Rebasing this branch onto next surfaced two failures that the branch
did not have in isolation. Both come from the change this PR makes:
the watcher package now queries live DNS, and it is the second package
to do so.
Burst fan-out in the watcher package. All 13 watcher tests are
parallel and each runs a full iterative resolution, so they hit the
same root servers in the same instant and get rate-limited. This is
exactly the pathology internal/resolver/livedns_test.go was written to
prevent (9cb2c2b); that gate is package-scoped and cannot reach into
this package's test binary, so liveWatcherGate is its counterpart
here, acquired in newTestWatcher and released when the test ends.
Cross-package oversubscription. Go runs package binaries in parallel,
so with both live-DNS packages in flight their gates sum rather than
hold. The excess is rate-limited and the resolver's 8s per-attempt
deadlines expire, failing ResolveIPAddresses tests this branch never
touched. script/test now passes -p 1 so each gate is authoritative
while its package runs. Serialising is also net faster here, because
the retries it removes cost more than the lost parallelism: resolver
16-22s (was 30-36s under contention), watcher 12-13s (was 27-37s),
whole suite 39-46s against the 60s cap and the 90s -timeout backstop.
TestQueryNameserverIP_UnreachableServer is dropped rather than fixed.
It asserted that a query to an RFC 5737 documentation address comes
back non-OK with no records, which does not hold in the build
environment: that network transparently intercepts all UDP/53 traffic
regardless of destination and answers it locally, so the query returns
StatusOK with 9 real records for example.com. Verified directly with
dig @192.0.2.1 inside the build network. The mock DNSClient that used
to force this classification is what this PR removes, and a live
substitute would only be testing the sandbox's network behaviour, so
the coverage gap is recorded in a comment where the test was.
Verified: three consecutive `docker build .` runs green, after three
consecutive failures without these changes.
DNS is never mocked in this repository: tests exercise live DNS,
and robustness comes from handling real-world DNS behavior with
tolerant assertions and sensible timeouts, not from mocks.
watcher: drop mockResolver and wire the real iterative resolver
into the tests, querying stable public names (example.com,
www.example.com). Change detection is exercised by seeding the
state store with a synthetic previous observation that live DNS
cannot match (reserved .invalid nameserver names and RFC 5737
documentation addresses); DNS stays live in every run. The port
checker, TLS checker, and notifier remain test doubles since they
are not DNS, keeping notification and state assertions
deterministic against whatever addresses live DNS returns.
resolver: drop the timeoutClient fake DNSClient and the
NewFromLoggerWithClient mock constructor. The timeout test is
replaced by a live query against an RFC 5737 documentation
address where no nameserver can exist, asserting a classified
non-OK response with no records.
TESTING.md: extend the live-DNS policy to every package and
remove the carve-out that permitted DNS mocks in packages that
consume the resolver.
TODO.md: update stale references to hermetic mocked-DNS work to
reflect the no-mocking policy and the current state of
feature/resolver.
Intentionally dropped coverage: the exact StatusTimeout
classification (previously forced by the fake client) is no
longer asserted, because a genuinely unreachable server may fail
fast instead of timing out depending on the network path; the
live test tolerantly accepts any failure classification.
Rework of the unit at #93
(commit 9cb2c2b), against the review at
#136 (comment).
Review of 9cb2c2b found the quorum assertions could not fail on a
class of wrong answer. Each test banned exactly one bad status —
_AllReturnOK banned only nxdomain, _NXDomainFromAllNS banned only ok
— so resolver.StatusNoData passed both. nodata is a wrong answer, not
silence, and answeredCount counted it as answered, so it did not even
trigger a retry; with a quorum of 3 of 4 a single wrong nameserver
slid through undetected. That is assertion-loosening beyond what the
quorum change requires.
Tolerance is now a closed allowlist rather than a blocklist of one
status. unsanctionedStatuses() reports every per-nameserver result
whose status the caller did not explicitly sanction: ok/timeout/error
for the all-OK test, nxdomain/timeout/error for the NXDOMAIN test.
Silence (timeout, error) is the only thing quorum exists to tolerate;
any other status, including one added to the resolver later, fails by
name. answeredCount is likewise an allowlist of ok/nxdomain/nodata, so
an unknown status counts as silence and can only cause a retry and
then a loud failure, never a quiet pass.
Two harness tests cover the regression directly: three OK plus one
nodata (quorum satisfied, no nxdomain present — the input that used
to pass) is now reported as unsanctioned, and an unknown status is
neither counted as answered nor tolerated.
Verified by re-running the reviewer's probe: queryEachNS patched to
force one of google.com's four nameservers to return StatusNoData
turns both tests red, naming the offending nameserver and status —
--- FAIL: TestQueryAllNameservers_AllReturnOK (1.12s)
Should be empty, but was [ns1.google.com.=nodata]
every nameserver must answer OK or not answer at all:
ns1.google.com.=nodata ns2.google.com.=ok ns3.google.com.=ok
ns4.google.com.=ok
--- FAIL: TestQueryAllNameservers_NXDomainFromAllNS (1.34s)
Should be empty, but was [ns1.google.com.=nodata]
every nameserver must report NXDOMAIN or not answer at all:
ns1.google.com.=nodata ns2.google.com.=nxdomain
ns3.google.com.=nxdomain ns4.google.com.=nxdomain
— and green with the probe reverted. Also fixes the review's nit: the
per-attempt deadline assertion had no lower bound, so it passed for a
deadline far shorter than intended.
No production code changed; DNS is still never mocked.
The resolver's live-DNS tests failed nondeterministically, a different
subset each run. Three structural causes, all test-side:
- Burst fan-out. Every test in the package is parallel and the build
hosts have many cores, so all ~35 iterative resolutions started at
the same instant and, because queryServers walks rootServerList() in
fixed order, hit the same root server within milliseconds. Root
servers rate-limit that.
- No retry anywhere. One dropped UDP packet in a delegation chain
failed a test outright.
- Unanimity assertions. TestQueryAllNameservers_AllReturnOK and
_NXDomainFromAllNS required every one of a domain's nameservers to
answer, with no tolerance for one being slow.
New internal/resolver/livedns_test.go addresses each: a package-wide
gate bounds how many live resolutions are in flight at once, every
live operation gets three attempts with exponential backoff and its
own deadline, and multi-nameserver assertions now need a strict
majority rather than unanimity. The retry predicate is deliberately
transport-level -- "did a nameserver answer at all" -- never the
assertion under test, so a resolver that answers incorrectly still
fails on the first attempt. A nameserver that stays silent is
tolerated; one that answers wrongly is not.
livedns_harness_test.go tests that machinery directly: quorum
arithmetic, status counting, the gate's concurrency bound, per-attempt
deadlines, and recovery from a transient failure. It touches no DNS.
Nothing is mocked, faked, stubbed, recorded, skipped or build-tagged,
and production resolver behaviour is unchanged.
Test caps move to the new org-wide values ruled at prompts issue 41:
60s hard cap, 20s target, 90s -timeout backstop. REPO_POLICIES.md is
re-vendored byte-identical from sneak/prompts rather than hand-edited,
which also picks up the golangci-lint paragraph this copy had drifted
behind on. TESTING.md's stale 30-second target follows to 60.
#93
Root cause: `resolveARecord` and `resolveNSRecursive` sent recursive queries (RD=1) to root servers, which don't answer them. This caused 5s timeouts × 2 retries × 3 servers = hanging tests.
Fix:
- Changed `queryTimeoutDuration` from 5s to 700ms
- Rewrote `resolveARecord` to do proper iterative resolution through the delegation chain (query roots → follow NS delegations → get A record)
- Renamed `resolveNSRecursive` → `resolveNSIterative` with same iterative approach
- No mocking, no test skipping, no config changes
`make check` passes: all 29 resolver tests pass with real DNS in ~10s.
Co-authored-by: clawbot <clawbot@git.eeqj.de>
Reviewed-on: #28
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
The ErrNotImplemented sentinel error was dead code left over from
initial scaffolding. The resolver performs real iterative DNS
lookups from root servers, PortCheck does TCP connection checks,
and TLSCheck verifies TLS certificates and expiry. Removed the
unused error constant.
Per review feedback: tests now make real DNS queries against
public DNS (google.com, cloudflare.com) instead of using a
mock DNS client. The DNSClient interface and mock infrastructure
have been removed.
- All 30 resolver tests hit real authoritative nameservers
- Tests verify actual iterative resolution works correctly
- Removed resolver_integration_test.go (merged into main tests)
- Context timeout increased to 60s for iterative resolution
- Extract DNSClient interface from resolver to allow dependency injection
- Convert all resolver methods from package-level to receiver methods
using the injectable DNS client
- Rewrite resolver_test.go with a mock DNS client that simulates the
full delegation chain (root → TLD → authoritative) in-process
- Move 2 integration tests (real DNS) behind //go:build integration tag
- Add NewFromLoggerWithClient constructor for test injection
- Add LookupAllRecords implementation (was returning ErrNotImplemented)
All unit tests are hermetic (no network) and complete in <1s.
Total make check passes in ~5s.
Closes#12
Implement full iterative DNS resolution from root servers through TLD
and domain nameservers using github.com/miekg/dns.
- queryDNS: UDP with retry, TCP fallback on truncation, auto-fallback
to recursive mode for environments with DNS interception
- FindAuthoritativeNameservers: traces delegation chain from roots,
walks up label hierarchy for subdomain lookups
- QueryNameserver: queries all record types (A/AAAA/CNAME/MX/TXT/SRV/
CAA/NS) with proper status classification
- QueryAllNameservers: discovers auth NSes then queries each
- LookupNS: delegates to FindAuthoritativeNameservers
- ResolveIPAddresses: queries all NSes, follows CNAMEs (depth 10),
deduplicates and sorts results
31/35 tests pass. 4 NXDOMAIN tests fail due to wildcard DNS on
sneak.cloud (nxdomain-surely-does-not-exist.dns.sneak.cloud resolves
to datavi.be/162.55.148.94 via catch-all). NXDOMAIN detection is
correct (checks rcode==NXDOMAIN) but the zone doesn't return NXDOMAIN.
35 tests define the full resolver contract using live DNS queries
against *.dns.sneak.cloud (Cloudflare). Tests cover:
- FindAuthoritativeNameservers: iterative NS discovery, sorting,
determinism, trailing dot handling, TLD and subdomain cases
- QueryNameserver: A, AAAA, CNAME, MX, TXT, NXDOMAIN, per-NS
response model with status field, sorted record values
- QueryAllNameservers: independent per-NS queries, consistency
verification, NXDOMAIN from all NS
- LookupNS: NS record lookup matching FindAuthoritative
- ResolveIPAddresses: basic, multi-A, IPv6, dual-stack, CNAME
following, deduplication, sorting, NXDOMAIN returns empty
- Context cancellation for all methods
- Iterative resolution proof (resolves example.com from root)
Also adds DNSSEC validation to planned future features in README.
Implements the full monitoring loop:
- Immediate checks on startup, then periodic DNS+port and TLS cycles
- Domain NS change detection with notifications
- Per-nameserver hostname record tracking with change/failure/recovery
and inconsistency detection
- TCP port 80/443 monitoring with state change notifications
- TLS certificate monitoring with change, expiry, and failure detection
- State persistence after each cycle
- First run establishes baseline without notifications
- Graceful shutdown via context cancellation
Defines DNSResolver, PortChecker, TLSChecker, and Notifier interfaces
for dependency injection. Updates main.go fx wiring and resolver stub
signature to match per-NS record format.
Closes#2
Full project structure following upaas conventions: uber/fx DI, go-chi
routing, slog logging, Viper config. State persisted as JSON file with
per-nameserver record tracking for inconsistency detection. Stub
implementations for resolver, portcheck, tlscheck, and watcher.
clawbot
sneak
clawbotandclawbot