Match on header

[splushii]

Currently, we only support matching on path, query (and domain / Host header via domains). There are usecases which would benefit from header matching.

[ghost]

This is dependent on multi-dimensional collision detection as described in #12

[splushii]

We probably want to consider how domains works when implementing header matching (because domains actually does header matching but specifically for the field host)

[splushii]

My general idea is to

• Update schema to support header matching (and deprecate domain?)
• Update schema to support specifying headers for ORM tests
• Deployment tests
• Implement changes in parser, validator, and varnish render
• Support setting headers in runtests.py
• Collision check header matches in validator
  • Add domain value to Host header for collision checking
  • Do not split collision checking on domain value (because there may be no domain). Alternatively, continue to split it and use an empty domain as one part of the split.
  • Handle domain_default collision checking (to incorporate the Host header). Alternatively, make domains required if domain_default is true.
• Unit tests
• Update docs

[splushii]

Just a note to self. We need to make domains optional if we want to have sane support for matching on host headers with the new header matching.

[pascalgagneur]

Will this provide functionality to route to precompressed files depending on
"accept-encoding: gzip, deflate, br" header?

[splushii]

It will be possible to match headers with the following syntax:

header:
  field: accept-encoding
  exact: "gzip, deflate, br"

It will also be possible to use regex, begins_with, etc instead of exact, like other matching methods.