fix_snmp overwrote snmpd.conf with an application's values (community
"public", "Managed by netOrk", netork@localhost) through a fixed
/tmp/netork_snmpd.conf, and opened ufw for a /24 guessed from ss;
install_lldpd was an action of its own. Neither read an exit status.
The driver implements napalm-device-types 4.13's templates instead:
- configure_snmp_agent(settings): net-snmp installed, snmpd.conf with
one rocommunity line per allowed source (mktemp, install as root),
ufw opened for those sources only (pve-firewall stays the
operator's), snmpd enabled and restarted;
- get_management_peer() from SSH_CONNECTION;
- install_package(name), as the contract says (raises when apt fails),
so ensure_package comes from the base package.
Every step reads its exit status.
BREAKING CHANGE: run_device_action is removed. Requires
napalm-device-types 4.13.
Part of #24.
