We’ve run into some issues trying to incrementally deploy remap rule plugin
changes to our CDN.
One HACKISH way we’ve identified how to do that is by creating an ANY_MAP
delivery service and using the Raw Remap Text line to put the change.
To make this work I’ve added a change to ORT to preprocess the remap.config
file to look for a commented keyword to do this.
So for example the current active DS FOO_ORIG might create an ATS remap rule
like the following:
map http://from.foo http://to.bar
We might want to test a new ATS remap rule:
map http://from.foo http://to.bar @plugin=collapsed_forwarding.so
to deploy on a subset of caches.
So we would create FOO_ANY_MAP as ANY_MAP with raw remap text:
##OVERRIDE## map http://from.foo http://to.bar
@plugin=collapsed_forwarding.so
With those subset of caches now being assigned to both FOO_ORIG and FOO_ANY_MAP.
During processing the modified traffic_ops_ort.pl script removes the
‘##OVERRIDE## ‘ from the above rule and also removes the existing FOO_ORIG ‘map
http://from.foo http://to.bar’ (based on endpoint match http://from.foo) from
the remap.config file.
I had wanted to leave comments in the remap.config file to clearly point out
the override and keep the original line in the file but commented out, however
that would require either modifying the global logic for change detection or
writing a custom remap.config change detection routine.
This updated version of traffic_ops_ort.pl script would need to be deployed
before using this ##OVERRIDE## method as will trigger a false positive change
in remap.txt every time queues are updated.
This is a HACK designed only live until we get something like versioned
delivery services into trafficontrol proper.
Please let me know of any issues, better ways to do the above, etc.
Thanks!
Brian
