[james-project] branch master updated: [ADR] Changing username (#1489)

[bt...@apache.org]

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in repository https://gitbox.apache.org/repos/asf/james-project.git


The following commit(s) were added to refs/heads/master by this push:
     new e2db9073b3 [ADR] Changing username (#1489)
e2db9073b3 is described below

commit e2db9073b308d72f4d61a98bf1b05d5c9886f127
Author: Trần Hồng Quân <55...@users.noreply.github.com>
AuthorDate: Mon Mar 20 04:11:47 2023 +0700

    [ADR] Changing username (#1489)
---
 src/adr/0064-account-delegation.md |  4 +--
 src/adr/0065-changing-username.md  | 51 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/src/adr/0064-account-delegation.md b/src/adr/0064-account-delegation.md
index 8bfadab8fc..db0105143d 100644
--- a/src/adr/0064-account-delegation.md
+++ b/src/adr/0064-account-delegation.md
@@ -6,7 +6,7 @@ Date: 2022-11-15
 
 Accepted (lazy consensus).
 
-Not yet implemented.
+Implemented.
 
 ## Context
 
@@ -43,6 +43,6 @@ The account delegation will help owner and delegated account:
 
 ## References
 
-- [JIRA](https://issues.apache.org/jira/browse/JAMES-xxx)
+- [JIRA](https://issues.apache.org/jira/projects/JAMES/issues/JAMES-3756)
 - [JMAP Sharing](https://datatracker.ietf.org/doc/draft-ietf-jmap-sharing/)
 - [James Delegation](https://github.com/apache/james-project/blob/master/src/adr/0061-delegation.md)
\ No newline at end of file
diff --git a/src/adr/0065-changing-username.md b/src/adr/0065-changing-username.md
new file mode 100644
index 0000000000..7a93016a1e
--- /dev/null
+++ b/src/adr/0065-changing-username.md
@@ -0,0 +1,51 @@
+# 65. Changing username
+
+Date: 2023-03-17
+
+## Status
+
+Accepted (lazy consensus).
+
+Implemented.
+
+## Context
+Changing username is a desired feature for an email server. It is a common practice especially when a user marries or divorces. For example:
+
+Alice MARTINEZ have an email address `alice.martinez@domain.tld` and gets married to Bob ERNANDEZ. She thus wants to
+change her email address to `alice.ernandez@domain.tld` while preserving her email data.
+
+Nowadays, James uses username as an identifier for user data. Therefore, this feature is hard to implement because of changing
+directly identifier to another value is difficult and could break data consistency if we do not do it carefully.
+
+## Decision
+We decided to do changing username with two steps: first, create new username, then migrate the old user's data to the new account -
+the way we expect that is less dangerous to current data consistency. The data in the old account need to be truncated after migrating to the new account.
+
+For the data migration step, we decided to form it under a webadmin task with a modular design. A big data migration task contains
+many small tasks that implement `UsernameChangeTaskStep` interface. This modular design for migration steps could help developers easier
+to manage/test each step, and help other tailor James servers can implement their own steps as well.
+
+Today, implemented migration steps are:
+
+- `ForwardUsernameChangeTaskStep`: creates forward from the old user to the new user and migrates existing forwards
+- `FilterUsernameChangeTaskStep`: migrates users filtering rules
+- `DelegationUsernameChangeTaskStep`: migrates delegations where the impacted user is either delegatee or delegator
+- `MailboxUsernameChangeTaskStep`: migrates mailboxes belonging to the old user to the account of the new user. It also
+  migrates users' mailbox subscriptions.
+- `ACLUsernameChangeTaskStep`: migrates ACLs on mailboxes the migrated user has access to and updates subscriptions accordingly.
+
+We introduce `fromStep` query parameter that allows skipping previous steps, allowing the operator to resume the username change from a failed step.
+This option could ease operators in case the data migration fails in the middle.
+
+## Consequences
+- Add one more useful feature to James rich feature set: Users can change their name while preserving their email data.
+- Modular design for changing username is extension friendly for tailor James servers.
+- Users would be aware that they have a new account through a new username/password. No implicit migration without user attention is archived today.
+- JMAP Identity data is not migrated because they are tightly coupled to the old username, users should create identities again themselves.
+- Some data considered not critical like Push subscription, Vacation response,... are not migrated today. Contributions for them are welcome.
+
+## Alternatives
+We could have another choice for implementing this topic: create an account identifier not linked directly to the username (e.g a hash value points to a username),
+so changing the pointer value would be easier than changing the pointer itself. However, that approach has two great concerns:
+- Huge refactoring/breaking change is required: nowadays username as an identifier is used everywhere in tables schema and code.
+- Performance concern: 1 more request is required every time we want to resolve the username.
\ No newline at end of file


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