feat: [UIE-9384] - Add Connection Pool types/endpoints/queries (#13148)

## Description 📝

Add Connection Pool types, endpoints, queries, validation for the upcoming PG Bouncer work

## How to test 🧪

### Verification steps

(How to verify changes)

- [ ] Nothing to test in the UI yet, so we just need to make sure the types match the API spec and that the logic looks good

Author: hana-akamai

packages/api-v4/.changeset/pr-13148-upcoming-features-1764600387228.md

@@ -0,0 +1,5 @@
+---
+"@linode/api-v4": Upcoming Features
+---
+
+Added Database Connection Pool types and endpoints ([#13148](https://github.com/linode/manager/pull/13148))

packages/api-v4/src/databases/databases.ts

@@ -1,5 +1,7 @@
 import {
+  createDatabaseConnectionPoolSchema,
   createDatabaseSchema,
+  updateDatabaseConnectionPoolSchema,
   updateDatabaseSchema,
 } from '@linode/validation/lib/databases.schema';
 
@@ -14,6 +16,7 @@ import Request, {
 
 import type { Filter, ResourcePage as Page, Params } from '../types';
 import type {
+  ConnectionPool,
   CreateDatabasePayload,
   Database,
   DatabaseBackup,
@@ -364,3 +367,73 @@ export const getDatabaseEngineConfig = (engine: Engine) =>
     setURL(`${API_ROOT}/databases/${encodeURIComponent(engine)}/config`),
     setMethod('GET'),
   );
+
+/**
+ * Get a paginated list of connection pools for a database
+ */
+export const getDatabaseConnectionPools = (databaseID: number) =>
+  Request<Page<ConnectionPool>>(
+    setURL(
+      `${API_ROOT}/databases/postgresql/instances/${encodeURIComponent(databaseID)}/connection-pools`,
+    ),
+    setMethod('GET'),
+  );
+
+/**
+ * Get a connection pool for a database
+ */
+export const getDatabaseConnectionPool = (
+  databaseID: number,
+  poolName: string,
+) =>
+  Request<ConnectionPool>(
+    setURL(
+      `${API_ROOT}/databases/postgresql/instances/${encodeURIComponent(databaseID)}/connection-pools/${encodeURIComponent(poolName)}`,
+    ),
+    setMethod('GET'),
+  );
+
+/**
+ * Create a new connection pool for a database. Connection pools can only be created on active clusters
+ */
+export const createDatabaseConnectionPool = (
+  databaseID: number,
+  data: ConnectionPool,
+) =>
+  Request<ConnectionPool>(
+    setURL(
+      `${API_ROOT}/databases/postgresql/instances/${encodeURIComponent(databaseID)}/connection-pools`,
+    ),
+    setMethod('POST'),
+    setData(data, createDatabaseConnectionPoolSchema),
+  );
+
+/**
+ * Update an existing connection pool. This may cause sudden closure of an in-use connection pool
+ */
+export const updateDatabaseConnectionPool = (
+  databaseID: number,
+  poolName: string,
+  data: Omit<ConnectionPool, 'label'>,
+) =>
+  Request<ConnectionPool>(
+    setURL(
+      `${API_ROOT}/databases/postgresql/instances/${encodeURIComponent(databaseID)}/connection-pools/${encodeURIComponent(poolName)}`,
+    ),
+    setMethod('PUT'),
+    setData(data, updateDatabaseConnectionPoolSchema),
+  );
+
+/**
+ * Delete an existing connection pool. This may cause sudden closure of an in-use connection pool
+ */
+export const deleteDatabaseConnectionPool = (
+  databaseID: number,
+  poolName: string,
+) =>
+  Request<{}>(
+    setURL(
+      `${API_ROOT}/databases/postgresql/instances/${encodeURIComponent(databaseID)}/connection-pools/${encodeURIComponent(poolName)}`,
+    ),
+    setMethod('DELETE'),
+  );

packages/api-v4/src/databases/types.ts

@@ -105,6 +105,7 @@ type MemberType = 'failover' | 'primary';
 export interface DatabaseInstance {
   allow_list: string[];
   cluster_size: ClusterSize;
+  connection_pool_port: null | number;
   connection_strings: ConnectionStrings[];
   created: string;
   /** @Deprecated used by rdbms-legacy only, rdbms-default always encrypts */
@@ -249,3 +250,13 @@ export interface UpdateDatabasePayload {
   updates?: UpdatesSchedule;
   version?: string;
 }
+
+export type PoolMode = 'session' | 'statement' | 'transaction';
+
+export interface ConnectionPool {
+  database: string;
+  label: string;
+  mode: PoolMode;
+  size: number;
+  username: null | string;
+}

packages/manager/src/factories/databases.ts

@@ -1,5 +1,6 @@
 import {
   type ClusterSize,
+  type ConnectionPool,
   type Database,
   type DatabaseBackup,
   type DatabaseEngine,
@@ -160,6 +161,7 @@ export const databaseInstanceFactory =
         ? ([1, 3][i % 2] as ClusterSize)
         : ([1, 2, 3][i % 3] as ClusterSize)
     ),
+    connection_pool_port: null,
     connection_strings: [],
     created: '2021-12-09T17:15:12',
     encrypted: false,
@@ -211,6 +213,7 @@ export const databaseInstanceFactory =
 export const databaseFactory = Factory.Sync.makeFactory<Database>({
   allow_list: [...IPv4List],
   cluster_size: Factory.each(() => pickRandom([1, 3])),
+  connection_pool_port: null,
   connection_strings: [
     {
       driver: 'python',
@@ -285,6 +288,15 @@ export const databaseEngineFactory = Factory.Sync.makeFactory<DatabaseEngine>({
   version: Factory.each((i) => `${i}`),
 });
 
+export const databaseConnectionPoolFactory =
+  Factory.Sync.makeFactory<ConnectionPool>({
+    database: 'defaultdb',
+    mode: 'transaction',
+    label: Factory.each((i) => `pool/${i}`),
+    size: 10,
+    username: null,
+  });
+
 export const mysqlConfigResponse = {
   binlog_retention_period: {
     description:

packages/queries/.changeset/pr-13148-upcoming-features-1764600420579.md

@@ -0,0 +1,5 @@
+---
+"@linode/queries": Upcoming Features
+---
+
+Added Database Connection Pool queries ([#13148](https://github.com/linode/manager/pull/13148))

packages/queries/src/databases/databases.ts

@@ -1,13 +1,16 @@
 import {
   createDatabase,
+  createDatabaseConnectionPool,
   deleteDatabase,
+  deleteDatabaseConnectionPool,
   legacyRestoreWithBackup,
   patchDatabase,
   resetDatabaseCredentials,
   restoreWithBackup,
   resumeDatabase,
   suspendDatabase,
   updateDatabase,
+  updateDatabaseConnectionPool,
 } from '@linode/api-v4/lib/databases';
 import { profileQueries, queryPresets } from '@linode/queries';
 import {
@@ -22,6 +25,7 @@ import { databaseQueries } from './keys';
 
 import type {
   APIError,
+  ConnectionPool,
   CreateDatabasePayload,
   Database,
   DatabaseBackup,
@@ -194,6 +198,80 @@ export const useDatabaseBackupsQuery = (
     enabled,
   });
 
+export const useDatabaseConnectionPool = (
+  databaseId: number,
+  poolName: string,
+  enabled: boolean = false,
+) =>
+  useQuery<ConnectionPool, APIError[]>({
+    ...databaseQueries
+      .database('postgresql', databaseId)
+      ._ctx.connectionPools._ctx.pool(poolName),
+    enabled,
+  });
+
+export const useDatabaseConnectionPools = (
+  databaseId: number,
+  enabled: boolean = false,
+) =>
+  useQuery<ResourcePage<ConnectionPool>, APIError[]>({
+    ...databaseQueries.database('postgresql', databaseId)._ctx.connectionPools
+      ._ctx.pools,
+    enabled,
+  });
+
+export const useCreateDatabaseConnectionPoolMutation = (databaseId: number) => {
+  const queryClient = useQueryClient();
+  return useMutation<ConnectionPool, APIError[], ConnectionPool>({
+    mutationFn: (data) => createDatabaseConnectionPool(databaseId, data),
+    onSuccess() {
+      queryClient.invalidateQueries(
+        databaseQueries.database('postgresql', databaseId)._ctx.connectionPools,
+      );
+    },
+  });
+};
+
+export const useUpdateDatabaseConnectionPoolMutation = (
+  databaseId: number,
+  poolName: string,
+) => {
+  const queryClient = useQueryClient();
+  return useMutation<ConnectionPool, APIError[], Omit<ConnectionPool, 'label'>>(
+    {
+      mutationFn: (data) =>
+        updateDatabaseConnectionPool(databaseId, poolName, data),
+      onSuccess(connectionPool) {
+        queryClient.setQueryData<ConnectionPool>(
+          databaseQueries
+            .database('postgresql', databaseId)
+            ._ctx.connectionPools._ctx.pool(connectionPool.label).queryKey,
+          connectionPool,
+        );
+      },
+    },
+  );
+};
+
+export const useDeleteDatabaseConnectionPoolMutation = (
+  databaseId: number,
+  poolName: string,
+) => {
+  const queryClient = useQueryClient();
+  return useMutation<{}, APIError[]>({
+    mutationFn: () => deleteDatabaseConnectionPool(databaseId, poolName),
+    onSuccess() {
+      queryClient.invalidateQueries(
+        databaseQueries.database('postgresql', databaseId)._ctx.connectionPools,
+      );
+      queryClient.removeQueries({
+        queryKey: databaseQueries.database('postgresql', databaseId)._ctx
+          .connectionPools.queryKey,
+      });
+    },
+  });
+};
+
 export const useDatabaseEnginesQuery = (enabled: boolean = false) =>
   useQuery<DatabaseEngine[], APIError[]>({
     ...databaseQueries.engines,

packages/queries/src/databases/keys.ts

@@ -1,5 +1,7 @@
 import {
   getDatabaseBackups,
+  getDatabaseConnectionPool,
+  getDatabaseConnectionPools,
   getDatabaseCredentials,
   getDatabaseEngineConfig,
   getDatabases,
@@ -30,6 +32,19 @@ export const databaseQueries = createQueryKeys('databases', {
         queryFn: () => getDatabaseCredentials(engine, id),
         queryKey: null,
       },
+      connectionPools: {
+        contextQueries: {
+          pool: (poolName: string) => ({
+            queryFn: () => getDatabaseConnectionPool(id, poolName),
+            queryKey: [poolName],
+          }),
+          pools: {
+            queryFn: () => getDatabaseConnectionPools(id),
+            queryKey: null,
+          },
+        },
+        queryKey: null,
+      },
     },
     queryFn: () => getEngineDatabase(engine, id),
     queryKey: [engine, id],

packages/validation/.changeset/pr-13148-upcoming-features-1764600446107.md

@@ -0,0 +1,5 @@
+---
+"@linode/validation": Upcoming Features
+---
+
+Added Database Connection Pool schemas ([#13148](https://github.com/linode/manager/pull/13148))

packages/validation/src/databases.schema.ts

@@ -217,3 +217,22 @@ export const createDynamicAdvancedConfigSchema = (allConfigurations: any[]) => {
     ),
   });
 };
+
+export const createDatabaseConnectionPoolSchema = object({
+  database: string().required('Database is required'),
+  mode: string()
+    .oneOf(['transaction', 'session', 'statement'], 'Pool mode is required')
+    .required('Pool mode is required'),
+  label: string()
+    .required('Name is required')
+    .max(63, 'Name must not exceed 63 characters'),
+  size: number().required('Size is required'),
+  username: string().nullable().required('Username is required'),
+});
+
+export const updateDatabaseConnectionPoolSchema = object({
+  database: string().optional(),
+  mode: string().oneOf(['transaction', 'session', 'statement']).optional(),
+  size: number().optional(),
+  username: string().nullable().optional(),
+});