A very small docker container (< 2MB) containing only memcached 1.4.20.
To run with default options:
docker run -d -p 11211:11211 jbogatay/memcached
To specify runtime options
docker run -d -p 11211:11211 jbogatay/memcached -u root [whatever other options you want here]
To view available options
docker run --rm jbogatay/memcached -h