From ae33d1abfbb32bc756ab6313a20eaab6bb98d073 Mon Sep 17 00:00:00 2001 From: claude Date: Tue, 2 Jun 2026 05:26:15 +0000 Subject: [PATCH] =?UTF-8?q?docs(prd):=20revise=20PRD=200031=20=E2=80=94=20?= =?UTF-8?q?provisioned-wins=20merge=20+=20Route=20type=20consolidation?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Expands scope to cover both remaining egress hotspot tasks from #117: - Replaces the named-helper design with a flat provisioned-wins merge (provider routes own their hosts; manifest fills gaps; no upgrade or conflict-detection logic needed). - Adds _route_to_yaml_fields as the single authoritative EgressRoute→Route mapping to prevent silent type drift between host and addon. - Notes that the mitmproxy pure-function split is already clean (decide + is_git_push_request) and requires no structural change. --- docs/prds/0031-split-merge-provider-route.md | 300 ++++++++++++------- 1 file changed, 184 insertions(+), 116 deletions(-) diff --git a/docs/prds/0031-split-merge-provider-route.md b/docs/prds/0031-split-merge-provider-route.md index 3d4c2b6..5d6e008 100644 --- a/docs/prds/0031-split-merge-provider-route.md +++ b/docs/prds/0031-split-merge-provider-route.md @@ -1,4 +1,4 @@ -# PRD 0031: Split `_merge_provider_route` into named case helpers +# PRD 0031: Simplify egress route merge and consolidate Route types - **Status:** Draft - **Author:** didericis-claude @@ -7,167 +7,235 @@ ## Summary -Refactor `_merge_provider_route` in `bot_bottle/egress.py` to replace its -five-outcome nested conditional with a top-level host-lookup dispatch and -one named private function per outcome. No behaviour change. +Replace `_merge_provider_route`'s five-case nested conditional with a +flat provisioned-wins merge, and make the mapping between the host-side +`EgressRoute` and the addon's `Route` explicit in one place. Covers the +two remaining open tasks from the #117 hotspot review. ## Problem -`_merge_provider_route` handles five distinct cases in a single function: +### 1. `_merge_provider_route` branching + +`_merge_provider_route` in `bot_bottle/egress.py` handles five distinct +cases in a single function with interleaved conditions: 1. **append-new** — host not in manifest; append a fresh route. 2. **upgrade-bare** — host found, no existing auth; adopt provider auth. -3. **no-op** — host found, existing auth matches provider auth exactly; - return unchanged. +3. **no-op** — host found, same auth; return unchanged. 4. **tls-passthrough upgrade** — same as no-op but provider sets - `tls_passthrough=True` and the existing route doesn't; flip the flag. -5. **conflict-die** — host found, existing auth differs from provider; - hard error. + `tls_passthrough=True`; flip the flag on the existing route. +5. **conflict-die** — host found, different auth; hard error. -These cases are currently identified by interleaved `if`/`continue` -conditions rather than named dispatch. The control flow is: +Cases 3 and 4 share a block with no-op as the invisible fall-through. +`_find_or_alloc_token_env` is duplicated between cases 2 and 1. In-place +replacements spell out every `EgressRoute` field explicitly, so a new +field added to the dataclass silently drops its value in any replacement +site that wasn't updated. -``` -for idx, route in enumerate(routes): # host lookup - if route.host != pr.host: continue - if route.auth_scheme or route.token_ref: # already-authed branch - if same auth: - if tls upgrade needed: replace # case 4 - return # case 3 - die(...) # case 5 - [token_env alloc] - routes[idx] = ... # case 2 - return routes -[token_env alloc] -routes.append(...) # case 1 -return routes -``` +The root cause of the complexity is that the current merge tries to be +cooperative: it lets manifest routes coexist with provider routes and +attempts to upgrade bare manifest entries. This makes sense if the +manifest is authoritative, but the actual intended hierarchy is the +opposite — provider routes claim their hosts outright and the manifest +fills in what's left. -Specific problems: +### 2. Three-way Route type fragmentation -- Cases 3 and 4 share the same `if same auth:` block; case 3 is the - implicit fall-through after the inner `if`, making it invisible by - name. -- `_find_or_alloc_token_env` is called twice with identical arguments in - the upgrade-bare path (case 2) and the append-new path (case 1). -- Adding a sixth case requires reading the whole function to find the - right insertion point, with no structural hint about case boundaries. -- The in-place index write (`routes[idx] = EgressRoute(...)`) spells out - every field explicitly; a new field added to `EgressRoute` silently - drops its value on any in-place replacement that wasn't updated. +`EgressRoute` (in `egress.py`) and `egress_addon_core.Route` are +separate dataclasses with overlapping but not identical field sets: + +| Field | `EgressRoute` | addon `Route` | +|---|---|---| +| `host` | ✓ | ✓ | +| `path_allowlist` | ✓ | ✓ | +| `auth_scheme` | ✓ | ✓ | +| `token_env` | ✓ | ✓ | +| `token_ref` | ✓ (host-side) | — | +| `roles` | ✓ (host-side) | — | +| `tls_passthrough` | ✓ (pipelock concern) | — | + +`egress_render_routes` serialises `EgressRoute` fields to YAML; the +addon's `load_routes` deserialises that YAML into `Route` objects. If a +field is added to `EgressRoute` that should appear in the YAML, both +`egress_render_routes` and `_parse_one` must be updated consistently. +The render function spells the field list out inline with no reference +to the addon's parser, so divergence is silent until runtime. + +`egress_addon_core.Route` cannot be replaced by `EgressRoute` — the +addon file is copied flat into the sidecar container image (`/app/`) and +has no access to the `bot_bottle` package. The types must stay separate; +the risk is that they drift. ## Goals / Success Criteria -- Each of the five outcomes is implemented in its own named private - function with a docstring stating the precondition. -- `_merge_provider_route` reads as a dispatch table: find the host, then - call the right helper. -- In-place replacements use `dataclasses.replace` instead of full - constructor calls. -- All existing `TestProviderRouteMerge` tests pass without modification. -- No behaviour change. +- `egress_routes_for_bottle` implements a flat provisioned-wins merge: + provider routes claim their hosts; manifest routes for unclaimed hosts + append. No upgrade logic, no conflict detection. +- Token slot assignment is a single pass over the merged list, not + interleaved with the merge. +- `egress_render_routes` uses a single `_route_to_yaml_fields` helper + that explicitly lists the addon-visible fields, creating one place + where the `EgressRoute`→`Route` mapping is spelled out. +- All existing `TestProviderRouteMerge` and `TestRenderRoutes` tests + pass (adjusting assertions for any semantics changes described below). +- No behaviour change for existing manifests that don't trigger the + conflict-die or upgrade-bare paths. ## Non-goals -- Changing the public API of `egress_routes_for_bottle` or - `egress_manifest_routes`. -- Changing merge semantics (what counts as a conflict, what upgrade rules - apply). -- Consolidating any other complexity in `egress.py`. +- Merging `EgressRoute` and `egress_addon_core.Route` into one class + (impossible: addon runs in a stdlib-only container environment). +- Changing what the addon does with a route once it has one. +- Changing `decide()` or `is_git_push_request()` in `egress_addon_core` + — those are already pure functions with good separation. ## Design -### Dispatch structure +### Merge: provisioned wins -```python -def _merge_provider_route( - routes: list[EgressRoute], pr: EgressRoute, -) -> list[EgressRoute]: - for idx, route in enumerate(routes): - if route.host.lower() == pr.host.lower(): - return _merge_at_index(routes, idx, route, pr) - return _append_provider_route(routes, pr) +The new hierarchy: **provisioned routes own their hosts; manifest routes +fill the gaps.** + +``` +provisioned_hosts = {pr.host.lower() for pr in provider_routes} + +effective = list(provider_routes) +effective += [r for r in manifest_routes if r.host.lower() not in provisioned_hosts] ``` -### Per-case helpers - -**`_merge_at_index`** — dispatches on whether the existing route already -carries auth: +Token slot assignment runs as a final pass over `effective` in order: ```python -def _merge_at_index( - routes: list[EgressRoute], idx: int, route: EgressRoute, pr: EgressRoute, -) -> list[EgressRoute]: - if route.auth_scheme or route.token_ref: - return _merge_authed(routes, idx, route, pr) - return _upgrade_bare(routes, idx, route, pr) +def _assign_token_slots( + routes: list[EgressRoute], +) -> tuple[EgressRoute, ...]: + slot_for_ref: dict[str, str] = {} + out: list[EgressRoute] = [] + for r in routes: + if r.auth_scheme and r.token_ref and not r.token_env: + token_env = slot_for_ref.get(r.token_ref) + if token_env is None: + token_env = f"EGRESS_TOKEN_{len(slot_for_ref)}" + slot_for_ref[r.token_ref] = token_env + r = dataclasses.replace(r, token_env=token_env) + out.append(r) + return tuple(out) ``` -**`_merge_authed`** — existing route has auth; either no-op/tls-upgrade -or conflict-die: +This replaces `_merge_provider_route`, `_find_or_alloc_token_env`, and +the slot-assignment loop inside `egress_manifest_routes`. + +#### Semantics change + +Under the old design, a manifest route for a provisioned host with a +*different* `auth_scheme` or `token_ref` raised a hard error. Under +provisioned-wins, the manifest entry is silently dropped. Operators who +relied on the conflict error to catch misconfigurations should audit +their manifests, but in practice this path was only reachable when a +manifest declared auth for `api.openai.com` or `chatgpt.com` with a +token ref other than `CODEX_HOST_CREDENTIAL_TOKEN_REF` while also +enabling `forward_host_credentials` — an unlikely combination. + +Similarly, the "upgrade-bare" path (provider adopts a bare manifest +route's `path_allowlist`) is dropped: a provisioned host takes the +provider route's fields wholesale, and the manifest's `path_allowlist` +for that host is ignored. + +### Route type mapping: `_route_to_yaml_fields` + +Add a pure function in `egress.py`: ```python -def _merge_authed( - routes: list[EgressRoute], idx: int, route: EgressRoute, pr: EgressRoute, -) -> list[EgressRoute]: - """Precondition: route.auth_scheme or route.token_ref is set.""" - if route.auth_scheme != pr.auth_scheme or route.token_ref != pr.token_ref: - die(...) # case 5 - if pr.tls_passthrough and not route.tls_passthrough: - routes[idx] = dataclasses.replace(route, tls_passthrough=True) # case 4 - return routes # case 3 (implicit no-op) +def _route_to_yaml_fields(r: EgressRoute) -> dict: + """Return the addon-visible fields for one route. + + This is the single authoritative mapping between `EgressRoute` + (host-side) and `egress_addon_core.Route` (sidecar-side). If a + field is added to `Route` that must appear in the YAML, add it + here and in `egress_addon_core._parse_one` together.""" + fields: dict = {"host": r.host} + if r.auth_scheme and r.token_env: + fields["auth_scheme"] = r.auth_scheme + fields["token_env"] = r.token_env + if r.path_allowlist: + fields["path_allowlist"] = list(r.path_allowlist) + return fields ``` -**`_upgrade_bare`** — existing route has no auth; adopt provider auth -and preserve `path_allowlist` + `roles`: +`egress_render_routes` delegates to it: ```python -def _upgrade_bare( - routes: list[EgressRoute], idx: int, route: EgressRoute, pr: EgressRoute, -) -> list[EgressRoute]: - """Precondition: route has no auth_scheme or token_ref.""" - token_env = _find_or_alloc_token_env(routes, pr.token_ref) if pr.auth_scheme else "" - routes[idx] = dataclasses.replace( - route, - auth_scheme=pr.auth_scheme, - token_env=token_env, - token_ref=pr.token_ref, - tls_passthrough=pr.tls_passthrough, - ) - return routes +for r in routes: + f = _route_to_yaml_fields(r) + lines.append(f' - host: "{f["host"]}"') + if "auth_scheme" in f: + lines.append(f' auth_scheme: "{f["auth_scheme"]}"') + lines.append(f' token_env: "{f["token_env"]}"') + if "path_allowlist" in f: + lines.append(" path_allowlist:") + for p in f["path_allowlist"]: + lines.append(f' - "{p}"') ``` -**`_append_provider_route`** — host not in manifest; append a new route -(no `path_allowlist` or `roles` to preserve): +The docstring on `_route_to_yaml_fields` is the explicit callout to +update both it and `_parse_one` together when the schema changes. + +### `egress_manifest_routes` / `egress_routes_for_bottle` + +`egress_manifest_routes` becomes a pure lifter with no slot assignment: +it reads each manifest route entry and returns an `EgressRoute` with +`token_env=""` (the slot to be filled later). The function's docstring +currently promises slot assignment; that promise moves to +`egress_routes_for_bottle`. + +`egress_routes_for_bottle` becomes: ```python -def _append_provider_route( - routes: list[EgressRoute], pr: EgressRoute, -) -> list[EgressRoute]: - """Precondition: no existing route matches pr.host.""" - token_env = _find_or_alloc_token_env(routes, pr.token_ref) if pr.auth_scheme else "" - routes.append(dataclasses.replace(pr, token_env=token_env)) - return routes +def egress_routes_for_bottle( + bottle: Bottle, + provider_routes: tuple[EgressRoute, ...] = (), +) -> tuple[EgressRoute, ...]: + manifest = egress_manifest_routes(bottle) + provisioned_hosts = {pr.host.lower() for pr in provider_routes} + merged = list(provider_routes) + [ + r for r in manifest if r.host.lower() not in provisioned_hosts + ] + return _assign_token_slots(merged) ``` -Note: `dataclasses.replace(pr, token_env=token_env)` preserves any -future fields added to `EgressRoute` without requiring updates here. +### Mitmproxy request logic -### Import +`egress_addon_core.decide()` and `is_git_push_request()` are already +pure functions; `egress_addon.EgressAddon.request()` is the minimal +mitmproxy glue (read host/path/headers from flow → call pure functions +→ apply result to flow). This split is already clean and requires no +structural change in this PRD. -Add `import dataclasses` to `egress.py` (currently uses the `dataclass` -decorator from `dataclasses` but not `dataclasses.replace`). +## Test impact + +- **`TestProviderRouteMerge`**: the `test_provider_route_upgrades_bare_manifest_route` + test asserts that a provider route preserves a bare manifest route's + `path_allowlist`. Under provisioned-wins that `path_allowlist` is + dropped. Update the test to reflect the new semantics. +- **`test_provider_route_conflicts_with_different_authed_manifest_route`**: + the conflict-die case no longer exists. Remove this test. +- All other merge and render tests should pass without modification. ## Implementation chunks 1. **PRD (this commit).** Sets the design. -2. **Refactor.** Apply the dispatch + four helpers in `egress.py`; add - `dataclasses` import; delete the old `_merge_provider_route` body. -3. **Tests.** Existing `TestProviderRouteMerge` suite is the acceptance - gate — no new tests needed beyond confirming all pass. +2. **Merge refactor.** Replace `_merge_provider_route` and + `_find_or_alloc_token_env` with `_assign_token_slots` and the + flat provisioned-wins logic in `egress_routes_for_bottle`. Strip + slot assignment from `egress_manifest_routes`. +3. **Render consolidation.** Add `_route_to_yaml_fields`; update + `egress_render_routes` to use it. +4. **Test updates.** Adjust `TestProviderRouteMerge` for the semantics + changes above; confirm all render tests pass. ## References -- Issue #120: Refactor `_merge_provider_route`. -- Issue #117: Complexity hotspots — source of the finding. +- Issue #120: Refactor `_merge_provider_route` (expanded to include + Route type fragmentation). +- Issue #117: Complexity hotspots — source of both findings. - PRD 0030: Deduplicate egress token resolution (prior egress cleanup).