feat: add "application_name" as an optional DB option #1170 (#1478)

* implemented changes to resolve issue 1170

* added applicationName to the list of db options in the documentation'

Co-authored-by: Daniele Casal <daniele.casal@lloydsbanking.com>
Co-authored-by: Sukhvinder Panesar <79143027+esspee-lbg@users.noreply.github.com>

src/lib/__snapshots__/create-config.test.ts.snap

@@ -11,6 +11,7 @@ Object {
   },
   "db": Object {
     "acquireConnectionTimeout": 30000,
+    "applicationName": "unleash",
     "database": "unleash_db",
     "disableMigration": false,
     "driver": "postgres",

src/lib/create-config.ts

@@ -95,6 +95,7 @@ const defaultDbOptions: IDBOption = {
     },
     schema: process.env.DATABASE_SCHEMA || 'public',
     disableMigration: false,
+    applicationName: process.env.DATABASE_APPLICATION_NAME || 'unleash',
 };
 
 const defaultSessionOption: ISessionOption = {

src/lib/db/db-pool.ts

@@ -9,7 +9,10 @@ export function createDb({
     return knex({
         client: 'pg',
         version: db.version,
-        connection: db,
+        connection: {
+            ...db,
+            application_name: db.applicationName,
+        },
         pool: db.pool,
         searchPath: db.schema,
         asyncStackTraces: true,

src/lib/types/option.ts

@@ -30,6 +30,7 @@ export interface IDBOption {
     };
     schema: string;
     disableMigration: boolean;
+    applicationName?: string;
 }
 
 export interface ISessionOption {

src/server-dev.ts

@@ -16,6 +16,7 @@ process.nextTick(async () => {
                     database: process.env.UNLEASH_DATABASE_NAME || 'unleash',
                     schema: process.env.UNLEASH_DATABASE_SCHEMA,
                     ssl: false,
+                    applicationName: 'unleash',
                 },
                 server: {
                     enableRequestLogger: true,

website/docs/deploy/configuring-unleash.md

@@ -205,6 +205,7 @@ The available options are listed in the table below. Options can be specified ei
 | `pool.min`               | `DATABASE_POOL_MIN`             | 0              | The minimum number of connections in the connection pool.                                                                                                                                |
 | `pool.max`               | `DATABASE_POOL_MAX`             | 4              | The maximum number of connections in the connection pool.                                                                                                                                |
 | `pool.idleTimeoutMillis` | `DATABASE_POOL_IDLE_TIMEOUT_MS` | 30000          | The amount of time (in milliseconds) that a connection must be idle for before it is marked as a candidate for eviction.                                                                 |
+| `applicationName`        | `DATABASE_APPLICATION_NAME`     | `unleash`      | The name of the application that created this Client instance.                                                                                    |
 
 Alternatively, you can use a [libpq connection string](https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING) to connect to the database. You can provide it directly or from a file by using one of the below options. In JavaScript, these are top-level properties of the root configuration object, *not* the `db` object.