fix: Return UUID when a database is deleted

So that it can be immediately used to restore elsewhere.

Cargo.lock

@@ -1685,6 +1685,7 @@ dependencies = [
  "thiserror",
  "tokio",
  "tonic",
+ "uuid",
 ]
 
 [[package]]

generated_types/protos/influxdata/iox/management/v1/service.proto

@@ -174,7 +174,9 @@ message DeleteDatabaseRequest {
   string db_name = 1;
 }
 
-message DeleteDatabaseResponse {}
+message DeleteDatabaseResponse {
+  bytes uuid = 1;
+}
 
 message RestoreDatabaseRequest {
   // Was the generation ID of the deleted database.

influxdb_iox/src/commands/database.rs

@@ -342,8 +342,9 @@ pub async fn command(connection: Connection, config: Config) -> Result<()> {
         }
         Command::Delete(command) => {
             let mut client = management::Client::new(connection);
-            client.delete_database(&command.name).await?;
-            println!("Deleted database {}", command.name);
+            let uuid = client.delete_database(&command.name).await?;
+            eprintln!("Deleted database {}", command.name);
+            println!("{}", uuid);
         }
         Command::Restore(command) => {
             let mut client = management::Client::new(connection);

influxdb_iox/src/influxdb_ioxd/rpc/error.rs

@@ -130,12 +130,9 @@ pub fn default_database_error_handler(error: server::database::Error) -> tonic::
             error!(%source, "Unexpected error deleting database");
             InternalError {}.into()
         }
-        Error::NoActiveDatabaseToDelete { db_name } => NotFound {
-            resource_type: "database".to_string(),
-            resource_name: db_name,
-            ..Default::default()
+        Error::CannotDeleteInactiveDatabase { .. } => {
+            tonic::Status::failed_precondition(error.to_string())
         }
-        .into(),
         Error::CannotRestoreActiveDatabase { .. } => {
             tonic::Status::failed_precondition(error.to_string())
         }

influxdb_iox/src/influxdb_ioxd/server_type/database/rpc/management.rs

@@ -175,12 +175,15 @@ where
     ) -> Result<Response<DeleteDatabaseResponse>, Status> {
         let db_name = DatabaseName::new(request.into_inner().db_name).field("db_name")?;
 
-        self.server
+        let uuid = self
+            .server
             .delete_database(&db_name)
             .await
             .map_err(default_server_error_handler)?;
 
-        Ok(Response::new(DeleteDatabaseResponse {}))
+        Ok(Response::new(DeleteDatabaseResponse {
+            uuid: uuid.as_bytes().to_vec(),
+        }))
     }
 
     async fn restore_database(

influxdb_iox/tests/end_to_end_cases/deletes.rs

@@ -18,8 +18,7 @@ async fn test_querying_deleted_database() {
         ..Default::default()
     };
 
-    // Add some data to the first generation of the database and
-    // ensure the data is returned.
+    // Add some data to the database and ensure the data is returned.
 
     management_client
         .create_database(rules.clone())

influxdb_iox/tests/end_to_end_cases/management_cli.rs

@@ -244,17 +244,24 @@ async fn delete_database() {
         .success()
         .stdout(active_db_match(db, 0));
 
-    // Delete the database
-    Command::cargo_bin("influxdb_iox")
-        .unwrap()
-        .arg("database")
-        .arg("delete")
-        .arg(db)
-        .arg("--host")
-        .arg(addr)
-        .assert()
-        .success()
-        .stdout(predicate::str::contains(format!("Deleted database {}", db)));
+    // Delete the database, returns the UUID
+    let db_uuid = String::from_utf8(
+        Command::cargo_bin("influxdb_iox")
+            .unwrap()
+            .arg("database")
+            .arg("delete")
+            .arg(db)
+            .arg("--host")
+            .arg(addr)
+            .assert()
+            .success()
+            .stderr(predicate::str::contains(format!("Deleted database {}", db)))
+            .get_output()
+            .stdout
+            .clone(),
+    )
+    .unwrap();
+    let db_uuid = db_uuid.trim();
 
     // Listing the databases does not include the deleted database
     Command::cargo_bin("influxdb_iox")
@@ -316,19 +323,7 @@ async fn delete_database() {
         .success()
         .stdout(predicate::str::contains(db));
 
-    // Listing detailed database info includes both active and deleted
-    Command::cargo_bin("influxdb_iox")
-        .unwrap()
-        .arg("database")
-        .arg("list")
-        .arg("--detailed")
-        .arg("--host")
-        .arg(addr)
-        .assert()
-        .success()
-        .stdout(deleted_db_match(db, 0).and(active_db_match(db, 1)));
-
-    // Delete the 2nd database
+    // Delete the 2nd database, returns its UUID
     Command::cargo_bin("influxdb_iox")
         .unwrap()
         .arg("database")
@@ -338,7 +333,7 @@ async fn delete_database() {
         .arg(addr)
         .assert()
         .success()
-        .stdout(predicate::str::contains(format!("Deleted database {}", db)));
+        .stderr(predicate::str::contains(format!("Deleted database {}", db)));
 
     // This database should no longer be in the active list
     Command::cargo_bin("influxdb_iox")

influxdb_iox_client/Cargo.toml

@@ -25,6 +25,7 @@ serde = "1.0.128"
 serde_json = { version = "1.0.67", optional = true }
 thiserror = "1.0.30"
 tonic = { version = "0.5.0" }
+uuid = { version = "0.8", features = ["v4"] }
 
 [dev-dependencies] # In alphabetical order
 serde_json = "1.0"

influxdb_iox_client/src/client/management.rs

@@ -1,13 +1,12 @@
-use bytes::Bytes;
-use thiserror::Error;
-
 use self::generated_types::{management_service_client::ManagementServiceClient, *};
-
-use crate::connection::Connection;
-
-use crate::google::{longrunning::IoxOperation, FieldViolation};
-use std::convert::TryInto;
-use std::num::NonZeroU32;
+use crate::{
+    connection::Connection,
+    google::{longrunning::IoxOperation, FieldViolation},
+};
+use bytes::Bytes;
+use std::{convert::TryInto, num::NonZeroU32};
+use thiserror::Error;
+use uuid::Uuid;
 
 /// Re-export generated_types
 pub mod generated_types {
@@ -144,6 +143,10 @@ pub enum DeleteDatabaseError {
     /// Client received an unexpected error from the server
     #[error("Unexpected server error: {}: {}", .0.code(), .0.message())]
     ServerError(tonic::Status),
+
+    /// UUID returned as bytes from server could not be converted to a `Uuid`
+    #[error("Invalid UUID: {}: {:?}", .0, .0)]
+    InvalidUuid(uuid::Error),
 }
 
 /// Errors returned by Client::delete_database
@@ -656,8 +659,9 @@ impl Client {
     pub async fn delete_database(
         &mut self,
         db_name: impl Into<String> + Send,
-    ) -> Result<(), DeleteDatabaseError> {
-        self.inner
+    ) -> Result<Uuid, DeleteDatabaseError> {
+        let response = self
+            .inner
             .delete_database(DeleteDatabaseRequest {
                 db_name: db_name.into(),
             })
@@ -669,7 +673,10 @@ impl Client {
                 _ => DeleteDatabaseError::ServerError(status),
             })?;
 
-        Ok(())
+        let uuid = Uuid::from_slice(&response.into_inner().uuid)
+            .map_err(DeleteDatabaseError::InvalidUuid)?;
+
+        Ok(uuid)
     }
 
     /// Restore database

server/src/database.rs

@@ -82,14 +82,17 @@ pub enum Error {
     #[snafu(display("cannot persisted updated rules: {}", source))]
     CannotPersistUpdatedRules { source: crate::rules::Error },
 
-    #[snafu(display("cannot mark database deleted: {}", source))]
+    #[snafu(display("cannot mark database {} deleted: {}", db_name, source))]
     CannotMarkDatabaseDeleted {
         db_name: String,
         source: object_store::Error,
     },
 
-    #[snafu(display("no active database named {} to delete", db_name))]
-    NoActiveDatabaseToDelete { db_name: String },
+    #[snafu(display(
+        "cannot delete database named {} that has already been marked as deleted",
+        db_name
+    ))]
+    CannotDeleteInactiveDatabase { db_name: String },
 
     #[snafu(display("cannot restore database named {} that is already active", db_name))]
     CannotRestoreActiveDatabase { db_name: String },
@@ -239,7 +242,7 @@ impl Database {
     }
 
     /// Mark this database as deleted.
-    pub async fn delete(&self) -> Result<(), Error> {
+    pub async fn delete(&self) -> Result<Uuid, Error> {
         let db_name = &self.shared.config.name;
         info!(%db_name, "marking database deleted");
 
@@ -249,7 +252,7 @@ impl Database {
         {
             let state = self.shared.state.read();
             // Can't delete an already deleted database.
-            ensure!(state.is_active(), NoActiveDatabaseToDelete { db_name });
+            ensure!(state.is_active(), CannotDeleteInactiveDatabase { db_name });
         }
 
         // If there is an object store for this database, write out a tombstone file.
@@ -259,7 +262,7 @@ impl Database {
             .with_context(|| {
                 let state = self.shared.state.read();
                 TransitionInProgress {
-                    db_name,
+                    db_name: db_name.clone(),
                     state: state.state_code(),
                 }
             })?
@@ -267,6 +270,8 @@ impl Database {
             .await
             .context(CannotMarkDatabaseDeleted { db_name })?;
 
+        let uuid = self.provided_rules().expect("should have rules").uuid();
+
         let mut state = self.shared.state.write();
         let mut state = state.unfreeze(handle);
         *state = DatabaseState::NoActiveDatabase(
@@ -275,7 +280,7 @@ impl Database {
         );
         self.shared.state_notify.notify_waiters();
 
-        Ok(())
+        Ok(uuid)
     }
 
     /// Create a restored database without any any state.

server/src/lib.rs

@@ -736,10 +736,31 @@ where
 
     /// Delete an existing, active database with this name. Return an error if no active database
     /// with this name can be found.
-    pub async fn delete_database(&self, db_name: &DatabaseName<'static>) -> Result<()> {
+    pub async fn delete_database(&self, db_name: &DatabaseName<'static>) -> Result<Uuid> {
+        // Wait for exclusive access to mutate server state
+        let handle_fut = self.shared.state.read().freeze();
+        let handle = handle_fut.await;
+
         let database = self.database(db_name)?;
-        database.delete().await.context(CannotMarkDatabaseDeleted)?;
-        Ok(())
+        let uuid = database.delete().await.context(CannotMarkDatabaseDeleted)?;
+
+        {
+            let mut state = self.shared.state.write();
+
+            // Exchange FreezeHandle for mutable access via WriteGuard
+            let mut state = state.unfreeze(handle);
+
+            match &mut *state {
+                ServerState::Initialized(initialized) => {
+                    initialized.databases.remove(db_name);
+                }
+                _ => unreachable!(),
+            }
+        }
+
+        self.persist_server_config().await?;
+
+        Ok(uuid)
     }
 
     /// Restore a database and generation that has been marked as deleted. Return an error if no