[AMS Dispatcher] A new flush vhost to invalidate author cache

[YegorKozlov]

Description

The PR adds a new vhost to invalidate cache on author dispatcher in AMS setups.

Related Issue

#1037

Motivation and Context

The current AMS Dispatcher configuration does not provide a way to flush cache on author dispatcher. Flush requests always resolve to a publisher farm which invalidates content in publisher document root.

The PR adds a new "authorflush" vhost which resolves to the author farm. To use it from AEM you'd need to define a new Flush agent and set authorflush in the Host header:

How Has This Been Tested?

In our setup we use the Dispatcher Flush UI tool, but the problem is also reproducible from curl. Execute the commands below while tailing dispatcher.log :

Current behaviour using the default "flush" vhost.

curl http://localhost/dispatcher/invalidate.cache \
-H "CQ-Action: Delete" \
-H "CQ-Handle: /apps" \
-H "Host: flush"

dispatcher resolves publishfarm and invalidates publish docroot (/mnt/var/www/html)

[Sun Feb 05 13:17:45 2023] [W] [pid 18] No farm matches host 'flush', selected last farm 'publishfarm'
[Sun Feb 05 13:17:45 2023] [D] [pid 18] Found farm publishfarm for flush
[Sun Feb 05 13:17:45 2023] [D] [pid 18] checking [/dispatcher/invalidate.cache]
[Sun Feb 05 13:17:45 2023] [I] [pid 18] Activation detected: action=Delete [/apps]
[Sun Feb 05 13:17:45 2023] [I] [pid 18] Touched /mnt/var/www/html/.stat
[Sun Feb 05 13:17:45 2023] [D] [pid 18] response.status = 200

The fixed behaviour using the new "authorflush" vhost.

curl http://localhost/dispatcher/invalidate.cache \
-H "CQ-Action: Delete" \
-H "CQ-Handle: /apps" \
-H "Host: authorflush"

dispatcher resolves authorfarm and invalidates publish docroot (/mnt/var/www/author)

[Sun Feb 05 13:32:26 2023] [D] [pid 26] Found farm authorfarm for authorflush
[Sun Feb 05 13:32:26 2023] [D] [pid 26] checking [/dispatcher/invalidate.cache]
[Sun Feb 05 13:32:26 2023] [I] [pid 26] Activation detected: action=Delete [/apps]
[Sun Feb 05 13:32:26 2023] [I] [pid 26] Touched /mnt/var/www/author/.stat
[Sun Feb 05 13:32:26 2023] [D] [pid 26] response.status = 200

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.