feat: store login events (#3185)

## About the changes
https://linear.app/unleash/issue/2-705/store-sign-on-events

Adds a migration for a new `login_events` table. Also adds the new
`loginEventLog` feature flag.

<!-- (For internal contributors): Does it relate to an issue on public
roadmap? -->
Relates to [roadmap](https://github.com/orgs/Unleash/projects/10) item:
#2951

---------

Co-authored-by: Christopher Kolstad <chriswk@getunleash.ai>

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

@@ -74,6 +74,7 @@ exports[`should create default config 1`] = `
       "embedProxy": true,
       "embedProxyFrontend": true,
       "featuresExportImport": false,
+      "loginEventLog": false,
       "maintenance": false,
       "maintenanceMode": false,
       "messageBanner": false,
@@ -96,6 +97,7 @@ exports[`should create default config 1`] = `
       "embedProxy": true,
       "embedProxyFrontend": true,
       "featuresExportImport": false,
+      "loginEventLog": false,
       "maintenance": false,
       "maintenanceMode": false,
       "messageBanner": false,

src/lib/types/experimental.ts

@@ -67,6 +67,10 @@ const flags = {
         false,
     ),
     notifications: parseEnvVarBoolean(process.env.NOTIFICATIONS, false),
+    loginEventLog: parseEnvVarBoolean(
+        process.env.UNLEASH_LOGIN_EVENT_LOG,
+        false,
+    ),
 };
 
 export const defaultExperimentalOptions: IExperimentalOptions = {

src/migrations/20230222084211-add-login-events-table.js

@@ -0,0 +1,27 @@
+exports.up = function (db, cb) {
+    db.runSql(
+        `
+        CREATE TABLE IF NOT EXISTS login_events (
+            id SERIAL PRIMARY KEY NOT NULL,
+            username TEXT NOT NULL,
+            auth_type TEXT NOT NULL,
+            created_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT now(),
+            successful BOOLEAN NOT NULL,
+            ip INET,
+            failure_reason TEXT
+        );
+        CREATE INDEX IF NOT EXISTS login_events_ip_idx ON login_events(ip);
+    `,
+        cb,
+    );
+};
+
+exports.down = function (db, cb) {
+    db.runSql(
+        `
+        DROP INDEX IF EXISTS login_events_ip_idx;
+        DROP TABLE IF EXISTS login_events;
+    `,
+        cb,
+    );
+};