The minimum container image in the whole world!

 1. All files needed

$ ls

Dockerfile  hello.c

$ cat hello.c

#include <stdio.h>

int main(int argc, char** argv)

{

    printf("Hello container!\n");

    return 0;

}

$ cat Dockerfile

FROM scratch

WORKDIR .

ADD ./a.out /a.out

CMD ["/a.out"]

2 Steps to create the image

The a.out is generated by compiling hello.c statically so it does NOT need any user space lib to run.

$ gcc -static hello.c

$ docker build -t mini_image .

Sending build context to Docker daemon  801.3kB

Step 1/4 : FROM scratch

 --->

Step 2/4 : WORKDIR .

 ---> Using cache

 ---> 6ab802804c0d

Step 3/4 : ADD ./a.out /a.out

 ---> Using cache

 ---> 5effc7b72b0e

Step 4/4 : CMD ["/a.out"]

 ---> Using cache

 ---> 4675619c3ed7

Successfully built 4675619c3ed7

Successfully tagged mini_image:latest

3 Run it

$ docker run mini_image

Hello container!