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Start Here: RedFlag Architecture Overview
Version: v0.2.8.0 (June 2026)
This is the entry point into the RedFlag Architecture Framework. Read this first to understand the shape of the system, then follow the links into the detailed docs.
What RedFlag Is
A self-hosted update management platform for homelabs and small MSPs. Centralized visibility and control over software updates across Linux, Windows, and Docker — with a cryptographic supply chain gate that most commercial RMM tools don't attempt.
The Two Capability Tiers
Tier 1: Update Management
Agents register with a one-time token and a hardware fingerprint (TOFU). The server issues Ed25519-signed commands; agents verify signatures, check nonces, reject replays. Pull-based polling (5 min default, rapid mode available). Subsystem scanning across apt, dnf, winget, WUA, and Docker.
Packages move through a server-owned state machine (pending through installed or
failed) with typed transitions and guarded UPDATEs — no free-form string jumps. A
lifecycle orchestrator drives auto-advance and recovers stuck states.
Architecture docs:
- core/01-ethos — the five principles
- core/02-architecture-decisions — the twelve foundational choices
- security/02-authentication-stack — four-layer auth (reg tokens, JWT, refresh, machine binding)
- security/01-trust-boundaries — endpoint classification and middleware matrix
- flows/06-update-lifecycle — state machine, two execution paths, orchestrator
Tier 2: Supply Chain Gate
The differentiator. The server is the signing authority — it evaluates policy (OSV
vulnerability checks, package age, human approval) and mints an Ed25519-signed
capability token describing exactly one operation over a fully-resolved dependency
closure. A privileged, network-less Rust executor (helper/) verifies the signature
and every artifact hash before performing that one operation.
The approval gate is fail-closed: a known vulnerability anywhere in the resolved closure — top-level or transitive — blocks the token from being minted. The operator must override with a documented reason. The override waives the vulnerability judgment only; signing and hash verification have no skip path.
Auto-confirm shares the same ClosureCleared predicate as manual approval — the two
paths cannot drift on what counts as a clean closure.
Architecture docs:
- security/05-supply-chain-gate — the design of record: capability model, wire contract, load-bearing constraints, enforcement layers, trust chain, hash registry
docs/tasks/GATE-000-supply-chain-gate-plan.md— build status & implementation tracking (not design)
Process Explorer
On-demand /proc filesystem scanning for process inventory and drill-down detail.
Triggered when a user opens the Processes tab — no background broadcasting.
25+ fields per process (osquery parity) plus 7 related data types (open files,
sockets, pipes, environment keys, memory map, namespaces, listening ports).
Data collection caps are server-controlled via ProcessExplorerConfig (Settings →
Process Explorer) and delivered to agents on check-in. Listening ports use socket
inode correlation against /proc/net/tcp — not system-wide assignment.
Architecture docs:
- scanners/05-process-scanner — data model, collection, caps
- flows/07-process-scan — command-dispatch flow, API endpoints, schema
Architectural Boundaries
Agent is a Stateless Executor
The agent receives commands, executes them, and reports results. It does not track lifecycle states. The server owns every state transition. The agent's only autonomous decisions are: verify this signature, check this nonce, reject this replay.
Mutation Only Through the Helper
On capability-gated ecosystems (dnf, apt), the agent cannot run install commands
directly. All mutation flows through consumer.go → sudo systemd-run --pipe →
redflag-helper. The agent holds zero sudo for installs. Discovery (scan, dry-run,
hash-resolve) runs unprivileged through DiscoveryRunner.
Two Execution Paths
- Capability gate (dnf, apt): token minted at approval → agent polls for tokens → helper verifies + executes → agent reports receipt. No install command issued.
- Legacy command (docker, winget, windows_update): signed command → agent executes directly via type-asserted installer methods → reports via ReportLog.
The legacy path is a known gap — the gate design covers these ecosystems but implementation is deferred.
Six Load-Bearing Constraints
From security/05-supply-chain-gate.md — do not regress these:
- Sign the resolved closure, not the top-level package
- The signer lives off the web process (seam documented, not yet isolated)
- Verified-cache fallback, fail-closed only on change
- Verify keys, not servers
- Kernel stops are defense-in-depth, not a prerequisite
- No doctrinal knobs — signing required and forward-only are not configurable
Navigation
| Section | What It Describes |
|---|---|
| core | ETHOS principles, architectural decisions |
| components | Server, agent, web, helper — package structure and responsibilities |
| security | Trust boundaries, auth stack, machine binding, supply chain gate |
| verification | Ed25519 signing pipeline, agent verification, key rotation, replay protection |
| scanners | Per-ecosystem scanner behavior and integration points (incl. process scanner) |
| flows | Data flows — registration, command execution, upgrade, heartbeat, capability advertisement, update lifecycle |
| reference | File mappings, glossary |
Honest Gaps
- Gate policy visibility: the soak and age gates are live policies as of v0.2.6.2 (
supply_chain.*settings — see security/05-supply-chain-gate §4), but the dashboard doesn't yet surface their configuration; operators tune them blind. The live install-through-helper path completed e2e on 2026-06-05 - Closure transitivity split by platform: dnf/apt resolve via dry-run (full closure); npm/pypi still single-entry
- Signer in-process: key encapsulated in SigningService, minter is the only caller — but true process isolation not built
- Legacy ecosystems ungated: docker, winget, windows_update still direct-mutation
- Kernel enforcement inert: eBPF scaffold exists, not wired to the capability model
These are architectural gaps, not bugs. They define where the system's protection
boundary currently ends. Task tracking for closing them lives in docs/tasks/.
Last reviewed: 2026-06-10