I setup both of my mesos-master and mesos-slave on a standalone server. E.g. To start my mesos-slave, I used this command:
sudo bin/mesos-slave.sh --master=zk://<IP address of server>:2181/mesos --log_dir=/var/log/mesos --containerizers=docker,mesos
What I am trying to figure out is how the containerizer on Mesos is implemented with just --containerizers=docker,mesos.
Will it be able to automatically detect whether Docker is installed on the mesos-slave? If it is, which tcp port will it normally get? port 4243 or 2375?
Mesos will try to autodetect docker by running docker version. You can specific an absolute path for the docker executable by passing the --docker=/path/to/docker flag to the slave. There are other docker-specific flags for the slave, like --docker_sandbox_directory, --docker_remove_delay, and --docker_stop_timeout. For more details on those, see https://mesos.apache.org/documentation/latest/configuration/
Mesos currently uses the docker command-line interface locally from the slave node, not via the remote API, so I don't think the docker port is relevant here.