feat: delete inactive users and index

* rfc remove.

Author: pajgo

rfcs/inactive_users/user_cleanup.md

@@ -6,75 +6,31 @@ A lot of linked keys remain in the database, and this leads to keyspace pollutio
 For better data handling and clean database structure, I introduce some changes in service logic:
 
 ## General defs
-  - `inactive-users`
-  Redis database sorted set key. Assigned to `USER_ACTIVATE` constant.
-  Record contains `userId` as value and `timestamp` as score. 
-  - `user-audiences` [Described here](update_metadata_lua.md#audience-list-update)
-  - `deleteInactivatedUsers` Redis script, handling all cleanup logic.
+  - `inactive-users` [Described here](#inactive-users-index) 
+  - `user-audiences` [Described here](user_and_organization_meta_update.md)
 
-## Organization Members
-The `organization add member` process doesn't have validation whether the user passed activation and allows
-inviting inactive users into an organization. The script checks whether inactivated user assigned to any organization
-and deletes users from organization members and user->organization bindings.
+## `inactive-users` index
+It's an Additional Redis Sorted Set which contains the list of IDs of the `inactive` users.
+Each item score is equal to the `timestamp` set on user creation.
+To avoid hardcoded SET name new `USERS_INACTIVATED` constant introduced.
 
-## Registration and activation
-Every Activation and Registration request event executes  `users:cleanup`  hook.
-The Activation request executes the hook first this strategy saves from inactive
-users that hit TTL but tried to pass the activation process.
-The Registration request executes the hook after `username` exists check.
-
-## Registration process
+#### Registration process
 When the user succeeds registration but activation not requested, the new entry added to `inactive-users`.
-Record contains `userId` and `current timestamp`.
-
-## Activation process
-When the user succeeds activation `userId`,the entry deleted from `inactive-users`.
 
-## `users:cleanup` hook `cleanUsers(suppress?)`
-`suppress` parameter defines function error behavior. If parameter set, the function throws errors,
-otherwise, function calls `log.error` with `error.message` as message.
-Default value is `true`. IMHO User shouldn't know about our problems.
+**NOTE:** Old Redis `expire` setting methods left in their place, to save old service behavior.
 
-Other option, is to define new config parameter as object and move `config.deleteInactiveAccounts` into it:
-```javascript
-const conf = {
-  deleteInactiveUsers: {
-    ttl: seconds, // replaces deleteInactiveAccounts
-    suppressErrors: true || false,
-  },
-}
-```
-Calls `deleteInactivatedUsers` script with TTL parameter from `service.config.deleteInactiveAccounts`.
-When script finished, calls TokenManager to delete Action tokens(`USER_ACTION_*`, ``). 
-*NOTE*: Should we update TokenManager to add support of pipeline?
+#### Activation process
+When the user succeeds activation the entry deleted from `inactive-users`.
 
-## Redis Delete Inactive User Script
-When the service connects to the Redis server and fires event "plugin:connect:$redisType" `utils/inactive/defineCommand.js` executed.
-Function rendering `deleteInactivatedUsers.lua.hbs` and evals resulting script into IORedis.
-The Script using a dozen constants, keys, and templates, so all these values rendered inside of the template using template context.
-Returns list of deleted users.
+#### Index cleanup
+On `registration` cleanup method executes before user creation.
+On `activation` cleanup method executes before any checks performed by `activation` action.
+* Uses `dlock` for itself to be sure that only one process runs.
+* Gets outdated user list and deletes them.
 
-*NOTE*: Using experimental `fs.promises.readFile` API function. On `node` 10.x it's an experimental feature,
-on `node` >= 11.x function becomes stable without any changes in API.
-
-#### deleteInactivatedUsers `USERS_ACTIVATED` `TTL` as seconds
-##### Script paramerters:
-1. KEYS[1] Sorted Set name containing the list of users that didn't pass activation.
-2. ARGS[1] TTL in seconds.
-
-##### When started:
-1. Gets UserId's from ZSET `USERS_ACTIVATED` where score < `now() - TTL * 1000` and iterates over them.
-2. Gets dependent userData such as username, alias, and SSO provider information used in delete procedure and calls [Delete process](#delete-process).
-3. Deletes processed user ids from `USER_ACTIVATED` key.
+## TODO Organization Members Need additional information
+The `organization add member` process doesn't have validation whether the user passed activation and allows
+inviting inactive users into an organization. The script checks whether inactivated user assigned to any organization
+and deletes users from organization members and user->organization bindings.
 
-##### Delete process 
-The main logic is based on `actions/removeUsers.js`.
-Using the username, id, alias and SSO providers fields, script checks and removes dependent data from the database:
-* Alias to id binding.
-* Username to id binding.
-* All assigned metadata. Key names rendered from the template and `user-audiences`.
-* SSO provider to id binding. Using `SSO_PROVIDERS` items as the field name decodes and extracts UID's from Internal data.
-* User tokens.
-* Private and public id indexes
-* Links and data used in Organization assignment