Unit tests for dnsmasq lease state propagation

[lukasjuhrich]

dnsmasq's internal knowledge about the leases is hidden in memory.

For that reason, we use a --dhcp-script to persistently mirror this state in the auth_dhcp_leases table (also for unauth).
Furthermore, dnsmasq bootstraps this state by passing said script the init command.

To ensure correctness of this synchronization, we should add unit tests for the lease_server.

Mainly, this means extending test stubs like the following:

hades/tests/test_lease_sync.py

Lines 69 to 70 in d8a48d4

	def test_add_lease():
	pass

The lease server is not completely untested, however: Some bats tests check whether the lease invalidation on refresh works correctly, which at least uses

• the capability of dnsmasq to correctly reconstruct the lease state using the init command
• the capability of the lease server to accept the delete command and delete the corresponding row in the leases table

[lukasjuhrich]

A low-hanging fruit would be to extend the existing {un,}auth-dhcp integration tests to check that e.g. a successful lease makes its way to the auth-dhcp-lease table, like for instance in here:

hades/tests/test-auth-dhcp.bats

Lines 58 to 87 in d8a48d4

	@test "check that client can acquire DHCP lease" {
	run ns dhcpcd \
	--config /dev/null \
	--script "$dhcpcd_script" \
	--env script_output_dir="$script_output_dir" \
	--env variable=env \
	--option domain_name_servers,domain_name,domain_search,host_name \
	--timeout 10 \
	--noipv4ll \
	--ipv4only \
	--oneshot eth0 \
	;
	echo "$output" >&2
	[[ $status = 0 ]]
	[[ -f "${script_output_dir}/BOUND" ]]
	source "${script_output_dir}/BOUND"
	declare -p env
	[[ "${env[new_broadcast_address]}" = "$(netaddr.broadcast "$gateway_ip_address")" ]]
	[[ "${env[new_dhcp_lease_time]}" = "86400" ]]
	[[ "${env[new_dhcp_rebinding_time]}" = "75600" ]]
	[[ "${env[new_dhcp_renewal_time]}" = "43200" ]]
	[[ "${env[new_dhcp_server_identifier]}" = "$(netaddr.ip "$auth_ip")" ]]
	[[ "${env[new_domain_name]}" = users.agdsn.de ]]
	[[ "${env[new_domain_name_servers]}" = "$(netaddr.ip "$auth_ip")" ]]
	[[ "${env[new_ip_address]}" = "$(netaddr.ip "$client_ip_address")" ]]
	[[ "${env[new_network_number]}" = "$(netaddr.network "$gateway_ip_address")" ]]
	[[ "${env[new_routers]}" = "$(netaddr.ip "$gateway_ip_address")" ]]
	[[ "${env[new_subnet_cidr]}" = "$(netaddr.prefixlen "$gateway_ip_address")" ]]
	[[ "${env[new_subnet_mask]}" = "$(netaddr.netmask "$gateway_ip_address")" ]]
	}