httpcaddyfile: Improve directive sorting logic

[francislavoie]

See discussion in https://caddy.community/t/v2-help-with-path-regexp-and-rewrite/9442/11

I'm pretty sure that it's almost always incorrect to sort root handlers from the Caddyfile in the same order as other directives, because it's essentially setting a variable, so only the last one run will apply - so you want the last one run to be the most-specific one.

Also, see the discussion in https://caddy.community/t/presenting-different-content-based-on-origin-of-request/9467/7

If a directive has any kind of matcher, it should still sort before a directive of the same name with no matcher at all.

[mholt]

Thanks for the change and the tests!

Some logic needs to be corrected and we should probably include other directives that need to be sorted differently...

Actually... root, along with the rewrite and handle directives are already mutually-exclusive of other instances of the same directive. I wonder if all of those would need to be added here, along with header...

[francislavoie]

Hmm. Looks like we have a flaky test with the Caddyfile adapter. For some reason on some environments, the first group is 0, and sometimes it's 1. 🤔

[mholt]

LGTM now, thanks for looking into this!

[mholt]

Note that the issue at https://caddy.community/t/v2-help-with-path-regexp-and-rewrite/9442 is not resolved by this because we don't (can't?) sort path_regexp matcher by length; only path.

[francislavoie]

Note that the issue at caddy.community/t/v2-help-with-path-regexp-and-rewrite/9442 is not resolved by this because we don't (can't?) sort path_regexp matcher by length; only path.

Actually it is resolved, because having a named matcher will now sort ahead of *, but mutual exclusivity will prevent the * one from taking effect altogether.

:8881

root * /foo

@regexp path_regexp bar ^/z(.*)$
root @regexp /bar

respond "Root: {http.vars.root}"

{
	"apps": {
		"http": {
			"servers": {
				"srv0": {
					"listen": [
						":8881"
					],
					"routes": [
						{
							"group": "group0",
							"match": [
								{
									"path_regexp": {
										"name": "bar",
										"pattern": "^/z(.*)$"
									}
								}
							],
							"handle": [
								{
									"handler": "vars",
									"root": "/bar"
								}
							]
						},
						{
							"group": "group0",
							"handle": [
								{
									"handler": "vars",
									"root": "/foo"
								}
							]
						},
						{
							"handle": [
								{
									"body": "Root: {http.vars.root}",
									"handler": "static_response"
								}
							]
						}
					]
				}
			}
		}
	}
}

$ curl localhost:8881/
Root: /foo

$ curl localhost:8881/zabc
Root: /bar

[mholt]

Ah, indeed, I was thinking more generally I guess, that this won't sort path_regexp matchers relative to path matchers.

Will merge this in a sec.