docker-hello-world.md

Docker Hello World

HelloWorld Cheatsheet for

• installing Docker
• creating a small small c-program
• creating a Docker Image containing and executing that c file with Dockerfile

Installing

# 2 options:
# this provided by the Linux distribution
sudo apt install docker.io
# this is provided by docker.inc
sudo apt-get install docker-ce docker-ce-cli containerd.io
#

Install everything required for compiling basic software written in C and C++.

sudo apt install build-essential

Create "hello.c"

#include <stdio.h>

int main() {
    printf("Hello World!\n");
    return 0;
}

Compile C-File

gcc -o hello --static hello.c

Create Dockerfile

• create a file called "Dockerfile" with following content:

# indicates that this image will start from an empty image
FROM scratch

# copies a file hello to the root filesystem
COPY hello /

# executes the hello program
CMD ["/hello"]

Create Docker Image

sudo docker image build -t helloimage .

Check Images and Containers

sudo docker images
sudo docker ps

Start Docker Container

docker run helloimage