There has been a lot of discussion on this and the related change for the URL port. You can see some of this on the ASF slack channel, but I will summarize in this note.
Leif objected to this change and the current compromise is to 1. Change the current TSUrlSchemeGet to do what was proposed for TSHttpHdrSchemeGet, that is if the scheme is not literally in the URL, the value in the internal member is used to return the WKS for the value. 2. Add TSUrlRawSchemeGet which does what TSUrlSchemeGet does now. In practice, this would be renaming TSUrlSchemeGet to TSUrlRawSchemeGet, and add TSUrlSchemeGet to do the "clever" thing. In the same way, do this for TSUrlPortGet and TSUrlRawPortGet. In essence TSUrlSchemeGet and TSUrlPortGet return the effective value, and the "Raw" variants get the literal value. This may need to be updated in the future for HTTP/2 outbound where the scheme can be set in an HTTP/2 field. OTOH if it is a field that could be handled the same way as for "Host" currently, which is by leaving the. burden of checking that to the plugin. On Tue, Sep 29, 2020 at 9:38 AM Alan Carroll < solidwallofc...@verizonmedia.com> wrote: > I don't see how this would depend on a cache hit or miss. If two requests > map to the same object, that's the cache key, not the request scheme. This > returns the scheme in hdr->m_http->req.m_url_impl.scheme or > hdr->m_http->req.m_url_impl.m_url_type if the former is nullptr. > > The point here is to provide access to data that is in the core but not > currently available to a plugin, that is > hdr->m_http->req.m_url_impl.m_url_type. Consider the case where a user > agent sends a request for "http://delain.nl/lucidity.html";. When the > proxy request is created, it will have only "lucidity.html" in the request > URL. Yet, unless the scheme was explicitly changed via a plugin or remap, > the core still knows it's an HTTP request. But how could a plugin know? > TSUrlSchemeGet will return a nullptr. In this case, however, > TSHttpHdrSchemeGet would return "http". > > This is very similar to TSHttpHdrHostGet, and is useful for the same > reasons. > > > On Mon, Sep 28, 2020 at 9:13 PM Leif Hedstrom <zw...@apache.org> wrote: > >> Also what’s the semantic here when both http:// and https:// URLs map >> to the same cached object ? The first cached request specifies the scheme? >> This seems confusing at best... or are we talking about the scheme as it >> goes to origin (which would have to be the same for both). >> >> Seems like a remap plugin could just look at the FromURL (or ToURL) which >> should have the scheme, rather than the cached data. And no new APIs >> needed. For a global plugins it’s less obvious, but same issues o think? >> >> — Leif >> >> > On Sep 28, 2020, at 20:05, Leif Hedstrom <zw...@apache.org> wrote: >> > >> > The point here being to make a new API that replaces the old, without >> breaking compatibility? And this new API has special semantics on a cache >> hit vs cache miss? >> > >> > This seems pretty convoluted, making it difficult for plugin writers to >> use the right API... >> > >> > — Leif >> > >> >> On Sep 28, 2020, at 19:49, Brian Neradt <brian.ner...@gmail.com> >> wrote: >> >> >> >> +1 >> >> >> >> Traffic Dump can make use of this. >> >> >> >>> On Mon, Sep 28, 2020 at 7:38 PM Walt Karas <wka...@verizonmedia.com >> .invalid> >> >>> wrote: >> >>> >> >>> This should get the scheme for the request. This differs from >> >>> `TSUrlSchemeGet` in that it gets the scheme even if it is not in the >> URL of >> >>> the request. For most proxy requests, the ATS core will remove the >> host and >> >>> scheme in the request while tracking it internally. In such a case a >> plugin >> >>> cannot discover that information, a problem this API would fix. >> >>> >> >>> If the scheme is in the request URL, return that. Otherwise return a >> scheme >> >>> that corresponds to the internally stored scheme. >> >>> >> >> >> >> >> >> -- >> >> "Come to Me, all who are weary and heavy-laden, and I will >> >> give you rest. Take My yoke upon you and learn from Me, for >> >> I am gentle and humble in heart, and you will find rest for >> >> your souls. For My yoke is easy and My burden is light." >> >> >> >> ~ Matthew 11:28-30 >> >>
