Crafting Sleek C++ Docker Containers: A Beginner's Guide

Let's embark on a journey to encapsulate the quintessence of modern C++ application deployment. In the realm of programming, the 'Hello, World!' program stands as a timeless beacon for beginners. Here, we elevate this simple tradition into the containerized cosmos with Docker.

// main.cpp
#include <iostream>

int main() {
    std::cout << "Hello, World!" << std::endl;
    return 0;
}

Accompanying our C++ script is its orchestration maestro, the CMakeList:

# CMakeLists.txt
cmake_minimum_required(VERSION 3.9.5)
project(sample_app)

set(CMAKE_CXX_STANDARD 14)

add_executable(sample_app main.cpp)

On your local machine, this minimalist CMake project performs flawlessly. Yet, there exists a more elegant and shareable form of this application's existence—within the confines of a Docker container.

The Art of Compiling in Docker Containers

Why whisper your code into a Docker container, you ask? Imagine a world where compatibility woes are folklore and dependency hell is a myth. Docker containers make this utopia a reality.

Now, let's delve into the architecture of a Dockerfile that employs the ingenious multi-stage build. Picture it as a two-act play: the first stage (build-env) is the diligent builder, compiling your application only to take a final bow and exit stage left. The second act reveals the star of the show—a pristine Docker image cradling your freshly minted application.

FROM alpine AS build-env

RUN apk --no-cache add cmake clang clang-dev make gcc g++ libc-dev libstdc++ linux-headers git postgresql-libs

ADD . /app
RUN cd /app && mkdir cmake-build-release && cd cmake-build-release

RUN cd /app/cmake-build-release && cmake ../ && make
RUN cd /app/cmake-build-release && ./sample_app

FROM alpine
RUN apk --no-cache add libstdc++ postgresql-libs
RUN apk update && apk add ca-certificates && rm -rf /var/cache/apk/*
WORKDIR /app

COPY --from=build-env /app/cmake-build-release/* /app/

ENTRYPOINT ["/app/sample_app"]

With your Docker container set into motion, 'Hello, World!' gracefully graces your screen—proof that your journey into containerized C++ applications has begun with resounding success.

Now that you've glimpsed the power of Docker in your C++ endeavors, may this guide be your ally as you navigate the vast seas of application deployment. Bon voyage!