samples

The samples

In this folder some examples and templates are given. What is shown here is actually, what you would need to supply for ansible-cluster to work.

The environment

The first start script already sets the needed environment variables which are listed below

• CLUSTER_ACCOUNTING
• CLUSTER_CONFIG
• CLUSTER_GROUPS
• CLUSTER_PARTITIONS
• CLUSTER_SSH_LIMITS
• CLUSTER_USERS

Those variables should point to your own configurations, which are explained below.

The ansible-cluster inventory

In order to use ansible-cluster some host variables and host groups need to be defined. In cluster_hosts_example some examples are shown. Instead of having all of the variables in a single file, the inventory can be split up into many files. Please take a look at the official 'Ansible documentation' on the inventory.

Examples and Templates

config_template.yml

config_template.yml represents the main configuration file, meaning this is where most of the variables for the ansible-cluster cluster are defined. In config_template.yml all needed and used variables can be seen with example settings.

groups_example.yml

In groups_example.yml all groups for user accounts can be defined, a few examples are shown in groups_example.yml. Those groups can be deployed via

ansible-playbook playbooks/sync_users.yml

Please have a look at usertool which can generate such files.

partition_config_example.yml

In partition_config_example.yml are the partitions of a Slurm cluster defined, have a look at partition_config_example.yml for examples.

slurm_accounts_example.yml

ansible-cluster uses accouting in Slurm to restrict accesses to cluster nodes. For that, some accounts have to be created in Slurm. Examples are shown in slurm_accounts_example.yml and can be added to the Slurm cluster via

ansible-playbook playbooks/slurm_accounting.yml

ssh_access_limits_example.yml

These Ansible variables are used in the common role inside the limit_ssh.yml play. Any cluster node being defined here is automatically restricted to the following

AllowUsers {{ssh_anywhere}} {{ssh_access_limits[ansible_hostname]}}

So this play essentially sets the AllowUsers line in the sshd_config of a system.

users_example.yml

In users_example.yml all user accounts eligible for using the cluster are defined, a few examples analogue to the groups are shown in users_example.yml. Those users can be deployed via

ansible-playbook playbooks/sync_users.yml

and please have a look at usertool which can generate such files.