DG-1735 | Fix for policy updates getting missed by PolicyRefresher

[krsoninikhil]

Change description

Currently, the PolicyRefresher fetches policies if it finds audit logs after last updated timestamp and then updates it's last updated time to current time. This PR adds a check on fetched data to check if it has the latest edited policies, otherwise try again. And don't update the last updated timestamp if latest data is not found.

Things to note:

• I'm ignoring the delete events for now and only capturing the T1 for other updates
• I'm checking for last policy update time (T2) after pulling all the policies. If sort by timestamp desc, risk is if more policies are added in the meantime, we won't get them and if no. of policies is large, ES might sync by the time we pull last page and if we sort in descending, we'll not get to take advantage of this.
• Anyway, this can be changed if required

Type of change

• Bug fix (fixes an issue)
• New feature (adds functionality)

Related issues

Fix #1

Checklists

Development

• Lint rules pass locally
• Application changes have been tested thoroughly
• Automated tests covering modified code pass

Security

• Security impact of change has been considered
• Code follows company security practices and guidelines

Code review

• Pull request has a descriptive title and context useful to a reviewer. Screenshots or screencasts are attached as necessary
• "Ready for review" label attached and reviewers assigned
• Changes have been reviewed by at least one other contributor
• Pull request linked to task tracker where applicable