[nexus] Add schema changes for quiescing

nexus/db-model/src/db_metadata.rs

@@ -7,29 +7,95 @@ use chrono::{DateTime, Utc};
 use nexus_db_schema::schema::db_metadata;
 use serde::{Deserialize, Serialize};
 
-/// Internal database metadata
+/// These fields of "db_metadata" have been stable since the initial
+/// release of the database.
+///
+/// For backwards-compatibility purposes, they can be loaded separately
+/// from DbMetadata.
 #[derive(
     Queryable, Insertable, Debug, Clone, Selectable, Serialize, Deserialize,
 )]
 #[diesel(table_name = db_metadata)]
-pub struct DbMetadata {
+pub struct DbMetadataBase {
     singleton: bool,
     time_created: DateTime<Utc>,
     time_modified: DateTime<Utc>,
     version: SemverVersion,
     target_version: Option<SemverVersion>,
 }
 
+impl DbMetadataBase {
+    pub fn version(&self) -> &SemverVersion {
+        &self.version
+    }
+}
+
+/// Internal database metadata
+#[derive(
+    Queryable, Insertable, Debug, Clone, Selectable, Serialize, Deserialize,
+)]
+#[diesel(table_name = db_metadata)]
+pub struct DbMetadata {
+    #[diesel(embed)]
+    base: DbMetadataBase,
+    quiesce_started: bool,
+    quiesce_completed: bool,
+}
+
 impl DbMetadata {
+    pub fn from_base(base: DbMetadataBase, quiesced: bool) -> Self {
+        Self { base, quiesce_started: quiesced, quiesce_completed: quiesced }
+    }
+
     pub fn time_created(&self) -> &DateTime<Utc> {
-        &self.time_created
+        &self.base.time_created
     }
 
     pub fn time_modified(&self) -> &DateTime<Utc> {
-        &self.time_modified
+        &self.base.time_modified
     }
 
     pub fn version(&self) -> &SemverVersion {
-        &self.version
+        &self.base.version
+    }
+
+    pub fn target_version(&self) -> Option<&SemverVersion> {
+        self.base.target_version.as_ref()
+    }
+
+    pub fn quiesce_started(&self) -> bool {
+        self.quiesce_started
+    }
+
+    pub fn quiesce_completed(&self) -> bool {
+        self.quiesce_completed
+    }
+}
+
+#[derive(AsChangeset)]
+#[diesel(table_name = db_metadata)]
+pub struct DbMetadataUpdate {
+    time_modified: DateTime<Utc>,
+    version: String,
+    #[diesel(treat_none_as_null = true)]
+    target_version: Option<String>,
+    quiesce_started: Option<bool>,
+    quiesce_completed: Option<bool>,
+}
+
+impl DbMetadataUpdate {
+    pub fn update_to_version(version: semver::Version) -> Self {
+        Self {
+            time_modified: Utc::now(),
+            version: version.to_string(),
+            target_version: None,
+            quiesce_started: None,
+            quiesce_completed: None,
+        }
+    }
+
+    pub fn clear_quiesce(&mut self) {
+        self.quiesce_started = Some(false);
+        self.quiesce_completed = Some(false);
     }
 }

nexus/db-model/src/schema_versions.rs

@@ -16,7 +16,7 @@ use std::{collections::BTreeMap, sync::LazyLock};
 ///
 /// 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: Version = Version::new(174, 0, 0);
+pub const SCHEMA_VERSION: Version = Version::new(175, 0, 0);
 
 /// List of all past database schema versions, in *reverse* order
 ///
@@ -28,6 +28,7 @@ static KNOWN_VERSIONS: LazyLock<Vec<KnownVersion>> = LazyLock::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(175, "db-metadata-quiesce"),
         KnownVersion::new(174, "add-tuf-rot-by-sign"),
         KnownVersion::new(173, "inv-internal-dns"),
         KnownVersion::new(172, "add-zones-with-mupdate-override"),
@@ -218,6 +219,13 @@ static KNOWN_VERSIONS: LazyLock<Vec<KnownVersion>> = LazyLock::new(|| {
 /// The earliest supported schema version.
 pub const EARLIEST_SUPPORTED_VERSION: Version = Version::new(1, 0, 0);
 
+/// The version of the schema where "quiesce" fields were added
+/// to db_metadata.
+///
+/// omicron.public.db_metadata is read a part of performing schema changes,
+/// so this version is treated specially for backwards compatibiliy.
+pub const QUIESCE_VERSION: Version = Version::new(175, 0, 0);
+
 /// Describes one version of the database schema
 #[derive(Debug, Clone)]
 struct KnownVersion {