Chris_Phillips
Nimbostratus
Nimbostratuscaching images - ignore HTTP request?
Howdy,
I'm updating some inherited rules to cache images:
when HTTP_REQUEST {
set filematch 0
Check if requested URI ends with the cache control file types or
the Content-Type equals any of the cache control content types
if { ([class search cache_control_files_dgl ends_with [HTTP::uri]]) or \
([class search cache_control_types_dgl equals [HTTP::header Content-Type]])} {
set filematch 1
}
}
when HTTP_RESPONSE {
if { $filematch == 1 } {
HTTP::header replace "Cache-Control" "max-age=3600,post-check=3600,pre-check=43200"
}
}Secondly, it seems to me that checking the HTTP::uri is pretty pointless when you have the Content-Type available in the response. I'm looking at replacing it with just this:
when HTTP_RESPONSE {
if { [class search cache_control_types_dgl equals [HTTP::header Content-Type]] } {
HTTP::header replace "Cache-Control" "max-age=3600,post-check=3600,pre-check=43200"
} else {
HTTP::header replace "Pragma" "no-cache"
HTTP::header replace "Expires" "-1"
HTTP::header replace "Cache-Control" "no-cache,no-store,must-revalidate"
}
}Whilst it can seem "safer" to check the URI, why would you ever need to IF you trust your application to be returning a correct Content-Type header? That is surely much more trustworthy that the requested URI?
