Add timeseries schema to CockroachDB on Nexus startup

- Adds tables representing the timeseries schema. These currently track
  the core data about a schema that is fixed across versions; the set of
  fields, also across all versions; and then the mapping between the
  schema and their fields in each particular version.
- Add database models for these
- Add a build.rs to `oximeter` which sets up a const fn that returns all
  schema known at compile-time. Nexus uses this to determine which
  schema need to be loaded during population time.
- Add datastore methods for loading all those schema during population,
  and adds a populator using it.
- Adds more datatstore methods for fetching, listing, and upserting
  timeseries schema. There are a number of tests around these, but they
  are currently unused outside the datastore crate itself (other than
  the populator). The existing Nexus methods for those operations go
  through ClickHouse directly now, but they'll eventually be redirected
  to CockroachDB when the remainder of the switch is completed.

nexus/db-model/Cargo.toml

@@ -41,14 +41,15 @@ tokio.workspace = true
 uuid.workspace = true
 
 db-macros.workspace = true
-omicron-certificates.workspace = true
-omicron-common.workspace = true
 nexus-config.workspace = true
 nexus-defaults.workspace = true
 nexus-types.workspace = true
+omicron-certificates.workspace = true
+omicron-common.workspace = true
 omicron-passwords.workspace = true
-sled-agent-client.workspace = true
 omicron-workspace-hack.workspace = true
+oximeter.workspace = true
+sled-agent-client.workspace = true
 
 [dev-dependencies]
 camino-tempfile.workspace = true

nexus/db-model/src/lib.rs

@@ -92,6 +92,7 @@ mod sled_underlay_subnet_allocation;
 mod snapshot;
 mod ssh_key;
 mod switch;
+mod timeseries_schema;
 mod tuf_repo;
 mod typed_uuid;
 mod unsigned;
@@ -195,6 +196,7 @@ pub use ssh_key::*;
 pub use switch::*;
 pub use switch_interface::*;
 pub use switch_port::*;
+pub use timeseries_schema::*;
 pub use tuf_repo::*;
 pub use typed_uuid::to_db_typed_uuid;
 pub use upstairs_repair::*;

nexus/db-model/src/schema.rs

@@ -1751,16 +1751,6 @@ table! {
     }
 }
 
-table! {
-    db_metadata (singleton) {
-        singleton -> Bool,
-        time_created -> Timestamptz,
-        time_modified -> Timestamptz,
-        version -> Text,
-        target_version -> Nullable<Text>,
-    }
-}
-
 table! {
     migration (id) {
         id -> Uuid,
@@ -1778,6 +1768,52 @@ table! {
     }
 }
 
+table! {
+    timeseries_schema (timeseries_name) {
+        timeseries_name -> Text,
+        authz_scope -> crate::TimeseriesAuthzScopeEnum,
+        target_description -> Text,
+        metric_description -> Text,
+        datum_type -> crate::TimeseriesDatumTypeEnum,
+        units -> crate::TimeseriesUnitsEnum,
+        time_created -> Timestamptz,
+        time_modified -> Timestamptz,
+        generation -> Int8,
+    }
+}
+
+table! {
+    timeseries_field (timeseries_name, name) {
+        timeseries_name -> Text,
+        name -> Text,
+        type_ -> crate::TimeseriesFieldTypeEnum,
+        source -> crate::TimeseriesFieldSourceEnum,
+        description -> Text,
+        time_created -> Timestamptz,
+        time_modified -> Timestamptz,
+        generation -> Int8,
+    }
+}
+
+table! {
+    timeseries_field_by_version (timeseries_name, version, field_name) {
+        timeseries_name -> Text,
+        version -> Int2,
+        field_name -> Text,
+        generation -> Int8,
+    }
+}
+
+table! {
+    db_metadata (singleton) {
+        singleton -> Bool,
+        time_created -> Timestamptz,
+        time_modified -> Timestamptz,
+        version -> Text,
+        target_version -> Nullable<Text>,
+    }
+}
+
 allow_tables_to_appear_in_same_query!(instance, migration);
 allow_tables_to_appear_in_same_query!(migration, vmm);
 joinable!(instance -> migration (migration_id));
@@ -1869,3 +1905,9 @@ joinable!(instance_ssh_key -> instance (instance_id));
 allow_tables_to_appear_in_same_query!(sled, sled_instance);
 
 joinable!(network_interface -> probe (parent_id));
+
+allow_tables_to_appear_in_same_query!(
+    timeseries_field,
+    timeseries_schema,
+    timeseries_field_by_version
+);

nexus/db-model/src/schema_versions.rs

@@ -17,7 +17,7 @@ use std::collections::BTreeMap;
 ///
 /// This must be updated when you change the database schema.  Refer to
 /// schema/crdb/README.adoc in the root of this repository for details.
-pub const SCHEMA_VERSION: SemverVersion = SemverVersion::new(81, 0, 0);
+pub const SCHEMA_VERSION: SemverVersion = SemverVersion::new(82, 0, 0);
 
 /// List of all past database schema versions, in *reverse* order
 ///
@@ -29,6 +29,7 @@ static KNOWN_VERSIONS: Lazy<Vec<KnownVersion>> = Lazy::new(|| {
         // |  leaving the first copy as an example for the next person.
         // v
         // KnownVersion::new(next_int, "unique-dirname-with-the-sql-files"),
+        KnownVersion::new(82, "add-timeseries-schema-tables"),
         KnownVersion::new(81, "add-nullable-filesystem-pool"),
         KnownVersion::new(80, "add-instance-id-to-migrations"),
         KnownVersion::new(79, "nic-spoof-allow"),