client_cache_control_behavior.md

Client Cache Control Behavior

Caching is one of the best ways to optimization Application response time and reduce the load on web/app servers. Doing Caching at ADC layer is much more effective as it can be done along with other ADC operations. Though when you Cache content, you can control what to Cache on ADC and what Client should be caching. This use case focuses on controlling end client caching behavior with respect to different kind of content.

More details on controlling cache on Avi Vantage: https://avinetworks.com/docs/latest/overview-of-http-cache/

Apply this to the "HTTP RESPONSE" Event.

-- HTTP_RESPONSE
content_path = avi.http.get_path()
content_header = avi.http.get_header("content-type")
-- StringGroups can be used as alternative to lua tables
expires_file_types = {["gif"]="Wed, 2 May 2018 00:00:00 GMT", ["png"]="Wed, 2 May 2018 00:00:00 GMT", ["ico"]="Wed, 2 May 2018 00:00:00 GMT"}
cache_control_file_types = {["xml"]="max-age=600", ["js"]="max-age=500", ["flv"]="max-age=400"}

for key, value in pairs(expires_file_types) do
  if string.endswith(content_path, key) and string.endswith(content_header, key) then
    avi.http.replace_header("Expires", value)
  end
end

for key, value in pairs(cache_control_file_types) do
  if string.endswith(content_path, key) and string.endswith(content_header, key) then
    avi.http.replace_header("Cache-Control", value)
  end
end