From 2f732457d2af605415b1768a0992db7d9a17c1cf Mon Sep 17 00:00:00 2001 From: pat-s Date: Fri, 7 Aug 2026 14:12:22 +0000 Subject: [PATCH] feat(edge): route PACKAGES requests to the per-R-minor slot (#152) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ## Problem `install.packages("curl")` fails in `reg.devxy.io/r/r-alpine:4.5-3.24` with "package 'curl' is not available for this version of R", on both arches. `curl` is not missing from the repo: it is in `…/latest/src/contrib/4.5/` and `…/4.6/`, the per-minor slots that base R cannot address. The image's repo URL resolves to `…/latest/src/contrib`, whose index does not list it. On `amd64/alpine324` that is 2 886 packages invisible to `install.packages()` (23 on `amd64/noble`) — what issue #63 records as "missing binaries". Two further findings while investigating: - The middleware only ever rewrote the bare `cran.rpkgs.com/src/contrib/…` form, and that form was broken for every Linux client on a stock R user agent: `ALPINE_REGEX`/`UBUNTU_REGEX`/`RHEL_REGEX` need a Posit-style UA that carries the distro, so stock R fell through to `extractOs()` and got redirected to `/amd64/linux-musl/latest/…`, a slot that does not exist. - `PACKAGES*` is served `cdn-cache: BYPASS` (bincraft uploads it `no-store`), so the middleware sees every index request and no purge is needed for routing changes to take effect. ## What this changes **`edge/rpkgs-router.ts`** — the middleware, now a reviewed file in this repo rather than dashboard state. It routes `PACKAGES`, `PACKAGES.gz` and `PACKAGES.rds` into `…/src/contrib//` for slots listed in `UNION_SLOTS`, and nothing else. Tarballs are deliberately left alone. R keeps the `contriburl` it *asked for*, not the one the redirect served it, so every tarball URL is resolved against the flat directory and the union index steers the per-minor ones with a `Path: ` field. Rewriting a tarball request here would send flat-slot packages into a directory that does not hold them. Also in the script: the phantom `linux-gnu`/`linux-musl` fallback is gone (an unidentifiable distro goes to CRAN, as an unparseable UA already did), and every redirect carries `Cache-Control: no-store` since its target depends on the User-Agent. The macOS branches are unchanged. **`cdn.tf`** — `bunnynet_compute_script.rpkgs_router` with `content = file("edge/rpkgs-router.ts")`, the `UNION_SLOTS` variable, and `middleware_script` pointing at the resource instead of the literal `29277`. `UNION_SLOTS` is empty, so merging and applying this changes no client's behaviour. A slot is added only once bincraft has republished its per-minor index as a union (rpkgs/bincraft#97); routing to a raw per-minor index would hide every package it does not carry. Rolling back is a variable edit, not a deploy. **`specs/`, `plans/`** — the design and the implementation plan, including the two approaches that were rejected (edge-side merge, moving the minor up the path) and why. ## Verification `just edge-test` runs 13 routing cases against the SDK's local server, so what is tested is the artifact that gets deployed; pass-through cases proxy to the real origin. All pass. End to end, with the middleware in front of a locally built union index for `amd64/alpine324` (31 507 records), inside the runtime image: ``` curl: 7.1.0 -> …/latest/src/contrib/4.5 -> curl_7.1.0.tar.gz 717 725 B jsonlite: 2.0.0 -> …/latest/src/contrib -> jsonlite_2.0.0.tar.gz 1 055 849 B ``` `tofu validate` passes. `tofu plan` has not been run: no `BUNNYNET_API_KEY` available in this environment. ## Before applying The script pre-dates this configuration, so it must be adopted, not created: ```sh tofu import bunnynet_compute_script.rpkgs_router 29277 tofu plan ``` The plan should show an in-place `content` update and no replacement of the pull zone. Without the import, tofu creates a second script and repoints the zone at it. Note that `name = "rpkgs-router"` will rename the existing script on apply. ## Not fixed here `install.packages("curl")` on `alpine324` will now *resolve*, then fail to build: that slot's tarballs are byte-identical CRAN **source** tarballs (no `Meta/`, no `Built:` in DESCRIPTION) which the index nevertheless stamps `Built: R 4.5.3; …-linux-musl`. Sampled: `amd64/alpine324` 3/12 binary, `arm64/alpine324` 13/30, `amd64/noble` 12/12, `amd64/alpine323` 17/20. That slot needs a rebuild, tracked separately. Reviewed-on: https://git.devxy.io/devxy/build-cran-binaries/pulls/152 --- cdn.tf | 25 +- edge/rpkgs-router.test.ts | 160 ++++++++++++ edge/rpkgs-router.ts | 235 ++++++++++++++++++ justfile | 14 ++ plans/2026-08-07-per-minor-edge-routing.md | 166 +++++++++++++ ...026-08-07-per-minor-edge-routing-design.md | 174 +++++++++++++ 6 files changed, 773 insertions(+), 1 deletion(-) create mode 100644 edge/rpkgs-router.test.ts create mode 100644 edge/rpkgs-router.ts create mode 100644 plans/2026-08-07-per-minor-edge-routing.md create mode 100644 specs/2026-08-07-per-minor-edge-routing-design.md diff --git a/cdn.tf b/cdn.tf index 8a950f5..fe1b25f 100644 --- a/cdn.tf +++ b/cdn.tf @@ -52,6 +52,29 @@ ### cran.rpkgs.com +# The edge middleware that resolves the bare cran.rpkgs.com form to an +# / slot and routes PACKAGES* to the per-R-minor slot. The source of +# truth is edge/rpkgs-router.ts; `tofu apply` publishes a new release. +# +# The script pre-dates this configuration, so it is adopted rather than created: +# tofu import bunnynet_compute_script.rpkgs_router 29277 +resource "bunnynet_compute_script" "rpkgs_router" { + type = "middleware" + name = "rpkgs-router" + content = file("${path.module}/edge/rpkgs-router.ts") +} + +# Slots ("/", comma separated) whose per-minor index bincraft has +# already republished as a union of the per-minor and flat slots. Routing to a +# slot that is not listed here would hide every package the per-minor index does +# not carry, so this stays empty until a slot has been backfilled. +resource "bunnynet_compute_script_variable" "rpkgs_router_union_slots" { + script = bunnynet_compute_script.rpkgs_router.id + name = "UNION_SLOTS" + default_value = "" + required = false +} + resource "bunnynet_pullzone" "cran_rpkgs_com" { name = "cran-rpkgs" @@ -64,7 +87,7 @@ resource "bunnynet_pullzone" "cran_rpkgs_com" { origin { type = "OriginUrl" url = "https://devxy-rpkgs-binaries.s3.eu-central-003.backblazeb2.com" - middleware_script = 29277 + middleware_script = bunnynet_compute_script.rpkgs_router.id } routing { diff --git a/edge/rpkgs-router.test.ts b/edge/rpkgs-router.test.ts new file mode 100644 index 0000000..553185d --- /dev/null +++ b/edge/rpkgs-router.test.ts @@ -0,0 +1,160 @@ +/** + * Routing matrix for `edge/rpkgs-router.ts`. + * + * The script is exercised through the SDK's local server rather than by + * importing its internals, so what is tested is the artifact that gets + * deployed. Requests that the script passes through are proxied to the real + * origin, which keeps the "no redirect" cases honest: they assert that the + * client reached the flat slot, not merely that no `Location` was set. + * + * Run with `just edge-test`. + */ +import { assertEquals } from 'jsr:@std/assert@1'; + +const SCRIPT = new URL('./rpkgs-router.ts', import.meta.url).pathname; +const BASE = 'http://127.0.0.1:8080'; +const UNION_SLOTS = 'amd64/alpine324'; + +const UA_R45_MUSL = 'R (4.5.3 x86_64-pc-linux-musl x86_64 linux-musl)'; +const UA_R46_MUSL = 'R (4.6.0 x86_64-pc-linux-musl x86_64 linux-musl)'; +const UA_R45_ALPINE = 'R/4.5.3 R (4.5.3 x86_64-pc-linux-musl x86_64 linux-musl) Alpine Linux 3.24'; +const UA_R45_DARWIN = 'R (4.5.1 aarch64-apple-darwin20 aarch64 darwin20)'; +const UA_CURL = 'curl/8.0.1'; + +const SLOT = '/amd64/alpine324/latest/src/contrib'; +const OTHER_SLOT = '/amd64/noble/latest/src/contrib'; + +interface Probe { + status: number; + location: string | null; + cacheControl: string | null; +} + +async function probe(path: string, userAgent: string): Promise { + const res = await fetch(BASE + path, { + headers: { 'User-Agent': userAgent }, + redirect: 'manual', + }); + await res.body?.cancel(); + return { + status: res.status, + location: res.headers.get('location'), + cacheControl: res.headers.get('cache-control'), + }; +} + +/** Kill tolerantly: the child has already exited if the script failed to load. */ +async function stopServer(child: Deno.ChildProcess): Promise { + try { + child.kill(); + } catch { + // already gone + } + await child.status; +} + +async function startServer(): Promise { + const child = new Deno.Command(Deno.execPath(), { + args: ['run', '-A', SCRIPT], + env: { UNION_SLOTS }, + stdout: 'null', + stderr: 'inherit', + }).spawn(); + + for (let attempt = 0; attempt < 150; attempt++) { + try { + const res = await fetch(`${BASE}/`, { + headers: { 'User-Agent': UA_CURL }, + redirect: 'manual', + }); + await res.body?.cancel(); + return child; + } catch { + await new Promise((resolve) => setTimeout(resolve, 200)); + } + } + + await stopServer(child); + throw new Error('edge script did not start listening on ' + BASE); +} + +Deno.test('rpkgs-router', async (t) => { + const server = await startServer(); + + try { + await t.step("routes an index request to the client's R minor", async () => { + const res = await probe(`${SLOT}/PACKAGES.gz`, UA_R45_MUSL); + assertEquals(res.status, 302); + assertEquals(res.location, `https://cran.rpkgs.com${SLOT}/4.5/PACKAGES.gz`); + }); + + await t.step('routes R 4.6 to its own slot', async () => { + const res = await probe(`${SLOT}/PACKAGES.gz`, UA_R46_MUSL); + assertEquals(res.location, `https://cran.rpkgs.com${SLOT}/4.6/PACKAGES.gz`); + }); + + await t.step('routes PACKAGES and PACKAGES.rds too', async () => { + for (const file of ['PACKAGES', 'PACKAGES.rds']) { + const res = await probe(`${SLOT}/${file}`, UA_R45_MUSL); + assertEquals(res.location, `https://cran.rpkgs.com${SLOT}/4.5/${file}`, `expected ${file} to be routed`); + } + }); + + await t.step('marks the redirect uncacheable', async () => { + const res = await probe(`${SLOT}/PACKAGES.gz`, UA_R45_MUSL); + assertEquals(res.cacheControl, 'no-store'); + }); + + await t.step('leaves a slot outside UNION_SLOTS alone', async () => { + const res = await probe(`${OTHER_SLOT}/PACKAGES.gz`, UA_R45_MUSL); + assertEquals(res.location, null); + assertEquals(res.status, 200); + }); + + await t.step('never routes a tarball', async () => { + const res = await probe(`${SLOT}/jsonlite_2.0.0.tar.gz`, UA_R45_MUSL); + assertEquals(res.location, null); + assertEquals(res.status, 200); + }); + + await t.step('does not redirect a path already under a minor', async () => { + const res = await probe(`${SLOT}/4.5/PACKAGES.gz`, UA_R45_MUSL); + assertEquals(res.location, null); + assertEquals(res.status, 200); + }); + + await t.step('leaves a client without an R version alone', async () => { + const res = await probe(`${SLOT}/PACKAGES.gz`, UA_CURL); + assertEquals(res.location, null); + assertEquals(res.status, 200); + }); + + await t.step('resolves the bare root to slot and minor', async () => { + const res = await probe('/src/contrib/PACKAGES.gz', UA_R45_ALPINE); + assertEquals(res.location, `https://cran.rpkgs.com${SLOT}/4.5/PACKAGES.gz`); + }); + + await t.step('sends an unidentifiable distro to CRAN', async () => { + const res = await probe('/src/contrib/PACKAGES.gz', UA_R45_MUSL); + assertEquals(res.location, 'https://cran.r-project.org/src/contrib/PACKAGES.gz'); + }); + + await t.step('keeps the macOS rewrite', async () => { + const res = await probe('/src/contrib/foo_1.0.tar.gz', UA_R45_DARWIN); + assertEquals(res.location, 'https://cran.rpkgs.com/bin/macosx/big-sur-arm64/contrib/4.5/foo_1.0.tar.gz'); + }); + + await t.step('keeps the macOS binary passthrough to CRAN', async () => { + const path = '/bin/macosx/big-sur-arm64/contrib/4.5/foo_1.0.tar.gz'; + const res = await probe(path, UA_R45_DARWIN); + assertEquals(res.location, `https://cran.r-project.org${path}`); + }); + + await t.step('collapses duplicate slashes before matching', async () => { + const res = await probe(`/amd64/alpine324//latest/src/contrib//PACKAGES.gz`, UA_R45_MUSL); + assertEquals(res.location, `https://cran.rpkgs.com${SLOT}/4.5/PACKAGES.gz`); + }); + } finally { + await stopServer(server); + } +}); diff --git a/edge/rpkgs-router.ts b/edge/rpkgs-router.ts new file mode 100644 index 0000000..9cd410b --- /dev/null +++ b/edge/rpkgs-router.ts @@ -0,0 +1,235 @@ +/** + * Edge middleware for cran.rpkgs.com. + * + * Two jobs: + * + * 1. Resolve the bare `https://cran.rpkgs.com` form to a concrete + * `/` slot from the User-Agent, or send the client to CRAN when + * the distro cannot be identified. + * 2. Route `PACKAGES*` requests to the per-R-minor slot + * (`…/latest/src/contrib//`), so a stock `install.packages()` sees the + * packages that only exist there. + * + * Only index files are routed. Tarballs are deliberately left alone: R keeps + * the contrib URL it asked for, not the one it was redirected to, so every + * tarball URL is resolved against the flat directory and the union index steers + * the per-minor ones with a `Path: ` field. Rewriting a tarball request + * here would send flat-slot packages into a directory that does not hold them. + * + * Routing is gated on UNION_SLOTS. The raw per-minor index holds only the + * ABI-sensitive subset of a slot; it is safe to route to it only once bincraft + * has republished it as a union of the per-minor and flat slots. + * + * Deployed by OpenTofu from this file (`bunnynet_compute_script.rpkgs_router`). + * Test with `just edge-test`. + */ +import * as BunnySDK from 'https://esm.sh/@bunny.net/edgescript-sdk@0.12'; + +const PUBLIC_CDN_ORIGIN = 'https://cran.rpkgs.com'; +const CRAN_ORIGIN = 'https://cran.r-project.org'; + +/** Slots ("/", comma separated) whose per-minor index is a union. */ +const UNION_SLOTS = new Set( + (Deno.env.get('UNION_SLOTS') ?? '') + .split(',') + .map((slot) => slot.trim()) + .filter((slot) => slot.length > 0), +); + +/** `///latest/src/contrib[/]` */ +const SLOT_PATH_REGEX = /^\/(amd64|arm64)\/([a-z0-9._-]+)\/latest\/src\/contrib\/?(.*)$/; + +/** A path that already sits in a per-minor slot, e.g. `4.5/PACKAGES.gz`. */ +const MINOR_DIR_REGEX = /^\d+\.\d+\//; + +/** The only files this script routes. */ +const INDEX_FILE_REGEX = /^PACKAGES(\.gz|\.rds)?$/; + +const SRC_CONTRIB_REGEX = /^\/src\/contrib\/(.+)$/; + +const MACOS_BIN_REGEX = + /^\/bin\/macosx\/(big-sur-arm64|big-sur-x86_64|monterey-arm64|monterey-x86_64)\/contrib\/([0-9.]+)\/(.+)$/; + +const RHEL_REGEX = /(almalinux|rocky)[^\d]*(\d+)/i; + +const UBUNTU_REGEX = /Ubuntu ([\d.]+)/i; +const UBUNTU_CODENAMES: Record = { + '24.04': 'noble', + '22.04': 'jammy', +}; + +const ALPINE_REGEX = /(?:Alpine Linux(?:\s+VERSION_ID=)?|alpine-)\s*(\d+)\.(\d+)/i; + +/** + * R's own User-Agent is `R (4.5.3 x86_64-pc-linux-musl …)`; the Posit-style one + * some sites configure is `R/4.5.3 R (…)`. Both carry the minor, which is why + * per-minor routing works without the distro being identifiable. + */ +const R_MINOR_REGEXES = [/\bR\/(\d+)\.(\d+)/, /\bR \((\d+)\.(\d+)/]; + +function normalizePathname(pathname: string): string { + return pathname.replace(/\/{2,}/g, '/'); +} + +function redirectTo(location: string, status = 302): Response { + return new Response(null, { + status, + headers: { + Location: location, + // The target depends on the User-Agent, so the redirect itself must + // never be cached; only its target is a cacheable, UA-independent URL. + 'Cache-Control': 'no-store', + 'X-Via': 'MyMiddleware', + 'X-Rewritten-By': 'rpkgs-edge-middleware', + }, + }); +} + +function extractRMinor(userAgent: string): string | null { + for (const regex of R_MINOR_REGEXES) { + const match = userAgent.match(regex); + if (match) { + return `${match[1]}.${match[2]}`; + } + } + return null; +} + +function mapArch(arch: string): string { + if (arch === 'aarch64') return 'arm64'; + if (arch === 'x86_64') return 'amd64'; + return arch; +} + +function extractArch(userAgent: string): string { + const match = userAgent.match(/(x86_64|aarch64|arm64|i386|i686)/); + return match ? mapArch(match[1]) : ''; +} + +/** + * Identify the `/` slot from the User-Agent, or null. + * + * A stock R User-Agent carries only `linux-gnu` / `linux-musl`, which are not + * slot names: returning them produced redirects into slots that do not exist + * (`/amd64/linux-musl/latest/…`, a guaranteed 404). An unidentifiable distro + * is reported as such so the caller can fall back to CRAN. + */ +function parseSlot(userAgent: string): string | null { + const arch = extractArch(userAgent); + if (!arch) { + return null; + } + + const rhel = userAgent.match(RHEL_REGEX); + if (rhel) { + return `${arch}/rhel${rhel[2]}`; + } + + const ubuntu = userAgent.match(UBUNTU_REGEX); + if (ubuntu) { + const codename = UBUNTU_CODENAMES[ubuntu[1]]; + if (codename) { + return `${arch}/${codename}`; + } + } + + const alpine = userAgent.match(ALPINE_REGEX); + if (alpine) { + return `${arch}/alpine${alpine[1]}${alpine[2]}`; + } + + return null; +} + +function parseMacUserAgent(userAgent: string): { os: string; arch: string; rver: string } | null { + const rverMatch = userAgent.match(/R \((\d+)\.(\d+)/); + const archMatch = userAgent.match(/(aarch64|arm64|x86_64)/); + const osMatch = userAgent.match(/darwin(\d+)/); + + if (!rverMatch || !archMatch || !osMatch) { + return null; + } + + const arch = archMatch[1] === 'aarch64' ? 'arm64' : archMatch[1]; + const darwinVer = parseInt(osMatch[1], 10); + const os = darwinVer >= 21 && darwinVer < 22 ? `monterey-${arch}` : `big-sur-${arch}`; + + return { os, arch, rver: `${rverMatch[1]}.${rverMatch[2]}` }; +} + +/** + * The contrib path a request should be served from, relative to the slot. + * + * Returns the per-minor path for an index file when the slot is known to carry + * a union index and the client's R minor is known; otherwise the flat path, + * which is what every client sees today. + */ +function contribPath(slot: string, rest: string, userAgent: string): string { + const flat = rest ? `/${slot}/latest/src/contrib/${rest}` : `/${slot}/latest/src/contrib`; + + if (!INDEX_FILE_REGEX.test(rest) || !UNION_SLOTS.has(slot)) { + return flat; + } + + const rMinor = extractRMinor(userAgent); + return rMinor ? `/${slot}/latest/src/contrib/${rMinor}/${rest}` : flat; +} + +BunnySDK.net.http + .servePullZone({ url: 'https://cran.rpkgs.com/' }) + .onOriginRequest((ctx) => { + const url = new URL(ctx.request.url); + const path = normalizePathname(url.pathname); + const userAgent = ctx.request.headers.get('User-Agent') || ''; + + // macOS clients are served from CRAN's own binary tree. + const srcContrib = path.match(SRC_CONTRIB_REGEX); + if (srcContrib && /darwin/.test(userAgent)) { + const mac = parseMacUserAgent(userAgent); + if (mac) { + return Promise.resolve( + redirectTo(`${PUBLIC_CDN_ORIGIN}/bin/macosx/${mac.os}/contrib/${mac.rver}/${srcContrib[1]}`), + ); + } + } + + if (MACOS_BIN_REGEX.test(path)) { + return Promise.resolve(redirectTo(`${CRAN_ORIGIN}${path}`)); + } + + // Already-qualified slot URLs: what the runtime images have baked in. + const slotPath = path.match(SLOT_PATH_REGEX); + if (slotPath) { + const slot = `${slotPath[1]}/${slotPath[2]}`; + const rest = slotPath[3]; + + // Never rewrite a request that is already in a per-minor slot, or the + // redirect would chase its own tail. + if (MINOR_DIR_REGEX.test(rest)) { + return Promise.resolve(ctx.request); + } + + const target = contribPath(slot, rest, userAgent); + if (target === path) { + return Promise.resolve(ctx.request); + } + return Promise.resolve(redirectTo(`${PUBLIC_CDN_ORIGIN}${target}`)); + } + + // The bare `https://cran.rpkgs.com` form, resolved from the User-Agent. + if (path === '/' || path === '/src/contrib' || path.startsWith('/src/contrib/')) { + const slot = parseSlot(userAgent); + if (!slot) { + return Promise.resolve(redirectTo(`${CRAN_ORIGIN}${path}`)); + } + + const rest = srcContrib ? srcContrib[1] : ''; + return Promise.resolve(redirectTo(`${PUBLIC_CDN_ORIGIN}${contribPath(slot, rest, userAgent)}`)); + } + + return Promise.resolve(ctx.request); + }) + .onOriginResponse((ctx) => { + ctx.response.headers.append('X-Via', 'MyMiddleware'); + return Promise.resolve(ctx.response); + }); diff --git a/justfile b/justfile index a9a705e..6c75b13 100644 --- a/justfile +++ b/justfile @@ -73,3 +73,17 @@ rebuild os tag arch package *versions: --build-arg CACHEBUST="$(date +%s)" \ -f docker/build-one.Dockerfile \ local + +# run the edge middleware routing matrix (uses a local deno, else the deno image) +edge-test: + #!/usr/bin/env bash + set -euo pipefail + if command -v deno >/dev/null 2>&1; then + deno test -A edge/rpkgs-router.test.ts + else + docker run --rm \ + -v "$PWD:/w" -w /w \ + -v deno-cache:/deno-dir \ + denoland/deno:latest \ + deno test -A edge/rpkgs-router.test.ts + fi diff --git a/plans/2026-08-07-per-minor-edge-routing.md b/plans/2026-08-07-per-minor-edge-routing.md new file mode 100644 index 0000000..3c3e320 --- /dev/null +++ b/plans/2026-08-07-per-minor-edge-routing.md @@ -0,0 +1,166 @@ +# Per-R-minor edge routing implementation plan + +Spec: `specs/2026-08-07-per-minor-edge-routing-design.md` + +**Goal:** let a stock `install.packages()` see the per-minor packages by routing `PACKAGES*` requests to `…/src/contrib//`, where `bincraft` publishes a union index. + +**Architecture:** the union is built in `bincraft`; the edge script only redirects index requests, gated on a `UNION_SLOTS` script variable; the script lives in this repo and is applied by OpenTofu. + +**Tech stack:** Deno / TypeScript (Bunny Edge Scripting, SDK 0.12), OpenTofu with `BunnyWay/bunnynet` 0.17, R (bincraft). + +## Global constraints + +- Redirect only `PACKAGES`, `PACKAGES.gz` and `PACKAGES.rds`; never a tarball, because the union index already carries the correct tarball URL for both classes of package. +- Every redirect carries `Cache-Control: no-store`; redirect targets stay UA-independent. +- `UNION_SLOTS` is empty by default, so deploying the script is a no-op until a slot is backfilled. +- A slot is `/`, e.g. `amd64/alpine324`. +- Verified prerequisites: `PACKAGES*` is served `cdn-cache: BYPASS`, so the script sees every index request; `Deno.env.get()` reads script variables; the SDK local server listens on `127.0.0.1:8080`. + +--- + +## Task 1: Edge script and its test matrix + +**Files:** + +- Create: `edge/rpkgs-router.ts` +- Create: `edge/rpkgs-router.test.ts` +- Modify: `justfile` (add `edge-test`) + +**Produces:** a single-file script deployable as `bunnynet_compute_script.content`, reading `UNION_SLOTS` from the environment. + +- [ ] **Step 1: write the test matrix first** + +`edge/rpkgs-router.test.ts` spawns `deno run -A edge/rpkgs-router.ts` with `UNION_SLOTS=amd64/alpine324`, waits for `127.0.0.1:8080`, and issues requests with `redirect: "manual"`. + +Cases, asserted on the `location` header (or its absence): + +| # | path | User-Agent | expectation | +| --- | ------------------------------------------------------ | --------------------------------------------- | ------------------------------------------------------------ | +| 1 | `/amd64/alpine324/latest/src/contrib/PACKAGES.gz` | `R (4.5.3 x86_64-pc-linux-musl …)` | 302 → `…/src/contrib/4.5/PACKAGES.gz` | +| 2 | same | `R (4.6.0 …)` | 302 → `…/src/contrib/4.6/PACKAGES.gz` | +| 3 | same, but slot `amd64/noble` | `R (4.5.3 …)` | no redirect (slot not in `UNION_SLOTS`) | +| 4 | `…/src/contrib/curl_7.1.0.tar.gz` | `R (4.5.3 …)` | no redirect | +| 5 | `…/src/contrib/4.5/PACKAGES.gz` | `R (4.5.3 …)` | no redirect (loop guard) | +| 6 | `…/src/contrib/PACKAGES.gz` | `curl/8.0` | no redirect (no R minor) | +| 7 | `/src/contrib/PACKAGES.gz` | alpine UA with `Alpine Linux … 3.24` | 302 → `/amd64/alpine324/latest/src/contrib/4.5/PACKAGES.gz` | +| 8 | `/src/contrib/PACKAGES.gz` | `R (4.5.3 x86_64-pc-linux-musl …)`, no distro | 302 → `cran.r-project.org`, **not** a `linux-musl` slot | +| 9 | `/src/contrib/foo_1.0.tar.gz` | `R (4.5.1 aarch64-apple-darwin20 …)` | 302 → `/bin/macosx/big-sur-arm64/contrib/4.5/foo_1.0.tar.gz` | +| 10 | `/bin/macosx/big-sur-arm64/contrib/4.5/foo_1.0.tar.gz` | any | 302 → `cran.r-project.org` | +| 11 | any redirect above | — | `cache-control: no-store` | + +- [ ] **Step 2: run the tests and watch them fail** + +`just edge-test` → every case fails, because `edge/rpkgs-router.ts` does not exist. + +- [ ] **Step 3: write `edge/rpkgs-router.ts`** + +Order of evaluation in `onOriginRequest`: + +1. normalise `//` runs in the path +2. darwin `/src/contrib/*` → `/bin/macosx//contrib//` +3. `/bin/macosx/**` → CRAN +4. `/{arch}/{os}/latest/src/contrib/`: pass through if `rest` already starts with `/`, or is not an index file, or the slot is not in `UNION_SLOTS`, or the UA has no R minor; otherwise redirect into `/` +5. `/`, `/src/contrib`, `/src/contrib/**`: resolve arch+os from the UA, redirect to CRAN when the distro is unidentifiable, otherwise redirect to the qualified path, adding `/` under the same index-file rule +6. anything else: pass through + +The R minor comes from either `R/4.5.3` or `R (4.5.3 …)`, so a stock UA is enough. The `linux-gnu` / `linux-musl` fallback in `parseUserAgent` is deleted: those are not slot names. + +- [ ] **Step 4: run the tests until they pass** + +`just edge-test` + +- [ ] **Step 5: commit** + +```bash +git add edge/rpkgs-router.ts edge/rpkgs-router.test.ts justfile +git commit -m "feat(edge): route PACKAGES requests to the per-R-minor slot" +``` + +--- + +## Task 2: Manage the script from OpenTofu + +**Files:** + +- Modify: `cdn.tf` + +**Consumes:** `edge/rpkgs-router.ts` from Task 1. + +- [ ] **Step 1: add the resources** + +```terraform +resource "bunnynet_compute_script" "rpkgs_router" { + type = "middleware" + name = "rpkgs-router" + content = file("${path.module}/edge/rpkgs-router.ts") +} + +resource "bunnynet_compute_script_variable" "rpkgs_router_union_slots" { + script = bunnynet_compute_script.rpkgs_router.id + name = "UNION_SLOTS" + default_value = "" + required = false +} +``` + +and replace `middleware_script = 29277` with `middleware_script = bunnynet_compute_script.rpkgs_router.id`. + +- [ ] **Step 2: validate** + +`tofu init -backend=false && tofu validate` + +- [ ] **Step 3: import the existing script (needs `BUNNYNET_API_KEY`)** + +```bash +tofu import bunnynet_compute_script.rpkgs_router 29277 +tofu plan +``` + +The plan must show an in-place `content` update and **no** replacement of the pull zone. A replacement means the import did not take. + +- [ ] **Step 4: commit** + +```bash +git add cdn.tf +git commit -m "feat(cdn): manage the edge middleware script from this repo" +``` + +--- + +## Task 3: Union index writer in bincraft + +**Files (repo `codefloe.com/rpkgs/bincraft`):** + +- Modify: `R/package_index.R` +- Test: `tests/testthat/test-package_index.R` + +**Produces:** `write_union_index(flat_records, minor_records)` returning the merged records, called from `upload_package_index()` when `r_minor` is set. + +- [ ] **Step 1: write the failing tests** + +- a package present in both slots keeps the per-minor record, with `Path = "4.5"` +- a package only in the flat slot survives with no `Path` +- a package only in the per-minor slot survives with `Path = "4.5"` +- a union smaller than the flat input raises an error rather than returning + +- [ ] **Step 2: run them and watch them fail** + +`Rscript -e 'testthat::test_file("tests/testthat/test-package_index.R")'` + +- [ ] **Step 3: implement `write_union_index()` and call it from `upload_package_index()`** + +After `update_PACKAGES()` has written the per-minor index, read the flat slot's `PACKAGES.rds`, set `Path = ` on the per-minor records, drop the flat records for packages the per-minor slot already has, and rewrite `PACKAGES`, `PACKAGES.gz` and `PACKAGES.rds` in the per-minor slot. + +- [ ] **Step 4: run the tests until they pass** + +- [ ] **Step 5: commit and open the PR against bincraft** + +--- + +## Task 4: Roll out slot by slot + +- [ ] Re-index one slot (`amd64/alpine324`, R 4.5) and confirm the union index lists both `curl` (per-minor, `Path: 4.5`) and `jsonlite` (flat, no `Path`). +- [ ] Set `UNION_SLOTS = "amd64/alpine324"` and confirm in `reg.devxy.io/r/r-alpine:4.5-3.24` that `available.packages()` returns the union count and `"curl" %in% rownames(...)`. +- [ ] Add `arm64/alpine324`, then the remaining slots. + +`install.packages("curl")` will still fail to build on `alpine324` until that slot's source tarballs are replaced with real binaries. That is tracked separately. diff --git a/specs/2026-08-07-per-minor-edge-routing-design.md b/specs/2026-08-07-per-minor-edge-routing-design.md new file mode 100644 index 0000000..b55812c --- /dev/null +++ b/specs/2026-08-07-per-minor-edge-routing-design.md @@ -0,0 +1,174 @@ +# Design: Routing clients to per-R-minor binary slots + +Date: 2026-08-07 +Status: Approved (pending spec review) + +## Problem + +`bincraft` routes ABI-"risky" packages to a per-minor slot `…/latest/src/contrib//` and indexes every directory independently (`upload_package_index()` calls `cranlike::update_PACKAGES()` on one prefix at a time). +Nothing unions those indices, and `contrib.url()` only ever yields `/src/contrib`, so no value of `options(repos)` can address a per-minor slot. +Only `uvr` resolves per-minor URLs, which means the per-minor slots are invisible to `install.packages()` by construction. + +Measured on 2026-08-07: + +| slot | flat `src/contrib` | `src/contrib/4.5` | unique packages only in the per-minor slot | +| ----------------- | ------------------ | ----------------- | ------------------------------------------ | +| `amd64/alpine324` | 21 640 | 3 310 | 2 886 | +| `amd64/noble` | 24 495 | 398 | 23 | + +This is what issue #63 records as "missing binaries" on `alpine324`. +The packages are not missing; they are in a directory base R cannot reach. +The user-visible symptom in `reg.devxy.io/r/r-alpine:4.5-3.24` is: + +``` +> install.packages("curl") +Warning message: +package 'curl' is not available for this version of R +``` + +A second, unrelated defect exists on the same slot and is **out of scope here**: many `alpine324` tarballs are byte-identical CRAN _source_ tarballs that the index nevertheless stamps `Built: R 4.5.3; …-linux-musl`. +Routing exposes `curl`; only a rebuild of that slot makes it install. + +## Goal + +Let a stock `install.packages()` see one complete package list for its own R minor, without duplicating tarballs and without an R-version-varying cache key anywhere in the CDN. + +## Key constraint that drives the design + +R resolves a package's download URL from the index, not from the request path, and it keeps the `contriburl` it _asked for_ rather than the one it was redirected to. +Measured with `options(repos = …/latest)` against a middleware that redirects the index into `4.5/`: + +``` +curl available: TRUE +curl repo: …/latest/src/contrib # the flat URL, not the 4.5 one it was served from +``` + +So the union index is always addressed relative to the **flat** directory, whatever path it was fetched from. +`available.packages()` honours a `Path:` field and folds it into the `Repository` column, which gives the whole routing for free: + +- a per-minor record carries `Path: `, so its tarball is fetched from `…/src/contrib//` +- a flat record carries no `Path`, so its tarball is fetched from `…/src/contrib/` + +Verified end to end against the live CDN with a locally built union index for `amd64/alpine324` (31 507 records): + +``` +curl: 7.1.0 -> …/latest/src/contrib/4.5 -> curl_7.1.0.tar.gz 717 725 B +jsonlite: 2.0.0 -> …/latest/src/contrib -> jsonlite_2.0.0.tar.gz 1 055 849 B +``` + +The corollary is that the edge script must **not** rewrite tarball requests: every tarball URL is already correct when it leaves the client, and redirecting one into `/` would break exactly the flat packages the union is meant to preserve. + +The complementary trick does not work: R's `gzcon()` reads only the first member of a concatenated gzip stream (10 291 of an expected 31 931 records), so an edge-side merge would have to fully decompress and recompress both indices and additionally 404 `PACKAGES.rds` to stop R preferring it. +That is why the union is produced in `bincraft`, not at the edge. + +## Approaches considered + +| Approach | Where the union lives | Verdict | +| ----------------------------------------------------------- | ------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------- | +| **A. Union index written by `bincraft` (chosen)** | per-minor `PACKAGES*`, per-minor entries carry `Path: ` | Edge does one redirect; `PACKAGES.rds` stays correct; no duplication | +| B. Merge at the edge | middleware fetches both indices, recompresses | ~2 MB decompress/recompress per cache fill, cache key must include the R minor, breaks R's `.rds` fast path | +| C. Move the minor up the path (`latest//src/contrib/`) | addressable by `options(repos)` directly | No edge logic at all, but a full layout migration and breaks the published URL contract | + +Chosen: **A**. + +## Architecture + +### bincraft: union index (separate PR) + +After writing a per-minor index, republish it as a union of that slot and the flat slot: + +1. Read the flat slot's `PACKAGES.rds` and the per-minor slot's own records. +2. Set `Path: ` on every per-minor record, so its tarball resolves into the per-minor directory. +3. Drop every flat record whose package is already present in the per-minor slot, so the per-minor build always wins, and leave the survivors without a `Path`. +4. Write the merged `PACKAGES`, `PACKAGES.gz` and `PACKAGES.rds` into `…/src/contrib//`. + +Guard: refuse to publish a union with fewer records than the flat index it was built from. +A truncated union is worse than no union, because it silently removes packages from every client on that minor. + +### Edge script (this repo) + +The script routes `PACKAGES`, `PACKAGES.gz` and `PACKAGES.rds` requests, and nothing else. + +``` +normalize path +parseClient(UA) -> { rMinor, arch, os } # rMinor from "R (4.5.3 …)" or "R/4.5.3" +darwin branches # unchanged +if path is /{arch}/{os}/latest/src/contrib/PACKAGES* + already under // ? pass through # loop guard + rMinor known && slot in UNION_SLOTS ? 302 -> …/src/contrib//PACKAGES* + else pass through # flat slot, today's behaviour +if path is /src/contrib/… # bare root + resolve arch + os; unknown -> 302 to CRAN + then apply the same PACKAGES* rule +else pass through +``` + +Redirects carry `Cache-Control: no-store`. +Every cacheable URL is therefore UA-independent, and no cache key has to vary by R version. + +### Repaired bare-root detection + +The bare `https://cran.rpkgs.com` form is currently broken for every Linux client that uses a stock R user agent. +`ALPINE_REGEX`, `UBUNTU_REGEX` and `RHEL_REGEX` only match a Posit-style user agent the user has to set by hand; stock R never carries the distro, so the script falls through to `extractOs()` and redirects to a slot that does not exist: + +``` +UA: R (4.5.3 x86_64-pc-linux-musl …) -> 302 /amd64/linux-musl/latest/… (404) +UA: R (4.5.3 x86_64-pc-linux-gnu …) -> 302 /amd64/linux-gnu/latest/… (404) +``` + +The fallback to a phantom `linux-musl` / `linux-gnu` slot is removed. +An unidentifiable distro redirects to CRAN, which is the existing behaviour for an unparseable user agent. +The R _minor_ is always present in a stock user agent, so per-minor routing itself does not depend on distro detection. + +### Rollout gate + +`UNION_SLOTS` is a `bunnynet_compute_script_variable` listing the slots whose per-minor index is already a union. +It is empty by default, so deploying the script changes nothing until `bincraft` has backfilled a slot, and a rollback is a variable edit rather than a code deploy. +All slots currently carry `4.4`, `4.5` and `4.6`; a client on any other minor falls through to the flat slot. + +### Deployment from this repo + +The script is a file in the repo, applied by the existing OpenTofu configuration: + +``` +edge/rpkgs-router.ts # the script +edge/rpkgs-router.test.ts # UA x path -> expected Location matrix +cdn.tf # bunnynet_compute_script + _variable +``` + +Provider `BunnyWay/bunnynet` v0.17.0 (already pinned) ships `bunnynet_compute_script` with `content` loadable via `file()`, plus `bunnynet_compute_script_variable`. +`middleware_script = bunnynet_compute_script.rpkgs_router.id` replaces the hard-coded `29277`, after a one-time `tofu import` of the existing script. + +## Error handling + +- Unknown R minor, or a slot not listed in `UNION_SLOTS`: pass through to the flat slot. + The client sees exactly today's behaviour. +- Unparseable distro on the bare-root form: redirect to CRAN. +- A request already under `…/src/contrib//`: pass through, so a redirect can never loop. +- A per-minor slot that does not exist for a listed minor: the client gets the origin's 404. + `UNION_SLOTS` is the operator's assertion that the slot is ready, so this is a configuration error, not a runtime condition to paper over. + +## Testing + +Local, before any apply: `deno run -A edge/rpkgs-router.ts` serves the middleware against the real origin, so `edge/rpkgs-router.test.ts` drives the whole matrix against that local server. + +- User agent matrix: R 4.4 / 4.5 / 4.6 on musl and gnu, both arches, Posit-style and stock forms, plus a darwin UA and a non-R UA. +- Path matrix: `PACKAGES`, `PACKAGES.gz`, `PACKAGES.rds`, a tarball, a path already under `4.5/`, and `/src/contrib/…` on the bare root. +- Assertion is the `Location` header (or its absence), not the body. + +After apply, a smoke test against `cran.rpkgs.com`: + +- `available.packages()` inside `reg.devxy.io/r/r-alpine:4.5-3.24` returns the union count, and `"curl" %in% rownames(...)` is `TRUE`. +- A flat-slot package still downloads from `…/src/contrib/`, and a per-minor package downloads from `…/src/contrib//`. + +## Out of scope + +- `Meta/archive.rds` stays flat-only, so `remotes::install_version()` does not see per-minor archives. +- The `alpine324` source-tarball defect: that slot serves CRAN sources stamped as binaries, and needs a rebuild independent of this work. +- Any change to how `uvr` resolves per-minor URLs; it already addresses the slots directly. + +## Split of work + +1. `bincraft`: union index writer plus its guard, and a re-index of one slot to validate. +2. This repo: `edge/rpkgs-router.ts`, its test matrix, and the `cdn.tf` resources with `UNION_SLOTS` empty. +3. Enable `UNION_SLOTS` slot by slot as `bincraft` backfills them.