add Dockerfile & docker-compose.yml

[desaster]

In preparation to archiving the repository, I'm adding a Dockerfile and docker-compose.yml. This should let the software to run even with the very ancient dependencies it has.

The Dockerfile should setup a fully working environment for kippo, including optional dependencies (mysql, xmpp).

All data and configuration should be kept outside the container by using volumes. The docker-compose.yml has these volumes pointing to the usual directories in the main kippo directory.

This is based on the dockerfile by @aristofanischionis in #241 , but I ended up heavily editing it to use alpine and support docker-compose.

usage with docker

To build:

docker build -t kippo:latest .

To use:

cp kippo.cfg.dist kippo.cfg
# (and customize kippo.cfg)

docker run \
    -it \
    --rm \
    --name=kippo \
    -p 2222:2222 \
    -v $(pwd)/log:/app/log \
    -v $(pwd)/dl:/app/dl \
    -v $(pwd)/data:/app/data \
    -v $(pwd)/kippo.cfg:/app/kippo.cfg \
    kippo

usage with docker-compose

With the docker-compose.yml, kippo can be run with a single command:

docker-compose up

To start with the optional mariadb service:

docker-compose --profile with-db up

Additional notes

This doesn't seem to work too well with podman. I think it doesn't support profiles in docker-compose.yml, or the volumes pointing to a file (kippo.cfg).