Syncing Hosts’ information

Currently syncing the hosts’ information will update all of the Host datastructures with some specific data about them (e.g network IPs, processor information). This let’s the user code to take decisions based on those information.

Note

The synchronisation is based on Ansible facts gathering and it somehow makes the Ansible facts available to the experimenter’s python code. It comes at the cost of making a connection to every single host (which can be heavy when managing thousands of hosts).

Also, in the future, we expect some providers to fill an initial version of the updated attribute to avoid a full sync. For instance, on Grid’5000 many information can be retrieved from the REST API.

Examples

import logging
from pathlib import Path

import enoslib as en

en.init_logging(level=logging.INFO)
en.check()

job_name = Path(__file__).name

conf = en.G5kConf.from_settings(job_type=[], job_name=job_name).add_machine(
    roles=["control"], cluster="paravance", nodes=1
)

provider = en.G5k(conf)
roles, networks = provider.init()

roles_synced = en.sync_info(roles, networks)

# some info has been populated
h = roles_synced["control"][0]
assert len(h.net_devices) > 0
assert h.processor is not None

# we can filter addresses based on a given network (one ipv4 address here)
assert len(h.filter_addresses(networks["my_network"])) >= 1

# add an ipv6 (if not already there)
en.run_command("dhclient -6 br0", roles=roles)

# resync
roles_synced = en.sync_info(roles, networks)
h = roles_synced["control"][0]

# we now have two addresses in the network my_network (one ipv4, one ipv6)
assert len(h.filter_addresses(networks["my_network"])) == 2