[nexus] Additional test for silo IP pools

[david-crespo]

Followup to #3985. The diff is not very readable, I would just read the result:

omicron/nexus/tests/integration_tests/instances.rs

Lines 3359 to 3452 in 686dfe3

	#[nexus_test]
	async fn test_instance_ephemeral_ip_from_correct_pool(
	cptestctx: &ControlPlaneTestContext,
	) {
	let client = &cptestctx.external_client;
	let _ = create_project(&client, PROJECT_NAME).await;
	// Create two IP pools.
	//
	// The first is given to the "default" pool, the provided to a distinct
	// explicit pool.
	let default_pool_range = IpRange::V4(
	Ipv4Range::new(
	std::net::Ipv4Addr::new(10, 0, 0, 1),
	std::net::Ipv4Addr::new(10, 0, 0, 5),
	)
	.unwrap(),
	);
	let other_pool_range = IpRange::V4(
	Ipv4Range::new(
	std::net::Ipv4Addr::new(10, 1, 0, 1),
	std::net::Ipv4Addr::new(10, 1, 0, 5),
	)
	.unwrap(),
	);
	populate_ip_pool(&client, "default", Some(default_pool_range)).await;
	create_ip_pool(&client, "other-pool", Some(other_pool_range)).await;
	// Create an instance with pool name blank, expect IP from default pool
	create_instance_with_pool(client, "default-pool-inst", None).await;
	let ip = fetch_instance_ephemeral_ip(client, "default-pool-inst").await;
	assert!(
	ip.ip >= default_pool_range.first_address()
	&& ip.ip <= default_pool_range.last_address(),
	"Expected ephemeral IP to come from default pool"
	);
	// Create an instance explicitly using the "other-pool".
	create_instance_with_pool(client, "other-pool-inst", Some("other-pool"))
	.await;
	let ip = fetch_instance_ephemeral_ip(client, "other-pool-inst").await;
	assert!(
	ip.ip >= other_pool_range.first_address()
	&& ip.ip <= other_pool_range.last_address(),
	"Expected ephemeral IP to come from other pool"
	);
	// now create a third pool, a silo default, to confirm it gets used. not
	// using create_ip_pool because we need to specify a silo and default: true
	let pool_name = "silo-pool";
	let _silo_pool: views::IpPool = object_create(
	client,
	"/v1/system/ip-pools",
	&params::IpPoolCreate {
	identity: IdentityMetadataCreateParams {
	name: pool_name.parse().unwrap(),
	description: String::from("an ip pool"),
	},
	silo: Some(NameOrId::Id(DEFAULT_SILO.id())),
	is_default: true,
	},
	)
	.await;
	let silo_pool_range = IpRange::V4(
	Ipv4Range::new(
	std::net::Ipv4Addr::new(10, 2, 0, 1),
	std::net::Ipv4Addr::new(10, 2, 0, 5),
	)
	.unwrap(),
	);
	populate_ip_pool(client, pool_name, Some(silo_pool_range)).await;
	create_instance_with_pool(client, "silo-pool-inst", Some("silo-pool"))
	.await;
	let ip = fetch_instance_ephemeral_ip(client, "silo-pool-inst").await;
	assert!(
	ip.ip >= silo_pool_range.first_address()
	&& ip.ip <= silo_pool_range.last_address(),
	"Expected ephemeral IP to come from the silo default pool"
	);
	// we can still specify other pool even though we now have a silo default
	create_instance_with_pool(client, "other-pool-inst-2", Some("other-pool"))
	.await;
	let ip = fetch_instance_ephemeral_ip(client, "other-pool-inst-2").await;
	assert!(
	ip.ip >= other_pool_range.first_address()
	&& ip.ip <= other_pool_range.last_address(),
	"Expected ephemeral IP to come from the other pool"
	);
	}