fix(resolver): make GitHubTagProvider server URL configurable

e2e/common.sh

@@ -55,42 +55,45 @@ export NETWORK_ISOLATION
 export WHEEL_PLATFORM_TAG
 export HAS_ELFDEP
 
-# Local web server management
-HTTP_SERVER_PID=""
+# Background server management
+_BACKGROUND_PIDS=()
 on_exit() {
-    if [ -n "$HTTP_SERVER_PID" ]; then
-        echo "Stopping wheel server"
-        kill "$HTTP_SERVER_PID"
-    fi
+    # ${arr[@]+...} avoids "unbound variable" under set -u when empty
+    for pid in "${_BACKGROUND_PIDS[@]+"${_BACKGROUND_PIDS[@]}"}"; do
+        kill "$pid" 2>/dev/null || true
+    done
 }
 trap on_exit EXIT SIGINT SIGTERM
 
-start_local_wheel_server() {
-    local serve_dir="${1:-$OUTDIR/wheels-repo}"
-    # Use the builtin fromager wheel-server (Starlette/uvicorn) instead of
-    # stdlib http.server.  Binding to 127.0.0.1 is safe on all platforms
-    # because uv pip install always runs on the host without network
-    # isolation (build_environment.py hardcodes network_isolation=False).
-    fromager \
-        --wheels-repo="$serve_dir" \
-        wheel-server --port 9999 --address 127.0.0.1 &
-    HTTP_SERVER_PID=$!
-    export WHEEL_SERVER_URL="http://127.0.0.1:9999/simple"
+# start_background_server NAME HEALTH_URL COMMAND...
+start_background_server() {
+    local name="$1" health_url="$2"
+    shift 2
+
+    "$@" &
+    local pid=$!
+    _BACKGROUND_PIDS+=("$pid")
 
-    # Wait for the server to accept connections (up to 15 s).
     { set +x; } 2>/dev/null
     local ready=false
     for _ in $(seq 1 30); do
-        kill -0 "$HTTP_SERVER_PID" 2>/dev/null || break
-        curl -sf "http://127.0.0.1:9999/simple" >/dev/null 2>&1 && { ready=true; break; }
+        kill -0 "$pid" 2>/dev/null || break
+        curl -sf "$health_url" >/dev/null 2>&1 && { ready=true; break; }
         sleep 0.5
     done
     set -x
 
     if $ready; then
-        echo "Wheel server is ready"
+        echo "$name is ready"
         return 0
     fi
-    echo "ERROR: wheel server did not become ready" >&2
+    echo "ERROR: $name did not become ready" >&2
     return 1
 }
+
+start_local_wheel_server() {
+    local serve_dir="${1:-$OUTDIR/wheels-repo}"
+    start_background_server "Wheel server" "http://127.0.0.1:9999/simple" \
+        fromager --wheels-repo="$serve_dir" wheel-server --port 9999 --address 127.0.0.1
+    export WHEEL_SERVER_URL="http://127.0.0.1:9999/simple"
+}

e2e/github_override_example/mock_api/serve.py

@@ -0,0 +1,35 @@
+"""Minimal mock GitHub API server for e2e tests.
+
+Serves static tag JSON for the stevedore-test-repo at the expected
+GitHub API path.
+"""
+
+from __future__ import annotations
+
+import pathlib
+import sys
+from http.server import BaseHTTPRequestHandler, HTTPServer
+
+TAGS_PATH = "/repos/python-wheel-build/stevedore-test-repo/tags"
+TAGS_JSON = (pathlib.Path(__file__).parent / "tags.json").read_bytes()
+
+
+class Handler(BaseHTTPRequestHandler):
+    def do_GET(self) -> None:
+        if self.path == TAGS_PATH:
+            self.send_response(200)
+            self.send_header("Content-Type", "application/json")
+            self.end_headers()
+            self.wfile.write(TAGS_JSON)
+        else:
+            self.send_error(404)
+
+    def log_message(self, format: str, *args: object) -> None:
+        pass
+
+
+if __name__ == "__main__":
+    port = int(sys.argv[1]) if len(sys.argv) > 1 else 9998
+    server = HTTPServer(("127.0.0.1", port), Handler)
+    print(f"Mock GitHub API listening on http://127.0.0.1:{port}", flush=True)
+    server.serve_forever()

e2e/github_override_example/mock_api/tags.json

@@ -0,0 +1,52 @@
+[
+  {
+    "name": "5.4.1",
+    "zipball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/zipball/refs/tags/5.4.1",
+    "tarball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/tarball/refs/tags/5.4.1",
+    "commit": {
+      "sha": "27e27c116c0e8b84415d683e958780f4607ca3cc",
+      "url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/commits/27e27c116c0e8b84415d683e958780f4607ca3cc"
+    },
+    "node_id": "REF_kwDOO7Smz69yZWZzL3RhZ3MvNS40LjE"
+  },
+  {
+    "name": "5.4.0",
+    "zipball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/zipball/refs/tags/5.4.0",
+    "tarball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/tarball/refs/tags/5.4.0",
+    "commit": {
+      "sha": "016740e3cc7b0f254cb952296314d7ea7d9cdd20",
+      "url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/commits/016740e3cc7b0f254cb952296314d7ea7d9cdd20"
+    },
+    "node_id": "REF_kwDOO7Smz69yZWZzL3RhZ3MvNS40LjA"
+  },
+  {
+    "name": "5.3.0",
+    "zipball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/zipball/refs/tags/5.3.0",
+    "tarball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/tarball/refs/tags/5.3.0",
+    "commit": {
+      "sha": "51134a4dc04872df9f736e5ae52d4b665c40e364",
+      "url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/commits/51134a4dc04872df9f736e5ae52d4b665c40e364"
+    },
+    "node_id": "REF_kwDOO7Smz69yZWZzL3RhZ3MvNS4zLjA"
+  },
+  {
+    "name": "5.2.0",
+    "zipball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/zipball/refs/tags/5.2.0",
+    "tarball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/tarball/refs/tags/5.2.0",
+    "commit": {
+      "sha": "21d601f3f568f2a8b1b6447931a73554eb60703a",
+      "url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/commits/21d601f3f568f2a8b1b6447931a73554eb60703a"
+    },
+    "node_id": "REF_kwDOO7Smz69yZWZzL3RhZ3MvNS4yLjA"
+  },
+  {
+    "name": "5.1.0",
+    "zipball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/zipball/refs/tags/5.1.0",
+    "tarball_url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/tarball/refs/tags/5.1.0",
+    "commit": {
+      "sha": "2d99cccf9a6c04509785e76a5c8e89ae2824c939",
+      "url": "https://api.github.com/repos/python-wheel-build/stevedore-test-repo/commits/2d99cccf9a6c04509785e76a5c8e89ae2824c939"
+    },
+    "node_id": "REF_kwDOO7Smz69yZWZzL3RhZ3MvNS4xLjA"
+  }
+]

e2e/github_override_example/src/package_plugins/stevedore_github.py

@@ -1,3 +1,5 @@
+import os
+
 from packaging.requirements import Requirement
 
 from fromager import context, resolver
@@ -13,6 +15,10 @@ def get_resolver_provider(
     ignore_platform: bool = False,
 ) -> resolver.GitHubTagProvider:
     """Return a GitHubTagProvider for the stevedore test repo on github.com."""
+    kwargs: dict[str, str] = {}
+    github_api_url = os.environ.get("GITHUB_API_URL")
+    if github_api_url:
+        kwargs["server_url"] = github_api_url
     return resolver.GitHubTagProvider(
         organization="python-wheel-build",
         repo="stevedore-test-repo",
@@ -22,4 +28,5 @@ def get_resolver_provider(
             "https://github.com/{organization}/{repo}"
             "/archive/refs/tags/{tagname}.tar.gz"
         ),
+        **kwargs,
     )

e2e/test_bootstrap_cooldown_github.sh

@@ -5,8 +5,12 @@
 # the GitHubTagProvider, the cooldown is NOT enforced (because GitHub does not
 # yet provide upload timestamps), but a warning is emitted for each candidate.
 #
-# The stevedore test repo (python-wheel-build/stevedore-test-repo) is used as
-# a convenient GitHub-hosted package with known tags.
+# A local mock server serves static tag JSON instead of hitting the real GitHub
+# API, so the test is deterministic and does not consume rate-limited API calls.
+#
+# The stevedore test repo (python-wheel-build/stevedore-test-repo) tag structure
+# is reproduced in mock_api/tags.json.  The latest version is 5.4.1 (released
+# 2025-02-20 on the real repo).
 #
 # MIN_AGE is anchored to stevedore 5.4.1 (2025-02-20), so it is large enough
 # that enforcement WOULD block the resolved candidate — confirming that the
@@ -25,9 +29,16 @@ age = (date.today() - date(2025, 2, 20)).days
 print(age + 1)
 ")
 
+# Start a local mock GitHub API server.
+MOCK_API_DIR="$SCRIPTDIR/github_override_example/mock_api"
+GITHUB_MOCK_PORT=9998
+start_background_server "Mock GitHub API" \
+  "http://127.0.0.1:${GITHUB_MOCK_PORT}/repos/python-wheel-build/stevedore-test-repo/tags" \
+  python3 "$MOCK_API_DIR/serve.py" "$GITHUB_MOCK_PORT"
+trap 'python3 -m pip uninstall -y github_override_example >/dev/null 2>&1 || true; on_exit' EXIT
+export GITHUB_API_URL="http://127.0.0.1:${GITHUB_MOCK_PORT}"
+
 # Install the override plugin that routes stevedore through GitHubTagProvider.
-# Uninstall on exit so its entry points don't leak into subsequent e2e tests.
-trap 'python3 -m pip uninstall -y github_override_example >/dev/null 2>&1 || true' EXIT
 pip install "$SCRIPTDIR/github_override_example"
 
 fromager \

pyproject.toml

@@ -185,6 +185,9 @@ ignore = [
     "UP015",  # Unnecessary open mode parameters
 ]
 
+[tool.ruff.lint.per-file-ignores]
+"e2e/github_override_example/mock_api/serve.py" = ["N802"]
+
 [tool.ruff.lint.isort]
 known-first-party = ["fromager"]
 

src/fromager/resolver.py

@@ -1065,15 +1065,14 @@ class GitHubTagProvider(GenericProvider):
     """
 
     provider_description: typing.ClassVar[str] = (
-        "GitHub tag resolver (repository: {self.organization}/{self.repo})"
+        "GitHub tag resolver (repository: {self.server_url} {self.organization}/{self.repo})"
     )
-    host = "github.com:443"
-    api_url = "https://api.{self.host}/repos/{self.organization}/{self.repo}/tags"
 
     def __init__(
         self,
         organization: str,
         repo: str,
+        server_url: str = "https://api.github.com",
         constraints: Constraints | None = None,
         matcher: MatchFunction | re.Pattern | None = None,
         *,
@@ -1092,11 +1091,13 @@ def __init__(
         )
         self.organization = organization
         self.repo = repo
+        self.server_url = server_url.rstrip("/")
+        self.api_url = f"{self.server_url}/repos/{self.organization}/{self.repo}/tags"
         self.override_download_url = override_download_url
 
     @property
     def cache_key(self) -> str:
-        key = f"{self.organization}/{self.repo}"
+        key = f"{self.server_url}/{self.organization}/{self.repo}"
         if self.override_download_url is not None:
             key = f"{key}+{self.override_download_url}"
         return key
@@ -1118,7 +1119,7 @@ def _find_tags(
         if github_token:
             headers["Authorization"] = f"token {github_token}"
 
-        nexturl = self.api_url.format(self=self)
+        nexturl = self.api_url
         while nexturl:
             resp = session.get(nexturl, headers=headers)
             resp.raise_for_status()

tests/test_resolver.py

@@ -100,11 +100,11 @@ def github_fromager_resolver() -> typing.Generator[
 ]:
     with requests_mock.Mocker() as r:
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager",
+            "https://api.github.com/repos/python-wheel-build/fromager",
             text=_github_fromager_repo_response,
         )
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager/tags",
+            "https://api.github.com/repos/python-wheel-build/fromager/tags",
             text=_github_fromager_tag_response,
         )
 
@@ -168,7 +168,7 @@ def test_provider_cache_key_gitlab(gitlab_decile_resolver: typing.Any) -> None:
 
 def test_provider_cache_key_github(github_fromager_resolver: typing.Any) -> None:
     provider = github_fromager_resolver.provider
-    assert provider.cache_key == "python-wheel-build/fromager"
+    assert provider.cache_key == "https://api.github.com/python-wheel-build/fromager"
 
 
 def test_cache_not_overly_aggressive() -> None:
@@ -708,11 +708,11 @@ def test_provider_ignore_platform() -> None:
 def test_resolve_github() -> None:
     with requests_mock.Mocker() as r:
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager",
+            "https://api.github.com/repos/python-wheel-build/fromager",
             text=_github_fromager_repo_response,
         )
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager/tags",
+            "https://api.github.com/repos/python-wheel-build/fromager/tags",
             text=_github_fromager_tag_response,
         )
 
@@ -740,11 +740,11 @@ def test_resolve_github() -> None:
 def test_resolve_github_override_download_url() -> None:
     with requests_mock.Mocker() as r:
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager",
+            "https://api.github.com/repos/python-wheel-build/fromager",
             text=_github_fromager_repo_response,
         )
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager/tags",
+            "https://api.github.com/repos/python-wheel-build/fromager/tags",
             text=_github_fromager_tag_response,
         )
 
@@ -769,11 +769,11 @@ def test_github_constraint_mismatch() -> None:
     constraint.add_constraint("fromager>=1.0")
     with requests_mock.Mocker() as r:
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager",
+            "https://api.github.com/repos/python-wheel-build/fromager",
             text=_github_fromager_repo_response,
         )
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager/tags",
+            "https://api.github.com/repos/python-wheel-build/fromager/tags",
             text=_github_fromager_tag_response,
         )
 
@@ -792,11 +792,11 @@ def test_github_constraint_match() -> None:
     constraint.add_constraint("fromager<0.9")
     with requests_mock.Mocker() as r:
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager",
+            "https://api.github.com/repos/python-wheel-build/fromager",
             text=_github_fromager_repo_response,
         )
         r.get(
-            "https://api.github.com:443/repos/python-wheel-build/fromager/tags",
+            "https://api.github.com/repos/python-wheel-build/fromager/tags",
             text=_github_fromager_tag_response,
         )
 
@@ -1206,7 +1206,7 @@ def test_custom_resolver_error_message_missing_tag() -> None:
     with requests_mock.Mocker() as r:
         # Mock GitHub API to return empty tags (simulating missing tag)
         r.get(
-            "https://api.github.com:443/repos/test-org/test-repo/tags",
+            "https://api.github.com/repos/test-org/test-repo/tags",
             json=[],  # Empty tags list - tag doesn't exist
         )
 
@@ -1244,7 +1244,7 @@ def custom_resolver_provider(
     with requests_mock.Mocker() as r:
         # Mock GitHub API to return empty tags
         r.get(
-            "https://api.github.com:443/repos/test-org/test-repo/tags",
+            "https://api.github.com/repos/test-org/test-repo/tags",
             json=[],
         )