gonemaster architecture

Last reviewed: 2026-05-17.

1. System overview

gonemaster tests DNS zones for delegation, configuration, and protocol problems. A test run executes a fixed suite of testcases against a zone and emits a structured stream of findings; each finding carries a severity, a tag, and machine-readable arguments. Findings aggregate into a numeric score and letter grade. The engine is exposed through four surfaces: a local CLI (gonemaster), a Nagios-compatible probe (gonemaster-nagios), an HTTP service with embedded web UIs (gonemaster-server), and a CLI client for that service (gonemaster-client).

   [gonemaster]   [gonemaster-nagios]   [gonemaster-client]
        |                  |                     |
        |                  |                     | HTTP
        |                  |                     v
        |                  |          [gonemaster-server] <--> [Database]
        |                  |                     |
        +------------------+---------------------+
                           |
                           v
                       [engine] --> [DNS]

Each binary instantiates its own engine. The engine itself has no shared state across binaries.

2. Component map

gonemaster ships four binaries and three web UIs. The UIs are built to static assets and embedded into gonemaster-server with go:embed.

Binaries

gonemaster, gonemaster-nagios, and gonemaster-server are self-contained: each can run without the others. gonemaster-client requires gonemaster-server.

Embedded UIs

gonemaster-server serves three independent Svelte 5 + Vite frontends.

Build tags:

• nogui drops all three UIs. API routes are unaffected; UI routes return 404 ui not available.
• badkeys_embed embeds the badkeys blocklist into the binary.

HTTP surfaces

/ and /api/v1/ have no built-in authentication. Deployments restrict them to a trusted network or place them behind a reverse-proxy auth layer. /public/, /analysis/, and /pub/api/v1/ are designed for direct internet exposure behind a rate-limiting reverse proxy.

Further reading: docs/cli/ , docs/server/ , docs/client/ , docs/nagios.md , docs/analysis/ .

3. Request lifecycles

Three concrete flows through gonemaster-server, each shown as the ordered steps between HTTP entry and terminal state.

3.1. Single-domain test (public API)

Entry: POST /pub/api/v1/jobs → handlePublicCreateJob (server/handlers_public.go ).

1. Validate and normalize the domain.
2. Create an in-memory Job with status=JobQueued.
3. Persist the job via Store.Create.
4. Enqueue at PriorityNormal via Queue.Enqueue.
5. A worker dequeues, acquires the engine concurrency limiter, and transitions the job to JobRunning (server/worker.go ).
6. Worker calls engine.Run, then Store.GraduateJob, which writes a Run row and its Entries and deletes the Job row.

State: JobQueued → JobRunning → JobSucceeded (or JobFailed, JobCanceled).

Result fetch: GET /pub/api/v1/jobs/{publicID}/result reads either the still-queued Job or the graduated Run and its Entries.

3.2. Batch submission (admin API)

Entry: POST /api/v1/jobs/batch → handleJobsBatch (server/handlers.go ).

1. Resolve the domain list directly or via a from_tag lookup.
2. Create one Job per domain, sharing a BatchID and Priority=PriorityBatch.
3. Persist all jobs; enqueue each at PriorityBatch.
4. Persist a Batch row recording DomainCount and metadata.
5. Workers consume the batch tier only after the normal tier is empty (server/queue.go ).
6. Each batch job follows the same runJob → engine.Run → GraduateJob path as a single-domain test.

State per job: JobQueued → JobRunning → JobSucceeded. A batch completes when every job graduates.

Poll: GET /api/v1/batches/{id} aggregates the in-flight Jobs and the graduated Runs for the batch to produce counts and the grade distribution.

3.3. Cohort snapshot read (public API)

Entry: GET /pub/api/v1/analysis/cohorts/{tag}/snapshots/{slug}/overview → handlePublicAnalysisOverview (server/handlers_public_analysis.go ).

1. Resolve the public cohort by source tag.
2. Resolve the snapshot by slug, or fall back to the cohort’s default snapshot.
3. Reject the request unless the snapshot has Status=Captured and IsPublic=true.
4. Read the pre-aggregated row from analysis_snapshot_overviews via Store.GetSnapshotOverview.
5. Return the aggregated payload with cache headers: immutable max-age=1y for an explicitly named captured snapshot, no-cache, must-revalidate for default-snapshot resolution.

Snapshot population is upstream of this read: batch jobs graduate into Runs, the worker projects each run into fact tables via analysis.ProjectRun, and a periodic loop materializes overview rows via analysis.CaptureCompletedSnapshots.

Further reading: docs/server/ , docs/analysis/ .

4. Data model

gonemaster-server stores two layers of persistent entities. Both are defined in server/models.go and persisted across backends through the Store interface.

Core entities

Domain and Tag records are shared metadata, not owned by any one batch. Deleting a batch does not remove the domains it tested.

Analysis layer

A second layer sits above Run for cohort analysis.

Projection and snapshot capture are read-optimized materializations: per-run projection lets cohort listings avoid scanning entries; snapshot capture lets public reads avoid scanning facts.

Lifecycle

   POST --> Job --graduate--> Run + Entries
                                   |
                                   v  per (run, cohort)
                       analysis_run_* projections
                                   |
                                   v  on snapshot-intent batch complete
                  Snapshot + analysis_snapshot_* views

Further reading: docs/server/database.md , docs/analysis/ .

5. Persistence backends

gonemaster-server supports four storage backends, selected at startup with --db-driver or GONEMASTER_DB_DRIVER.

The three SQL drivers share schema migrations; a dialect layer (server/store_sql_dialect.go ) translates one statement template into per-driver SQL.

Startup recovery

On a persistent backend, the server performs three steps before accepting requests:

1. Run pending schema migrations.
2. Mark any Job left in running state at the last shutdown as failed.
3. Re-enqueue any Job still in queued state.

memory skips this; the queue starts empty.

Retention

--db-retention-days N (or database.retention_days) runs an hourly purge of terminal Job and Run rows older than N days. 0 keeps results forever. Queued, running, and paused jobs are never purged automatically. Manual batch deletion is a separate operation and ignores the retention window.

Further reading: docs/server/database.md , docs/server/database-setup.md .

6. Concurrency model

gonemaster-server runs tests on a fixed worker pool fed from a two-tier priority queue. The engine itself is parallel-safe and is the same code used by gonemaster and gonemaster-nagios.

Engine isolation

engine.Run is re-entrant. Each call constructs isolated per-run state from its arguments; nothing is shared between concurrent runs through global variables. A binary may call engine.Run from many goroutines without external synchronization.

Worker pool

gonemaster-server starts WorkerCount worker goroutines on startup (default 16, server/config.go ). Each worker loops:

1. Dequeue the next job.
2. Mark the job running; register a per-job cancel function.
3. Acquire the engine limiter if one is configured.
4. Call engine.Run.
5. Graduate the job to a Run plus its Entries.

Workers can be resized without restarting the server. Scaling down cancels the last N worker contexts and they exit after their current job (server/worker.go ).

Priority queue

The queue has two tiers (server/queue.go ):

• PriorityNormal - interactive single-domain submits.
• PriorityBatch - batch and tag-sweep submits.

Workers always drain PriorityNormal before PriorityBatch. FIFO within each tier. Interactive requests are not starved by an active batch.

Engine concurrency limit

MaxConcurrentJobs caps the number of concurrent engine.Run calls when set above zero (default 0: no extra cap; only the worker pool bounds concurrency). Useful when the engine is bottlenecked on something other than worker goroutines, e.g. resolver capacity or DNS rate budgets.

Cancellation

The server keeps a map of jobID → context.CancelFunc (server/cancel.go ). Canceling a job calls the function, which cancels the per-run context. engine.Run returns promptly; the worker records the terminal state as canceled.

Further reading: docs/server/configuration.md , docs/server/performance.md .

7. Build and distribution

Build is driven by the Makefile . CI runs on Woodpecker .

Build targets

Build tags

• nogui drops all three embedded UIs. API routes are unchanged; UI routes return 404 ui not available. Used when Node is not available in the build environment.
• badkeys_embed embeds the gzipped badkeys blocklist into the binary. Without the tag, the blocklist is read from share/badkeys/ at runtime.

The tags compose: -tags "nogui badkeys_embed" is a valid build.

CI pipelines

.woodpecker.yml defines two pipelines.

Default pipeline (every push and pull request):

1. ui_checks - lint, test, and build the admin UI.
2. spec_check - validate testcase specs; check tag catalog, log args, and i18n placeholder drift.
3. go_test - go test ./... with GOMAXPROCS=4.
4. integration_test - server tests against PostgreSQL 17 and MariaDB 11 services started in-pipeline.
5. build_server_with_ui - confirm gonemaster-server builds with UI embedding.
6. deploy_pages (main branch only) - build the Hugo docs site and force-push to codeberg.org/pawal/gonemaster:pages.

A second pipeline for release artifacts is declared in .woodpecker.yml but has not yet been exercised; see Chapter 15 .

Further reading: Makefile , .woodpecker.yml .

8. Configuration and deployment

Configuration sources

Config is applied with this precedence (later wins):

1. Built-in defaults.
2. JSON config file (--config PATH).
3. GONEMASTER_* environment variables.
4. Command-line flags.

gonemaster-server --dump-config prints the effective config and exits.

Key settings

The full settings catalog lives at docs/server/configuration.md . The architecturally load-bearing sections:

Database DSNs belong in environment variables (GONEMASTER_DB_DSN); everything else fits in the JSON config file.

Deployment topologies

gonemaster-server is a single binary. It does not terminate TLS, does not authenticate admin paths, and binds to one listener.

   Single host (dev):
     user -> gonemaster-server -> SQLite

   Trusted network:
     browser --HTTPS--> proxy --HTTP--> gonemaster-server -> Postgres/MariaDB

   Internet-facing:
     internet --HTTPS--> proxy --HTTP--> gonemaster-server -> DB
     (proxy adds TLS, rate-limit, ACL; forwards only /public/, /analysis/, /pub/api/v1/)

Reverse-proxy expectations:

• TLS terminates upstream; gonemaster-server speaks plain HTTP.
• The proxy sets X-Forwarded-For; trusted_proxy_cidrs lists the proxy IPs whose X-Forwarded-For is honored.
• For internet-facing deployments, restrict / and /api/v1/ at the proxy.
• Rate limiting can run at the proxy or at the server (public_api.rate_limit_*); they compose.

Profiles

Profile resolution has two layers:

• A process-wide base profile, built from the engine default plus profile_path.
• Stored profiles in the database. Jobs, batches, public profile dropdowns, and tag defaults reference one by ID.

Stored profiles are sparse: they record only the overrides above the base profile. Each carries the engine schema version it was last edited against; the admin UI flags profiles that need review after an engine update.

Further reading: docs/server/configuration.md , docs/server/public-api-and-proxy.md , docs/server/operations.md .

9. Security posture

Authentication

/ and /api/v1/ have no built-in authentication. gonemaster-server expects either a reverse proxy to enforce authentication on those routes or the listener to be bound to a private interface. Public routes (/public/, /analysis/, /pub/api/v1/) are designed to require no authentication.

Content Security Policy

Three CSP policies are applied per route in server/server.go :

server/middleware_test.go asserts that the admin and public CSP must not regress to include 'unsafe-inline'. Inline style attributes and Svelte style: directives in those UIs are CSP violations and rejected in review.

Public API restrictions

The public API (docs/server/public-api-and-proxy.md ) is shaped for safe internet exposure:

• Job lookups use opaque public IDs only; internal job and run IDs never leave the public surface.
• POST /pub/api/v1/jobs accepts profile_id only when the stored profile is marked public.
• profile_overrides are rejected: public users cannot inject arbitrary resolver settings.
• public_api.allow_private_undelegated_ip defaults to false, blocking loopback, link-local, private, CGNAT, multicast, and broadcast IPs as undelegated NS targets.

Rate limiting

Public API rate limiting is off by default and is required for internet exposure. Configure with public_api.rate_limit_enabled, rate_limit_max, and rate_limit_window. The limit applies to POST /pub/api/v1/jobs, keyed by client IP after X-Forwarded-For resolution.

Trusted proxies

trusted_proxy_cidrs lists the CIDRs of reverse proxies allowed to set X-Forwarded-For. The default is empty: with no trusted proxies, the server uses RemoteAddr and ignores X-Forwarded-For. Set this to the proxy’s IP or CIDR before relying on rate limiting or per-client logs in a public deployment.

Secrets

Database DSNs and CI release tokens are passed via environment variables, never via the JSON config file:

• GONEMASTER_DB_DSN carries the database connection string.
• CODEBERG_PAGES_TOKEN and CODEBERG_RELEASE_TOKEN are injected into CI publish steps (.woodpecker.yml ).

There are no API keys to manage; access control to admin routes is host-level.

Supply chain

The badkeys blocklist (compromised public-key fingerprints) is updated by an explicit operator step, not as part of normal builds:

make badkeys-update         # fetch into share/badkeys/
make badkeys-update-embed   # additionally gzip for embedded builds

Builds without the badkeys_embed tag read the blocklist from share/badkeys/ at runtime. The CI pipeline does not refresh the blocklist on its own.

Further reading: docs/server/public-api-and-proxy.md .

10. Observability

gonemaster-server exposes three observability surfaces: a health probe, a metrics endpoint with JSON and Prometheus formats, and standard-output logs.

Health probe

GET /api/v1/healthz -> 200 {"status": "ok"}

Returns 200 unconditionally when the server is up. There is no separate readiness probe; the same endpoint serves both checks.

Metrics

GET /api/v1/metrics                # JSON snapshot
GET /api/v1/metrics?format=prom    # Prometheus exposition

The JSON snapshot has seven sections: health, jobs, api, quality, insights, trends, and metadata (schema_version, generated_at). Common fields:

• health.queue_depth, health.in_flight_jobs.
• jobs.completed_total.
• quality.outcomes.{success_rate, failed_rate, failed_total}.
• quality.severity.totals per severity level.
• trends.windows.{1h, 6h, 24h, 48h}.points[].

The Prometheus form exposes low-cardinality counters and gauges under the gonemaster_ prefix: server gauges (build, worker counts, queue depth, in-flight), DNS counters, job lifecycle counters and status gauges, API request counters and latency histograms, job-duration histograms, and locale usage. High-cardinality data (insight tables, trend point series) and precomputed ratios are JSON-only; Prometheus consumers derive ratios from counters and histograms.

Both formats share a 1-second response cache keyed by query parameters.

Logs

gonemaster-server writes plain-text logs to stdout via Go’s standard log package. Coverage includes server lifecycle, worker and queue events, API errors, and panic recovery (with stack). Logs are not JSON-structured.

Further reading: docs/server/metrics.md .

11. Testing strategy

Tests run at three levels: Go unit and integration tests, frontend tests, and spec-coherency checks. CI (.woodpecker.yml ) runs all of them on every commit.

Layers

make test is the canonical “did I break something” target. It runs ui-test, ui-public-test, test-go, spec-check, and ui-csp-check in that order.

Spec coherency

make spec-check runs four substeps; any drift is a CI failure, not a warning:

1. spec-validate - canonical testcase specs match implementation metadata (name, module, severity floors).
2. spec-check-tags - per-module tag catalog markdown files match the current tag registry.
3. spec-check-coherency - the log-args inventory regenerated from appendLog* call sites equals the committed one.
4. spec-check-i18n-placeholders - i18n template placeholders are on the allowlist; no legacy placeholders sneak in.

Each substep is runnable in isolation for fix-and-recheck loops.

Cross-driver integration

make test-integration starts PostgreSQL 17 and MariaDB 11 in Docker Compose, points the test suite at them via TEST_POSTGRES_DSN and TEST_MARIADB_DSN, and runs the server/... test packages against all three drivers (SQLite is in-process and always runs). The CI pipeline mirrors this with services declared in .woodpecker.yml .

Further reading: docs/dev.md , docs/specifications/log-args-coherency.md .

12. Specification and i18n discipline

Testcase metadata is partially generated and CI-enforced to stay coherent with the code. This chapter summarises what is generated, where it lives, and how drift is caught.

What lives where

Generation tools

Under tools/specifications/ and tools/i18n/ :

• export-implemented rebuilds the implemented-testcases inventory.
• generate-tag-catalog rebuilds the per-module tag catalog markdown.
• export-log-args rebuilds the log-args inventory from the engine’s appendLog* call sites.
• validate cross-checks canonical specs against implementation metadata.
• i18n/check-placeholders validates that template placeholders match the allowlist.

make spec-export runs the refresh path; make spec-check runs the verification path used by CI.

Enforcement

CI runs make spec-check on every commit (.woodpecker.yml ). The four substeps already listed in Chapter 11 apply: spec validation, tag catalog drift, log-args inventory coherency, i18n placeholder allowlist. Drift in any of them is a build failure.

After any change to appendLog*, message tags, or testcase metadata, the change author runs make spec-check locally before pushing.

i18n discipline

Log messages are localised through share/lang/*.po gettext-style catalogs (da, es, fi, fr, ja, nb, sl, sv). Templates use a fixed set of placeholders. New placeholders are rejected unless added to the allowlist consumed by tools/i18n/check-placeholders. This prevents one-off translator syntax from leaking into the runtime contract.

Further reading: docs/specifications/ , docs/specifications/log-args-coherency.md .

13. IP and licensing boundary

Project license

gonemaster is released under the BSD-2-Clause license (LICENSE ). Copyright is held by Patrik Wallström, the Swedish Internet Foundation, and AFNIC. The license file records contributor copyright on incorporated upstream code.

This chapter is the public licensing boundary only. Commercial extensions, hosted-service architecture, and customer-specific integrations do not appear in this document.

Direct Go dependencies

All direct dependencies are permissive OSS (BSD / MIT / MPL-2.0 family). Indirect dependencies are pinned in go.sum . An authoritative third-party-license inventory is open work (see Chapter 15 ).

Frontend dependencies

The three embedded UIs are Svelte 5 + Vite projects. JavaScript dependencies are pinned per UI in ui/package-lock.json , ui-public/package-lock.json , and analysis-ui/package-lock.json . Major direct dependencies are Svelte (MIT), Vite (MIT), and SvelteKit (MIT, analysis UI only).

Data assets

Further reading: LICENSE , go.mod .

14. External dependencies and vendors

gonemaster depends on external infrastructure only for builds, distribution, and runtime DNS testing. Hosting choices for any hosted offering are not part of this document.

Runtime DNS targets

The engine performs delegation tests by querying the public DNS hierarchy directly:

• Root zone servers, enumerated in share/named.root . The file ships with the binary; operators refresh it manually when IANA publishes updates.
• TLD and authoritative servers for the zone under test.
• The operator’s local resolver, only when explicitly configured as a fallback.

No DNS data is sent to a vendor-controlled resolver as part of normal operation.

Build and CI vendors

The release-artifact distribution channel is open work and not yet described here; see Chapter 15 .

Operator-driven external fetches

Further reading: .woodpecker.yml , go.mod .

15. Known limitations

This chapter records what is open, mitigated but not yet fixed, or shaped by pragmatic compromise.

Open engineering work

Testcase coverage

These files are the source of truth for missing or divergent testcase behaviour.

Operational risk areas

• Public API rate limiting is off by default (Chapter 9 ). Internet-facing deployments that forget to enable it can be saturated by a single client.
• trusted_proxy_cidrs defaults to empty. Without it, per-client rate limiting and access logs key on the reverse proxy’s address, not the originating client.
• No built-in backup tooling. Database backup is the operator’s responsibility; the server does not snapshot itself.
• memory backend loses in-flight jobs on restart. Use a persistent backend (SQLite, PostgreSQL, MariaDB) outside of development.

Not yet documented

Topics that warrant their own chapters as the system grows:

• Threat model. Tracked separately; docs/security/threat-model.md will land alongside the next security review.
• Performance benchmarks. Some operational guidance lives in docs/server/performance.md ; SLO-style numbers do not exist yet.

16. Glossary

Batch. A group of jobs submitted together, often for the domains in a tag.

Cohort. A curated public dataset backed by one source tag.

Entry. A single log line emitted during a run; carries a severity, a tag, and machine-readable arguments.

Grade. A letter (A+ through F) derived from the score.

Job. A queued test request in gonemaster-server. Graduates into a run when complete.

Profile. A configuration document that controls engine behavior: which modules and testcases run, resolver settings, severity overrides.

Run. An immutable record of a completed test, with its entries and metadata.

Score. A numeric value from 0 to 100 derived from a run’s entries.

Severity. One of DEBUG3, DEBUG2, DEBUG, INFO, NOTICE, WARNING, ERROR, CRITICAL.

Snapshot. An immutable view of a cohort, captured from one snapshot-intent batch.

Tag. Two unrelated namespaces. (1) In engine/ and run output: the identifier of a kind of entry, e.g. NS_SAME_IP. (2) In the admin UI and analysis: a user-defined named collection of domains.

Testcase. A single named test executed during a run, e.g. dnssec01. Testcases are grouped into modules.

Further reading: docs/scoring.md , docs/analysis/ , docs/specifications/ .

17. Appendix: Directory map

Top-level directories tracked in the repository.

Build outputs (bin/, embedded dist/ directories) are gitignored and not part of the source tree.