Reconfigurator: Record external networking allocations when realizing…

… a blueprint (#5045)

This PR expands blueprint execution to record external IPs and created
NICs for Nexus, Boundary NTP, and External DNS in crdb _before_ sending
new zone requests to sled-agents.

The implementation has a very obvious TOCTOU race, but I think it's okay
(as explained in the comments inline). If two Nexuses try to realize the
same blueprint simultaneously and both see no records present, only one
will succeed to insert, and the other will spuriously fail. Assuming
that failure causes a retry, subsequent attempts to realize the same
blueprint will succeed, as the required records will be present. If this
seems wrong, please holler!

I'd like to give this a spin on either madrid or one of the software
testbeds before merging, but I think this is ready for review.

nexus/blueprint-execution/src/lib.rs

@@ -21,6 +21,7 @@ use uuid::Uuid;
 
 mod dns;
 mod omicron_zones;
+mod resource_allocation;
 
 struct Sled {
     id: Uuid,
@@ -69,6 +70,14 @@ where
         "blueprint_id" => ?blueprint.id
     );
 
+    resource_allocation::ensure_zone_resources_allocated(
+        &opctx,
+        datastore,
+        &blueprint.omicron_zones,
+    )
+    .await
+    .map_err(|err| vec![err])?;
+
     let sleds_by_id: BTreeMap<Uuid, _> = datastore
         .sled_list_all_batched(&opctx)
         .await
@@ -82,9 +91,9 @@ where
 
     dns::deploy_dns(
         &opctx,
-        &datastore,
+        datastore,
         String::from(nexus_label),
-        &blueprint,
+        blueprint,
         &sleds_by_id,
     )
     .await