3.25.2)

    VERSION 0.1
    DESCRIPTION "Drogon CMake Tutorial"

# compiler flags

add_executable(${PROJECT_NAME} src/main.cpp)


target_link_libraries(${PROJECT_NAME} PRIVATE drogon)

And this will be our src/main.cpp

#include <drogon/drogon.h>
int main()
    using namespace drogon;
        .addListener("", 8080)
            [](const HttpRequestPtr& req,
                std::function<void(const HttpResponsePtr&)>&& callback,
                const std::string& name)
                Json::Value json;
                json["result"] = "ok";
                json["message"] = std::string("hello,") + name;
                auto resp = HttpResponse::newHttpJsonResponse(json);
            { Get,"LoginFilter" })

Building and Running the App

So far your directory structure should look something like this:

├── CMakeLists.txt
├── external
│   └── drogon
└── src
    └── main.cpp

4 directories, 2 files

Go ahead and create a directory to house our build files

mkdir build && cd build

Now lets generate the Makefile using

cmake ..

and now to compile our application,

make -j$(nproc)

Hopefully after all this, you should find an executable called drogontutorial in the build directory.

let’s run this file to start our server.


Now, your server should be listening on port 8080. Test it out by sending your name to /hello

curl http://localhost:8080/hello?name=yourname

And just like that you’ve got a starter project to write your own REST APIs in C++.

If you find this nice, do check out their examples on github.

Until next time!