feat(egress-proxy): retarget remediation flow (PRD 0017 chunk 3) #30

Merged
didericis merged 18 commits from egress-proxy-block-remediation into main 2026-05-25 20:34:24 -04:00
2 changed files with 81 additions and 5 deletions
Showing only changes of commit 811a6fbfe9 - Show all commits
+23 -5
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@@ -169,15 +169,33 @@ def match_route(
routes: typing.Sequence[Route],
request_host: str,
) -> Route | None:
"""Return the first route whose `host` matches `request_host`.
"""Return the route whose `host` matches `request_host`.
Exact match in v1 — globs / wildcards are a follow-up (per PRD
0017 open questions). Hostname comparison is case-insensitive
because DNS names are case-insensitive."""
Match precedence:
1. Exact (case-insensitive) match on the literal hostname.
2. Wildcard match: a route whose host starts with `*.` is a
suffix pattern. `*.example.com` matches any host that
ends with `.example.com` (so `foo.example.com` and
`a.b.example.com`, but NOT the apex `example.com` or
`barexample.com`).
Exact match wins over wildcard so an operator can declare a
specific route on top of a broader wildcard (e.g. a
`*.github.com` bare-pass + an `api.github.com` route with
auth). DNS names are case-insensitive."""
target = request_host.lower()
# Pass 1: exact, literal hostname match.
for r in routes:
if r.host.lower() == target:
host = r.host.lower()
if not host.startswith("*.") and host == target:
return r
# Pass 2: wildcard suffix match (`*.foo.com` → `.foo.com`).
for r in routes:
host = r.host.lower()
if host.startswith("*."):
suffix = host[1:] # keeps the leading `.`
if target.endswith(suffix) and target != suffix[1:]:
return r
return None
@@ -148,6 +148,64 @@ class TestMatchRoute(unittest.TestCase):
self.assertIsNone(match_route(self.ROUTES, "evil.api.github.com"))
class TestMatchRouteWildcards(unittest.TestCase):
"""Wildcard host patterns: `*.foo.com` matches any host that
ends with `.foo.com` (subdomains, one level or more)."""
def test_wildcard_matches_direct_subdomain(self):
routes = (Route(host="*.example.com"),)
r = match_route(routes, "foo.example.com")
self.assertIsNotNone(r)
self.assertEqual("*.example.com", r.host)
def test_wildcard_matches_nested_subdomain(self):
routes = (Route(host="*.example.com"),)
self.assertIsNotNone(match_route(routes, "a.b.example.com"))
def test_wildcard_does_not_match_apex(self):
routes = (Route(host="*.example.com"),)
self.assertIsNone(match_route(routes, "example.com"))
def test_wildcard_does_not_match_overlapping_suffix(self):
# `*.example.com` shouldn't match `barexample.com` — the
# match requires `.` before the suffix.
routes = (Route(host="*.example.com"),)
self.assertIsNone(match_route(routes, "barexample.com"))
def test_wildcard_case_insensitive(self):
routes = (Route(host="*.example.com"),)
self.assertIsNotNone(match_route(routes, "FOO.Example.COM"))
def test_exact_match_wins_over_wildcard(self):
# A specific route declared alongside a broader wildcard
# should take precedence — operators stack a per-host
# config on top of a permissive wildcard this way.
routes = (
Route(host="*.github.com"),
Route(host="api.github.com", auth_scheme="Bearer",
token_env="EGRESS_PROXY_TOKEN_0"),
)
r = match_route(routes, "api.github.com")
self.assertIsNotNone(r)
self.assertEqual("api.github.com", r.host)
self.assertEqual("Bearer", r.auth_scheme)
def test_exact_wins_regardless_of_route_order(self):
# Same as above but with wildcard declared AFTER exact —
# exact wins because pass 1 finds it before pass 2 runs.
routes = (
Route(host="api.github.com", auth_scheme="Bearer",
token_env="EGRESS_PROXY_TOKEN_0"),
Route(host="*.github.com"),
)
r = match_route(routes, "api.github.com")
self.assertEqual("api.github.com", r.host)
def test_no_match_falls_through(self):
routes = (Route(host="*.example.com"),)
self.assertIsNone(match_route(routes, "elsewhere.org"))
# --- decide --------------------------------------------------------------