The DNS-mock removal deleted TestQueryNameserverIP_Timeout and left a
comment in its place, so the resolver's StatusTimeout / StatusError
classification branch went untested. The stated obstacle was that a
query to a black-holed RFC 5737 address comes back StatusOK, because
the build environment transparently intercepts UDP/53 and answers it
locally. That is a property of that environment, not of the resolver,
and it only rules out choosing a remote address.
internal/resolver/transport_test.go binds real nameservers on
127.0.0.1 instead and aims the query at them: one silent on A queries
and answering every other type (StatusTimeout), one answering SERVFAIL
(StatusError), and one address with nothing listening, which is
refused rather than dropped and so classifies as NoData. This is not a
mock — no DNSClient is substituted. The resolver dials a real socket,
writes a real query with the real miekg/dns client, and applies its
real deadline and real classification logic to what comes back.
Substituting the client is what TESTING.md bans; choosing the server
is not, and the resolver is aimed at a caller-chosen nameserver in
production too.
queryDNS now dials a nameserver address that already carries a port as
written, defaulting to 53 only for a bare address. That is what makes
a nameserver on any other port reachable, on loopback or otherwise.
Silence on one record type rather than all eight keeps the timeout
test to two query timeouts (4s) instead of sixteen (32s), and it is
asserted: the test fails if it ever costs more than 8s.
The watcher's assertStatePopulated and TestDomainPortAndTLSChecks
asserted only that hostname, port and certificate state were
non-empty, plus non-zero checker call counts. Neither was vacuous, but
neither would have caught the watcher resolving the wrong addresses.
The port and TLS test doubles now record their arguments, and both
tests assert that the state keys and the arguments the checkers were
actually called with match the addresses live DNS returned — exactly
those, no more and no fewer. Verified by mutation: making the watcher
drop all but one resolved address fails both tests, and it passed both
of them before.
TESTING.md records why a loopback nameserver is not a mock, so the new
tests are not mistaken for a violation of the rule they respect.
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>
- 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.
clawbot
clawbotandclawbot