Kademlia

This is a Kademlia implementation written in the course D7024E at LTU in fall 2020.

Installation of Docker packages

Install Docker packages (exact command may be environment dependent).

apt-get install docker.io apt-get install docker-compose

Note: You may need to use sudo during installation or use.

Docker swarm

Specify desired number of replicated containers in Dockerfile in line for replicas

deploy:
  mode: replicated
  replicas: 50

./build.sh
cd docker
docker build . -t kadlab
docker swarm init
docker stack deploy --compose-file docker-compose.yml kadstack

Here you must wait for the containers to spin up. You can check that it is all done by running docker ps | wc and see that the amount of lines is n + 1.

./bootstrap.sh

Say you want to log in to a specific node, e.g., 2cdaa139

docker exec -it 2cdaa139 /bin/sh
tmux attach

Connection test

To test communication between containers, We first find the container id by listing all active containers:

docker ps

To determine the overlay network kademlia_network address of a container, inspect the container and look for NetworkSettings.Networks.kademlia_kademlia_network.IPAddress:

docker inspect <CONTAINER_ID>
(IP is given directly with: --format='{{<DATA PATH>}}')

We the container ID to execute a shell on the container

docker exec -it <CONTAINER_ID> /bin/sh

From there, we can ping another container

ping <IP_ADDR>

We can also use the ping2host.sh script to see that any node can ping any other node.

./ping2host.sh

Notes for usage:

• ^P^Q to deattach
• Tear down stack (crudely, hints that the containers should be nicely terminated): docker stack rm kadstack
• Inspect networks docker network <ls / inspect <NETWORK_ID>>

References:

• Docker documentation and man-pages.