Files
cairnobs/docs/architecture.md
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jcoffey-dev 1fab02abd5 Phase 4: real OIDC human login (enterprise/internal/loginhandler)
Closes the other major named gap from this phase: until now, there was
no way for a human to actually log in -- only /alerting's RoleService
credential could be minted. GET /auth/oidc/login and GET
/auth/oidc/callback drive the real coreos/go-oidc flow already wired in
enterprise/internal/oidc: CSRF state in a short-lived cookie, code
exchange, ID token verification, upserting a users row, resolving
tenant/role from exactly one tenant_memberships row (refusing outright
on zero or more than one, rather than guessing), and issuing a real
session cookie.

Unlike everything else built this phase, this one is genuinely verified
end to end: the tests spin up coreos/go-oidc's own oidctest fake IdP,
which signs real RS256 ID tokens, and drive the full login->callback->
session-cookie round trip through actual signature verification -- no
live database or Docker needed, so nothing here is asserted without
having actually been run in this session. Also fixes a real bug caught
while wiring this into enterprise-auth's main.go: assigning a nil
*oidc.Provider to the handler's interface field would have produced a
non-nil interface wrapping a nil pointer (Go's classic typed-nil trap),
silently breaking the "OIDC not configured" no-op path -- New() now
takes the concrete pointer type and checks it before ever converting to
the interface, with a regression test pinning the fix down.

Still missing: SAML's equivalent (ACS endpoint), a tenant-picker UI for
multi-membership identities, and any admin UI to actually create a
tenant_memberships row (today that's manual SQL, documented in the
runbook's new bootstrap walkthrough).
2026-08-13 23:00:35 -07:00

189 lines
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Markdown

# Sentry Architecture
> **Status:** Updated through Phase 4. The component map/diagram below is
> still the Phase 0 request path (agent → ingest → ClickHouse → api →
> web) — it was never redrawn for the full-text search, dashboards/
> alerting, or enterprise/ additions; see each phase's runbook
> (`/docs/phase-N-runbook.md`) for what was actually verified when it
> shipped. The component responsibilities table and the sections below
> the diagram are kept current. Phase 0's original framing ("draft,
> correct as needed") still applies to anything not yet built.
## Mission
Open-core, Kubernetes-native centralized logging platform. Compete with
Splunk on features; win on cost-per-GB, a modern language stack, and
multi-tenant RBAC that's actually honest about its guarantees.
## Component map
```
┌──────────┐ gRPC/mTLS ┌──────────┐ produce ┌───────────┐ consume ┌────────────┐
│ agent │ ────────────▶ │ ingest │ ──────────▶ │ Redpanda │ ────────▶ │ ingest │
│ (Rust) │ │ (Go) │ │ (Kafka API)│ │ consumer │
└──────────┘ └──────────┘ └───────────┘ │ (Go) │
└──────┬─────┘
│ batch INSERT
┌────────────┐
│ ClickHouse │
└─────┬──────┘
│ SQL
┌───────────▼───────────┐
│ api (Go: gRPC+REST) │
└───────────┬───────────┘
│ REST
┌───────────▼───────────┐
│ web (SvelteKit) │
└────────────────────────┘
```
Decision (confirmed 2026-08-12): Redpanda stays in the Phase 0 path. The
`ingest` service's gRPC front end produces to Redpanda rather than writing
ClickHouse directly; a separate consumer path reads from Redpanda and batches
inserts into ClickHouse. This exercises the real transport layer from day
one instead of deferring it, and keeps Kafka credentials off the edge agent.
## Storage / query split
- **ClickHouse** is the analytical store of record for structured log data:
timestamp, host, service, severity, message, plus a `Map(String,String)`
for arbitrary structured fields. Partitioned by day, ordered by
`(service, timestamp)`.
- **Tantivy** (Phase 1) will provide full-text indexing over the `message`
field and unstructured payloads, queried out-of-band from ClickHouse and
joined by a log identifier. Not built in Phase 0.
- **Schema-on-write** using OTel semantic conventions as the default log
schema; schema-on-read fallback for unstructured/raw text that doesn't fit
the structured columns (captured via the `Map` column and/or a raw
passthrough field).
- **Postgres** (Phase 3) holds control-plane config only — dashboards,
panels, notification targets, alert rules/state, delivery log, and
(Phase 4) tenants/users/tenant_memberships/audit_log. Never log data;
ClickHouse/Tantivy stay the only place a log record itself lives. See
`/docs/phase-3-dashboard-design.md` for why ClickHouse's MergeTree
family isn't a fit for this (no real row-level locking/transactional
read-modify-write).
This split is not to be changed without discussion — see CLAUDE.md.
## Component responsibilities
| Component | Responsibility |
|---|---|
| `agent` (Rust, musl) | Tail a log file or read journald; parse RFC 5424 syslog with raw passthrough fallback; batch; ship via gRPC/mTLS to `ingest`. Windows (ETW/Event Log) code exists but is unverified on real Windows hardware — see `/agent/README.md`. |
| `proto` | Shared `.proto` contracts for agent↔ingest and api↔search gRPC, versioned independently of either side. |
| `transport` | Redpanda docker-compose + topic provisioning scripts. No application code. |
| `ingest` (Go) | gRPC server accepting agent connections; produces normalized OTel-log-like records to Redpanda; separate consumer reads from Redpanda and batch-writes to ClickHouse. No tenant concept — every record lands in the one shared `logs` table regardless of source (see "Tenant isolation" below). |
| `storage` | ClickHouse schema migrations + docker-compose for local/homelab. |
| `search` (Rust, Phase 1) | Consumes the same Redpanda topic `ingest` does (own offset tracking), builds a Tantivy full-text index over `message`, serves matches over gRPC. One shared index for every tenant today — see "Tenant isolation" below. |
| `api` (Go) | gRPC + REST gateway. `POST /query` compiles pipe-syntax or raw SQL to one IR, executed across ClickHouse/Tantivy (`/docs/query-language-design.md`). `internal/dashboards` is CRUD only — panel query execution happens client-side, reusing `/query`. `internal/authz` (Phase 4) enforces RBAC via a network call to `enterprise-auth`, never an import. |
| `alerting` (Go, Phase 3) | Evaluates alert rules on an interval, calls `api`'s `POST /query` (via a `RoleService` credential once Phase 4 auth is configured — see `/docs/phase-4-isolation-design.md`'s alerting↔api gap), delivers firing/resolved notifications (webhook/Slack/PagerDuty). |
| `enterprise` (Go, commercial license, Phase 4) | OIDC login (`internal/loginhandler`'s `/auth/oidc/login`+`/auth/oidc/callback`, real IdP round trip, verified with a fake IdP but not a real external one), RBAC storage (`internal/rbacstore`), session/service-token issuance (`internal/session`), the append-only audit log (`internal/audit`), `enterprise-auth`'s HTTP surface (`/internal/authorize`, `/auth/features`), per-tenant ClickHouse provisioning (`internal/tenantprovision`) and query routing (`internal/chrunner`), and `cmd/enterprise-api` — a second binary combining core's `api/queryapi`/`api/dashboards` handlers with these tenant-aware implementations. Never imported by core — see "Licensing boundary" below. Does **not** yet include per-tenant Tantivy routing or SAML's login ACS handler (protocol mechanics only) — see `/docs/security/threat-model.md`. |
| `web` (SvelteKit, static build) | Query bar, dashboards, alerts, and (Phase 4) a settings page that renders SSO status via a runtime capability check (`GET /auth/features`) rather than bundling enterprise-licensed components. |
| `cli` (`sentryctl`) | `ping`, `query`, `dashboards` (list/get/apply), `alerts` (list/get/apply). `$SENTRYCTL_TOKEN`, if set, is forwarded as a Bearer credential (Phase 4). |
| `deploy` | A Helm chart covering every `docker-compose.yml` service, plus (Phase 4) a small Go Operator managing one CRD (`Tenant`) that provisions a per-tenant ClickHouse credential Secret. Never applied to a live cluster in the environment this was built in — see `/deploy/README.md`'s verification section before trusting it. |
## Tenant isolation model (Phase 4)
Full design rationale: `/docs/phase-4-isolation-design.md`. Full honest
accounting of what's actually enforced vs. designed-only:
`/docs/security/threat-model.md` — read that before assuming any claim
below holds for log data specifically.
**As designed:** one dedicated ClickHouse database + narrowly-granted
user per tenant (never the shared `default`/admin credential), one
dedicated Tantivy index directory per tenant, `system.*` access revoked
per tenant, connections resolved from an immutable per-tenant map (never
a shared pool with session-level `USE`). Isolation lives at the
**connection layer** — every query, compiled or raw SQL, is forced
through a tenant-scoped connection the database's own access control
enforces — not at the query-compiler layer, since Phase 2's raw-SQL
escape hatch is opaque to any compiler-injected filter.
**As built, currently:**
- Role-based access control (`api/authz`) is live on `/query`
and `/dashboards`, resolved via `enterprise-auth` over HTTP.
- Control-plane tenant scoping is live for dashboards
(`api/dashboards`'s store filters every query by the
authenticated identity's tenant, never a client-supplied field).
- The `alerting``api` service-identity gap (task 2's finding) is
closed: a `RoleService` credential, distinct from every human role.
- **ClickHouse connection-layer isolation is built**, but lives in a
second binary: `enterprise/internal/tenantprovision` (real `CREATE
DATABASE`/`CREATE USER`/`GRANT` against ClickHouse) and
`enterprise/internal/chrunner` (a per-tenant connection registry
implementing `api/querylang/executor.SQLRunner`, resolving the
right tenant's connection from the authenticated identity in request
context) are wired into `enterprise/cmd/enterprise-api` — a binary
that imports both `api`'s handler packages and enterprise's
tenant-aware implementations (the allowed `enterprise → api` import
direction; core still never imports `enterprise/`). Real integration
tests assert a tenant cannot read another tenant's database by
fully-qualified name, and that `system.query_log`/`system.tables`/
`SHOW DATABASES` don't leak across tenants either — written but not
yet run against a live ClickHouse in this environment, see
`/docs/security/threat-model.md` and `/docs/phase-4-runbook.md`'s
verification-status sections. Plain `api/cmd/api` still exists,
unchanged, with its single shared connection — nothing forces a
deployment to run `enterprise-api` instead, and nothing flags it if it
doesn't.
- **Tantivy connection-layer isolation is not built.** `search`'s gRPC
service and `proto/sentry/search/v1/search.proto`'s `SearchRequest`
still carry no tenant field. Every tenant's free-text queries hit the
same shared Tantivy index regardless of which binary serves the
request.
- `deploy/operator`'s `Tenant` CRD still manages only the K8s-side
artifact (a credential Secret); the Helm chart has no service
definition for `enterprise-api` yet.
Building `enterprise/internal/searchclient` (the Tantivy-side sibling of
`chrunner`) and giving the deployment topology (Helm chart, or at least
clear documentation) an actual way to route traffic to `enterprise-api`
instead of `api` are the two largest remaining gaps between this system
and the isolation model it was designed to have.
## Licensing boundary
AGPLv3 for core + agents. Enterprise features (SSO, RBAC storage, audit
logging) live under `enterprise/` (commercial license stub, added
Phase 4). AGPL code must never import from `enterprise/` — enforced in
CI by `hack/check-tenant-boundary.sh`, which greps every build for the
import edge. Where core needs a decision only `enterprise/` can make
(is this request authorized, what SSO is configured), it calls
`enterprise-auth` over plain HTTP instead
(`api/authz.HTTPAuthorizer`, `web`'s `GET /auth/features`) —
the same "network boundary, not import boundary" shape `/alerting``api`
already used before `enterprise/` existed.
## Non-negotiables carried from CLAUDE.md
- Rust agent: statically linked musl, `x86_64-unknown-linux-musl` and
`aarch64-unknown-linux-musl`, no glibc runtime deps.
- Windows support via native ETW/Event Log API, not WSL — designed
(Phase 1) but still unverified on real Windows hardware.
- Every UI action maps to a documented REST/gRPC call — no UI-only logic.
- Pinned stack (see CLAUDE.md table) — no substitutions without discussion.
## Explicitly out of scope (current, Phase 4)
Per `/CLAUDE.md`'s Phase 4 non-goals and `/docs/security/threat-model.md`:
deny-override permission grants, a data retention/deletion policy for
deprovisioned tenants, general multi-cluster orchestration in `/deploy`,
and any defense against a privileged ClickHouse/Postgres administrator —
every isolation and audit-integrity guarantee here is a structural
defense against application-layer bugs, not an operational control.
## Open questions for you to resolve
- Retention/TTL policy for the ClickHouse `logs` table — not specified yet,
deferred until storage sizing is a real concern.
- Exact OTel log schema field mapping (which OTel resource/log attributes
map to which ClickHouse columns) — Phase 0 uses a minimal subset
(timestamp, host, service, severity, message, attributes map); full
mapping deferred.
- mTLS certificate provisioning/rotation story for agents — Phase 0 will use
a static dev CA and manually issued certs; production PKI design is
out of scope here.