Redacting person audit log howto

doc/manual_procedures/redacting_person_audit_log.md

+Audit log edition if needed
+===========================
+
+Following a query from a DD to remove any log on his nm account about bio
+edition, I did some manual work to oblige, as there is no (yet) admin interface
+for PersonAuditLog objects.
+
+I'll summarize my manipulations here, including the obvious ones, in case they
+are not so obvious for someone else.
+
+A django shell
+--------------
+
+Here is a walkthrough of the commands I ran to get a django shell to remove what
+we needed to remove:
+
+```
+ssh nono.debian.org
+sudo -i -u nm
+exec /bin/bash (not mandatory, but I'm not happy with dash)
+cd ../nm2
+./manage.py shell
+```
+
+Find your dd
+------------
+
+There are plenty ways to find the DD you're looking for. I'm quite happy using
+their login, and therefore relying on the LDAP fields of a "person".
+
+```
+In [1]: from backend import models as bmodels
+
+In [2]: my_dd = bmodels.Person.objects.get(ldap_fields__uid="dduid")
+
+In [3]: my_dd
+Out[3]: My Redacted DD <my.redacted.dd@example.org> [uid:dduid, status:dd_u]
+```
+
+Find the interesting PersonAuditLog entries
+-------------------------------------------
+
+NM defines a PersonAuditLog as an object tied to Person with a related field
+name being "audit_log". Therefore finding all PersonAuditLog of a Person is
+quite straightforward as soon as you have the instance of Person you need:
+
+```
+In [4]: my_dd.audit_log.all()
+Out [4]: <QuerySet [REDACTED]>
+```
+
+A PersonAuditLog contains a "changes" field, which contains the litigious
+elements. It's a string containing a json.
+
+Here is how to remove the problematic changes:
+
+```
+In [5]: for entry in my_dd.audit_log.all():
+   ...:     if "bio" in entry.changes:
+   ...:         entry.delete()
+```
+
+This is irreversible so be sure you want to do that.
+
+An alternative could be to edit the json to redact the unneeded entries
+instead of wiping a full data. import json, json.loads(), yadda yadda.
+
+-- 
+PEB on nov the 27th 2021