# 2026-05-15 — Universe Onboarding PR1

Resumed `/plans/universe-onboarding.md` at PR1 (Broker config foundations: `WorldConfig.PublicURL`).

## Changes

- `tools/demarkus-broker/internal/broker/config.go` — added `WorldConfig.PublicURL string` with a doc comment explaining the field belongs on the broker (single source of truth for the client-facing address), is optional, and that a blank value means "skip in /me/install."
- `deploy/helm/demarkus-broker/values.yaml` — documented `publicURL` in the commented worlds[] example with the rationale for setting it.
- `deploy/helm/demarkus-broker/templates/secret-config.yaml` — render `publicURL: "<value-or-empty>"` for every world. Always emitted so the YAML shape is stable across set/unset, and operators can grep for the field.
- `tools/demarkus-broker/internal/broker/config_test.go` — two new subtests: empty default round-trip + explicit `mark://` value round-trip.
- `deploy/helm/demarkus-broker/tests/secret-config_test.yaml` — two new cases: blank renders as `publicURL: ""`, operator-supplied value renders verbatim.

## Verification

- `go test ./internal/broker/ -run TestLoadConfig` → 29/29 pass (2 new).
- `helm unittest -f tests/secret-config_test.yaml .` → 13/13 pass (2 new).
- `bash pre-commit.sh` → format, vet, lint clean across protocol/server/client/tools.

## Scope discipline

No validation in PR1 — plan calls for "optional; validation only requires it when used." Shape validation (`mark://` URL, port present, etc.) lives with the `/me/install` consumer in PR5.

`KnownFields(true)` means older broker binaries would reject the new chart's rendered config because of the unknown `publicURL` line. Chart appVersion gates broker upgrade as usual; not new for this PR.

## Next

PR2 — broker discovery doc (`GET /.well-known/openid-configuration` proxying the IdP discovery with device-endpoint overrides). Resume at `tools/demarkus-broker/internal/broker/discovery.go` (new file) + route registration in `server.go`.

Pending review: should PR1 ship as a standalone PR or be folded into PR2? Plan calls for independent reviewability per PR, so default is standalone.


## PR2 — Broker discovery doc

PR1 (#135) merged. Continuing through plan PR2: broker-hosted `/.well-known/openid-configuration` that proxies the IdP's discovery doc with broker-hosted endpoint overrides.

### Changes

- `tools/demarkus-broker/internal/broker/discovery.go` (new) — `Discovery` type. Fetches `<idpIssuer>/.well-known/openid-configuration` once at `NewDiscovery`, parses into `map[string]any` so unknown fields proxy through unchanged, rewrites `issuer` + `device_authorization_endpoint` + `token_endpoint` to broker URLs, caches the rendered body with a 5-minute TTL. Lazy refresh on TTL expiry, stale-while-error on refresh failure. Constructor blocks on initial fetch so a misconfigured/unreachable IdP fails the broker at boot rather than at first `/soul-join`.
- `tools/demarkus-broker/internal/broker/discovery_test.go` (new) — 13 test cases via httptest fake-IdP: constructor validation (broker URL + issuer required), upstream-failure failure paths, override correctness, proxy of `jwks_uri` + `userinfo_endpoint` + `authorization_endpoint` + arrays, response headers, cache hit count within TTL, refresh after TTL, stale-while-error, recovery from transient failure, trailing-slash trim, malformed JSON rejection.
- `tools/demarkus-broker/internal/broker/server.go` — `Server` gains a `discovery *Discovery` field and `NewServer` takes it as a constructor arg. `Routes()` registers `GET /.well-known/openid-configuration` only when `discovery != nil`, so existing tests pass `nil` and skip the route cleanly.
- `tools/demarkus-broker/internal/broker/server_test.go` — `TestWellKnownDiscoveryRouteRegistered` (wires real Discovery into NewServer, asserts override applied through the mounted route) + `TestWellKnownDiscoveryRouteSkippedWhenNil` (404 when constructed nil).
- `tools/demarkus-broker/main.go` — `NewDiscovery` called between `NewVerifier` and `NewServer`; passes `cfg.Server.PublicURL` + `cfg.OIDC.Issuer`. Failure is fatal at startup, same shape as `NewVerifier`.
- `tools/demarkus-broker/internal/broker/config.go` — new `ServerConfig.PublicURL` field, required at load, trailing slash stripped once at load so every downstream consumer sees the canonical form. Doc comment notes it intentionally diverges from `OIDC.RedirectURL` (which is purpose-specific to the IdP redirect).
- `tools/demarkus-broker/internal/broker/config_test.go` — 2 new subtests: required-rejection + trailing-slash trim.
- `deploy/helm/demarkus-broker/values.yaml` — `server.publicURL: ""` with full operator-facing comment.
- `deploy/helm/demarkus-broker/templates/secret-config.yaml` — renders `publicURL: {{ required ... }}` so chart-render fails clearly when omitted (same shape as `oidc.redirectURL`).
- `deploy/helm/demarkus-broker/tests/secret-config_test.yaml` — 2 new cases (renders value, fail-render when blank) + added `server.publicURL` to the suite-wide `set:` block.
- `deploy/helm/demarkus-broker/tests/deployment_test.yaml` — same suite-wide `set:` addition (this suite also templates secret-config).
- `deploy/kind/values-broker.yaml`, `deploy/kind/values-broker-argo.yaml` — set `server.publicURL: "http://localhost:8080"` to mirror the existing redirectURL shape. Stage 2/4 harnesses don't exercise the well-known route but the broker's `LoadConfig` now requires the field.

### Verification

- `go test ./internal/broker/ -count=1` → all green (4.3s). 13 new Discovery tests + 2 new server route tests + 2 new config tests.
- `helm unittest .` → 55/55 pass across all 7 suites (was 52/52 before; 3 new).
- `bash pre-commit.sh` → format + vet + lint clean.

### Design notes (worth remembering)

- **Override shape is intentionally lossy at the seam.** Override `issuer` to broker URL but leave `jwks_uri` pointed at the IdP. ID tokens during PR2/PR3 are still IdP-signed and carry IdP's `iss`. Strict client validation against this discovery doc would fail; the plugin's device-flow client (PR6) only consumes `device_authorization_endpoint` + `token_endpoint` from this doc so the mismatch is invisible to it. PR4 closes the gap by minting broker-signed id_tokens with a broker-hosted `jwks_uri`. Doc comment in `discovery.go` calls this out explicitly so a future reader doesn't trip over it.
- **`map[string]any` proxy beats a typed struct.** Tried a typed `idpDiscovery` struct first; killed it because real IdPs ship 20+ fields each (Google's `code_challenge_methods_supported`, Auth0's `mfa_challenge_endpoint`, Okta's `request_object_signing_alg_values_supported`, etc.) and the broker has no business knowing or filtering them. Decode → mutate three keys → re-encode is the right shape; tests assert both the overridden fields AND a couple proxy fields so regressions surface.
- **Lazy refresh, not background goroutine.** Plan §Risks talks about "5-minute TTL on the discovery cache." Two implementation shapes: background ticker, or in-handler lazy. Picked lazy because (a) one fewer goroutine lifecycle to wire into the broker shutdown path, (b) the load is human-scale — even with N replicas behind a Service, the per-instance refresh rate caps at 1/5min, (c) thundering herd on simultaneous expiry is negligible at this rate (two replicas might both refresh once; the IdP doesn't notice). Stale-while-error keeps the well-known endpoint available during transient upstream blips.
- **Constructor signature pattern.** `NewDiscovery` takes a `DiscoveryConfig` struct, not a long positional arg list — per /guidelines.md "more than 4 parameters is a smell." Same pattern as the existing `Issuer`/`Verifier` constructors take typed configs.
- **Test isolation gotcha.** Existing `oidc_test.go` already had `fakeIdP` + `newFakeIdP`. Renamed mine to `fakeDiscoveryIdP` + `newFakeDiscoveryIdP` rather than touch the existing symbol — both are test-package-scope so the rename is purely local. Worth keeping in mind if a third test file ever needs a fake IdP: extract to a shared `testhelpers_test.go` helper instead of accumulating per-suite copies.
- **`http.NoBody`, not `nil`, on GET requests.** gocritic flagged the `nil` body on `http.NewRequestWithContext`; switched to `http.NoBody` (the idiomatic singleton for empty request bodies). Same fix in tests using `httptest.NewRequest`.

### Scope discipline

PR2 spec called for ~150 lines + tests. Final tally: ~210 lines of production code (discovery.go) + ~310 lines of tests + ~70 lines of config/chart plumbing + ~50 lines of dev-values updates. Over the 150-line estimate but every piece is load-bearing for PR3 (verification_uri uses brokerURL) and PR4 (broker-signed tokens use brokerURL as issuer).

### Next

PR3 — broker device flow (RFC 8628). New file `device.go` with `/device/authorize` + `/device` (HTML form + `/auth/login` redirect glue) + `/device/token` polling. ~600 lines + tests, ~2 days. Will exercise the route registration path that PR2 sets up; will also be the first time the broker holds short-lived per-flow state in-memory (device_code map with janitor goroutine).

### Open question to resolve before PR3

mock-oauth2-server device-code support — plan §Open Questions item 1. Need to check `navikt/mock-oauth2-server` v2.x source for `/device_authorization` endpoint before designing the kind Stage 5 harness in PR7. Not blocking PR3 itself (broker-side tests use a fake verifier), but if mock-oauth2-server doesn't support it, the kind end-to-end story diverges.


## End of session — PR2 merged, PR3 plan written

- PR2 (#136, broker discovery doc) merged after two rounds of CodeRabbit feedback. Final state included `Server.PublicURL` config field (required, trimmed, absolute-URL validated), `Discovery` type with 5-min TTL caching + refresh-mutex stampede protection + hard fetch deadline, route registration on `/.well-known/openid-configuration`, 16 broker tests + 5 helm-unittest cases.
- Coderabbit lessons worth saving:
  - `t.Fatalf` inside spawned goroutines panics that goroutine without releasing pending channel sends. Concurrency tests need an error-returning helper that surfaces failures through the channel; the main goroutine asserts after `<-`. Wrote `serveAndDecodeErr` as the canonical pattern for this kind of test.
  - When a constructor accepts an injected `*http.Client` via config struct, that client may not have a `Timeout` set. Wrap the fetch context with `context.WithTimeout` inside the operation so the deadline holds regardless of what the caller injected. Belt-and-suspenders on top of the default client's own timeout.
  - `helm install` regression tests in CI (`test-upgrade-wipe.sh` invocation) need explicit `--set` for every newly-required chart value. Adding a required field to `values.yaml` without updating CI passes helm-unittest but fails the actual install regression. Worth grepping `.github/workflows/` for `helm install` calls when adding a required field to any chart.
  - README install examples count as a test surface — coderabbit flagged the missing `--set server.publicURL` in the dev-install README block. Update README install commands alongside the chart change.
- PR3 plan published to `/plans/universe-onboarding-pr3.md` with full architecture, sub-task breakdown, open design questions, and tomorrow-morning resume steps. Index updated to surface it.
- Two design questions deferred to tomorrow's session:
  1. `Verifier.Exchange` signature change (lean: change it, three call sites, clean refactor) vs. parallel `ExchangeWithTokens` method. Latter is messier and we'd refactor anyway in PR4.
  2. RFC 8628 `slow_down` interval-increment policy. Lean: not for PR3 (RFC says MAY, not MUST); revisit if a customer reports IdP abuse.
- Tomorrow's first move: `mark_fetch /plans/universe-onboarding-pr3.md`, confirm the two open questions, branch from main, start at Step 1 (Verifier refactor) as its own commit.