What's that?

Recursive Fibonacci with Docker inside Docker inside Docker inside...

Why so much hate?

I wanted to learn more about Docker before I deploy apps with Docker. And it's fun!

Build

docker build -t dgageot/fiboid .

Run

docker run --rm --privileged -ti -v /var/lib/docker:/var/lib/docker dgageot/fiboid 0
docker run --rm --privileged -ti -v /var/lib/docker:/var/lib/docker dgageot/fiboid 1
docker run --rm --privileged -ti -v /var/lib/docker:/var/lib/docker dgageot/fiboid 2
docker run --rm --privileged -ti -v /var/lib/docker:/var/lib/docker dgageot/fiboid 4

How it works

Here's the algorithm:

if value is 0 then return 0
if value is 1 then return 1
otherwise
start a docker daemon inside current docker container
run a container for value-2
run a container for value-1
return the sum of the two values

Most of the time is spent starting docker -d and sleeping until it's started.

Sample Execution Plan

docker run --rm --privileged -ti -v /var/lib/docker:/var/lib/docker dgageot/fiboid 7
- docker 7 (=13)
  - docker 5
    - docker 3
      - docker 1
      - docker 2
        - docker 0
        - docker 1
    - docker 4
      - docker 2
        - docker 0
        - docker 1
      - docker 3
        - docker 1
        - docker 2
          - docker 0
          - docker 1 (depth=6)
  - docker 6
    - docker 4
      - docker 2
        - docker 0
        - docker 1
      - docker 3
        - docker 1
        - docker 2
          - docker 0
          - docker 1
    - docker 5
      - docker 3
        - docker 1
        - docker 2
          - docker 0
          - docker 1
      - docker 4
        - docker 2
          - docker 0
          - docker 1
        - docker 3
          - docker 1
          - docker 2
            - docker 0
            - docker 1