[7.8] [kbn/es] retry fetching native realm users (elastic#66511) (ela…

…stic#66619)

packages/kbn-es/src/utils/native_realm.js

@@ -76,10 +76,6 @@ exports.NativeRealm = class NativeRealm {
     }
 
     const reservedUsers = await this.getReservedUsers();
-    if (!reservedUsers || reservedUsers.length < 1) {
-      throw new Error('no reserved users found, unable to set native realm passwords');
-    }
-
     await Promise.all(
       reservedUsers.map(async user => {
         await this.setPassword(user, options[`password.${user}`]);
@@ -88,16 +84,18 @@ exports.NativeRealm = class NativeRealm {
   }
 
   async getReservedUsers() {
-    const users = await this._autoRetry(async () => {
-      return await this._client.security.getUser();
-    });
+    return await this._autoRetry(async () => {
+      const resp = await this._client.security.getUser();
+      const usernames = Object.keys(resp.body).filter(
+        user => resp.body[user].metadata._reserved === true
+      );
 
-    return Object.keys(users.body).reduce((acc, user) => {
-      if (users.body[user].metadata._reserved === true) {
-        acc.push(user);
+      if (!usernames?.length) {
+        throw new Error('no reserved users found, unable to set native realm passwords');
       }
-      return acc;
-    }, []);
+
+      return usernames;
+    });
   }
 
   async isSecurityEnabled() {
@@ -125,10 +123,9 @@ exports.NativeRealm = class NativeRealm {
         throw error;
       }
 
-      this._log.warning(
-        'assuming [elastic] user not available yet, waiting 1.5 seconds and trying again'
-      );
-      await new Promise(resolve => setTimeout(resolve, 1500));
+      const sec = 1.5 * attempt;
+      this._log.warning(`assuming ES isn't initialized completely, trying again in ${sec} seconds`);
+      await new Promise(resolve => setTimeout(resolve, sec * 1000));
       return await this._autoRetry(fn, attempt + 1);
     }
   }