Files
cairnobs/docs/architecture.md
T
jcoffey-dev 823f5d48d1 Unify the Tenant CRD with enterprise-api -provision-tenant (lightweight)
Closes a gap named across CLAUDE.md/docs/architecture.md/deploy/README.md
since early Phase 4: the operator's Tenant CRD and -provision-tenant
were two disconnected mechanisms. The operator's reconciler generated a
K8s Secret with a locally-generated random password that authenticated
against nothing (nothing ever called ClickHouse to create a matching
user), and unconditionally claimed status.phase=Active the moment a
Tenant object existed -- actively misleading, not just incomplete.

Two unification shapes were considered (surfaced to the user via
AskUserQuestion, given the real difference in blast radius): the
operator's reconcile loop becoming a second real actor (new Postgres +
ClickHouse admin credentials flowing into the K8s controller, plus real
reconcile-loop idempotency/retry design for an inherently one-shot
external side effect), or keeping -provision-tenant as the sole real
actor and having it also sync its result into the CRD. Went with the
lighter option.

enterprise/internal/tenantcrd (new): a Syncer using the K8s dynamic
client (unstructured.Unstructured + a GroupVersionResource, not
deploy/operator's typed Tenant struct -- avoids a cross-module Go
dependency between two independently-versioned modules for one type).
Upserts the Tenant object, creates/updates a Secret with the *real*
ClickHouse credentials owned by that Tenant via an OwnerReference, then
patches status.{clickHouseDatabaseName,clickHouseSecretRef,
tantivyIndexPath}. Idempotent and safe to retry: never rotates a
credential across a re-sync, never overwrites a pre-existing
spec.displayName a human/GitOps process set.

cmd/enterprise-api/main.go's runProvisionTenant calls Sync when
TENANT_CRD_NAMESPACE is set (empty = no-op, same shape as every other
optional dependency in this codebase). Its "already active" refusal is
now split: ClickHouse re-provisioning is still refused (rotating a live
credential would break every open connection for no benefit), but CR
sync alone is now retryable using the credentials already on file in
rbacstore -- needed for retrying a previously-failed sync, or
backfilling CR sync for a tenant provisioned before this existed.

deploy/operator's reconciler rewritten to match: it never claims
PhaseActive on its own initiative anymore, only once
status.ClickHouseDatabaseName is non-empty (the field -provision-tenant,
and only -provision-tenant, sets). Phase is now a pure function of
{spec.suspended, status.ClickHouseDatabaseName != ""} recomputed every
reconcile, not toggled in place -- fixes a related bug the old code
would have hit once suspension was involved: un-suspending an
already-provisioned tenant needs to return straight to Active, which
isn't derivable from "last observed phase was Suspended" alone. The
reconciler no longer creates or manages any Secret, dropped its
`secrets` RBAC grant entirely, and gained zero new dependencies.

Helm chart: enterprise-api gets its own ServiceAccount/Role/RoleBinding
(get/list/create tenants, get/update/patch tenants/status, get/create/
update secrets -- least-privilege, scoped to the release namespace, not
a ClusterRole) and a TENANT_CRD_NAMESPACE env var, both gated on
tenantOperator.enabled. tenant-operator's ClusterRole loses the
secrets grant it no longer needs.

Verified in this environment: enterprise/internal/tenantcrd's tests run
against k8s.io/client-go's fake dynamic + typed clientsets (real client
library, fake transport, no cluster needed); deploy/operator's rewritten
tenant_controller_test.go runs against controller-runtime's fake
client, including new regression tests for the "must not claim Active
without confirmation" and "un-suspending returns to Active, not
Provisioning" properties; helm template + parsing the rendered YAML
confirms the RBAC split renders exactly as designed under both
tenantOperator.enabled=true/false. Not verified: an actual
-provision-tenant run against a real cluster with the operator watching
(no live cluster in this environment, same disclosed limitation as the
rest of /deploy). Docs updated in lockstep: CLAUDE.md, docs/architecture.md,
deploy/README.md, deploy/helm/sentry/README.md (including a corrected
"Trying the two-tenant example" walkthrough), phase-4-runbook.md (new
§11), enterprise/README.md. Also fixed two unrelated stale claims found
along the way: docs/architecture.md still said docker-compose.yml ran
plain api unconditionally (fixed in an earlier commit, doc not updated
then), and enterprise-api's own main.go doc comment still said Helm/
docker-compose wiring wasn't built yet.
2026-08-14 09:07:10 -07:00

215 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. Writes always go to one shared (default) index (`ingest` isn't tenant-aware); reads can be scoped per-tenant via `SearchRequest.tenant_id` and `src/registry.rs`'s `IndexRegistry` (Phase 4) — 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`) and SAML login (`/auth/saml/login`+`/auth/saml/acs`, via `internal/saml`'s `crewjam/saml` wiring) — both a real IdP round trip, each verified with a real fake IdP (`coreos/go-oidc`'s `oidctest`, `crewjam/saml`'s `samlidp`) 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. Also `internal/searchclient` (per-tenant Tantivy routing, wired the same way into `search`). |
| `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 index-layer isolation is built, and verified.**
`search/src/registry.rs`'s `IndexRegistry` resolves
`SearchRequest.tenant_id` (added to `proto/sentry/search/v1/
search.proto`) to its own on-disk index, opened on demand;
`enterprise/internal/searchclient` sets that field from the
authenticated request identity, the same "read from ctx, fail closed"
shape `chrunner` uses. Unlike the ClickHouse pieces, this one actually
ran in the environment it was built in — Tantivy is an embedded
library, so the cross-tenant isolation probe needed no live database
or Docker to execute for real, and it passed.
- Neither storage engine's isolation extends to *ingest*: every record
`ingest` produces lands in the one shared ClickHouse database and the
one shared (default) Tantivy index regardless of tenant. A
newly-provisioned tenant's database/index are real and isolated at
query time — and permanently empty until something upstream of
`chrunner`/`searchclient` becomes tenant-aware on the write side,
which is undesigned, not merely unbuilt.
- `deploy/operator`'s `Tenant` CRD and `enterprise-api -provision-tenant`
are now unified, deliberately lightweight: `-provision-tenant` stays
the sole real actor (ClickHouse + `rbacstore`), and now also syncs its
real result into the `Tenant` CRD (`enterprise/internal/tenantcrd`) --
a real credential Secret, and status fields the reconciler
(`deploy/operator/internal/controller`) derives `Phase`/`Ready` from
rather than independently guessing. The reconciler itself gained no
new credentials and still never touches ClickHouse/Postgres.
**The deployment-topology gap is closed for both Helm and
docker-compose**: `deploy/helm/sentry/templates/api.yaml`/
`enterprise-api.yaml` are mutually exclusive on `enterprise.enabled`,
rendering to the same Service name and port either way, so a
Helm-deployed cluster can't accidentally run the wrong binary — the same
flag that turns on RBAC/audit/SSO now also chooses the query binary.
`docker-compose.yml`'s `api`/`enterprise-api` services are the same
mutually-exclusive choice via `COMPOSE_PROFILES` (`.env` defaults to
plain `api`), sharing a host-port/network-alias trick so `alerting`/
`web` need no conditional config either way. With both storage engines'
connection/index-layer mechanisms built, deployment topology enforced at
both the Helm and docker-compose layers, and the two provisioning
mechanisms unified, the largest remaining gap is ingest's lack of
tenant-awareness, which is undesigned, not merely unbuilt.
## 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.