Add ssh key creation to entrypoint (#6)

* Add ssh key creation to entrypoint

This makes ssh keys available when the container is started
and doesn't require keys to be store in a repo or registry.

* Update documentation to remove obsolete SSH key information

.github/workflows/docker.yml

@@ -41,12 +41,9 @@ jobs:
       -
         name: Test ssh access to Slurm compute nodes
         run: |
-          docker exec slurm-frontend ssh-keygen -t rsa -f /home/admin/.ssh/id_rsa -N ""
-          docker exec slurm-frontend cp /home/admin/.ssh/id_rsa.pub /home/admin/.ssh/authorized_keys
           docker exec slurm-frontend timeout 1s ssh slurmnode1 hostname
-          docker exec slurm-frontend rm -f ~/.ssh/id_rsa
-          docker exec slurm-frontend rm -f ~/.ssh/id_rsa.pub
-          docker exec slurm-frontend rm -f ~/.ssh/authorized_keys
+          docker exec slurm-frontend timeout 1s ssh slurmnode2 hostname
+          docker exec slurm-frontend timeout 1s ssh slurmnode3 hostname
 
       -
         name: Shut down Slurm cluster containers

README.md

@@ -49,29 +49,3 @@ To run a Slurm job:
 ```
 docker exec slurm-frontend srun hostname
 ```
-
-# SSH between Slurm cluster nodes
-
-In some instances it may be useful to have the ability
-to ssh to a given Slurm cluster node. Each container
-runs an ssh service to provide this capability. If
-passwordless ssh access to Slurm nodes is required,
-**NEW** ssh keys will need to be generated after the
-cluster is started. For example:
-```
-docker exec -it slurm-frontend ssh-keygen -t rsa -f /home/admin/.ssh/id_rsa -N ""
-docker exec -it slurm-frontend cp /home/admin/.ssh/id_rsa.pub /home/admin/.ssh/authorized_keys
-```
-This will allow you to (for example) ssh from the
-frontend node to the compute nodes:
-```
-admin@slurmfrontend:~$ ssh slurmnode1
-admin@slurmnode1:~$
-```
-
-## WARNING
-
-***ALWAYS GENERATE NEW KEYS AS SHOWN ABOVE*** every
-time a cluster is started. And **NEVER**, under any
-circumstances whatsoever, reuse ssh keys from
-previous cluster instances or from any other source.

frontend/docker-entrypoint.sh

@@ -6,4 +6,7 @@ sudo sed -i "s/REPLACE_IT/CPUs=${SLURM_CPUS_ON_NODE}/g" /etc/slurm-llnl/slurm.co
 sudo service munge start
 sudo service ssh start
 
+ssh-keygen -t rsa -f /home/admin/.ssh/id_rsa -N ""
+cp /home/admin/.ssh/id_rsa.pub /home/admin/.ssh/authorized_keys
+
 tail -f /dev/null