Running the following command fails:
sudo docker run -p unix:///tmp/file.sock:44444 -d image_name
Is something wrong with my port forwardin
The accepted answer is partially correct however since you can only link directories, which means you need to link the directory of the socket instead of the socket itself.
The following did it for me when I wanted to connect a postgres socket.
docker run -p 5432:5432 -v /run/postgresql:/run/postgresql -d --name postgres postgres
What this does is link the postgres socket file to your host system.