The pcluster ssh is a wrapper around SSH. Depending on the case, you can also log in to your head node using ssh and the public or private IP address.
You can list existing clusters using the following command. This is a convenient way to find the name of a cluster in case you forget it.
pcluster list --color -r $AWS_REGION
Now that your cluster has been created, log in to the head node using the following command in your AWS Cloud9 terminal:
pcluster ssh hpc-cluster-lab -i ~/.ssh/$SSH_KEY_NAME -r $AWS_REGION
The EC2 instance asks for confirmation of the ssh login the first time you log in to the instance. Type yes.
Now that you are connected to the head node, familiarize yourself with the cluster structure by running the following set of commands.
Lmod is a fairly standard tool used to dynamically change your environment.
module load intelmpi which mpirun
showmount -e localhost
Next, you can run your first job!