filters/builtin: drop specified header value #3457
Conversation
AlexanderYastrebov
added
enhancement
major
| header.Del(f.key) | ||
| } else { | ||
| k := textproto.CanonicalMIMEHeaderKey(f.key) | ||
| header[k] = slices.DeleteFunc(header[k], func(v string) bool { return v == f.value }) |
There was a problem hiding this comment.
I think value should also be case insensitive.
There was a problem hiding this comment.
My idea was to have a low-level primitive to drop a specific value.
For setting and adding header we do not do any modification to the value.
To support regexp we may consider changing modRequestHeader such that it deletes the matching header if "the replacement (string)" parameter is empty (or absent) or maybe add a whole new filter.
There was a problem hiding this comment.
I think we should add another filter dropRequestHeaderRegexp maybe?
There was a problem hiding this comment.
Yes, but I'd wait until we have a usecase for regexp value.
This change is useful to mitigate #3456
There was a problem hiding this comment.
Could a third boolean parameter to enable case-insensitive comparison be an alternative to regex?
There was a problem hiding this comment.
It could be done like that of course but lets wait for the usecase.
I initially considered to add a new filter dropRequestHeaderValue then decided to extend existing one but we should wary about how much logic we cram into it.
These header filters are basic primitives and building blocks and I think we should keep them simple. For higher-level or interesting logic we can always add new filters.
There was a problem hiding this comment.
I think we should add another filter dropRequestHeaderRegexp maybe?
Indeed, thanks, a new dropRequestHeaderRegexp would be better because exact value match is a very simple regexp (foo -> ^foo$ ), stdlib handles it as a special case of fast prefix check, we already use it e.g. in HeaderRegexp and it covers many other usecases.
There was a problem hiding this comment.
Could a third boolean parameter to enable case-insensitive comparison be an alternative to regex?
This could be achieved by regexp flags (e.g. ^(?i)foo$)
Extend `dropRequestHeader` and `dropResponseHeader` to support optional second value argument and drop only this value when specified. Signed-off-by: Alexander Yastrebov <[email protected]>
AlexanderYastrebov
force-pushed
the
filters/builtin/drop-header-value
branch
from
17cabc6 to
fc717bb
Compare
Extend
dropRequestHeaderanddropResponseHeaderto support optional second value argument and drop only this value when specified.