Automated cluster account provisioning for gateway users

The initial use case for this system is the IU Cybergateway. We need the following capabilities:

• query for whether a user has an account
  • for IU Cybergateway the user cluster access is determined by querying LDAP
• add an SSH public key for the user to authenticate (actually Airavata to authenticate on behalf of the user) to the cluster
  • for IU Cybergateway the key is added to LDAP

Once the user has a cluster account and their SSH key has been added the following additional things need to be done

• test that Airavata can authenticate to the cluster on the users behalf
• add a scratch location that Airavata will use for the user on the cluster

Eric Coulter has developed a prototype LDAP client that can query for a user's account and deposit an SSH key in LDAP: https://github.iu.edu/jecoulte/airavata-ldap-prototype (note: this link is only accessible via IU credentials).