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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.
71 lines
1.7 KiB
Go
71 lines
1.7 KiB
Go
// Package resolver provides iterative DNS resolution from root nameservers.
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// It traces the full delegation chain from IANA root servers through TLD
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// and domain nameservers, never relying on upstream recursive resolvers.
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package resolver
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import (
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"log/slog"
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"go.uber.org/fx"
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"sneak.berlin/go/dnswatcher/internal/logger"
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)
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// Query status constants matching the state model.
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const (
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StatusOK = "ok"
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StatusError = "error"
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StatusNXDomain = "nxdomain"
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StatusNoData = "nodata"
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StatusTimeout = "timeout"
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)
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// MaxCNAMEDepth is the maximum CNAME chain depth to follow.
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const MaxCNAMEDepth = 10
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// Params contains dependencies for Resolver.
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type Params struct {
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fx.In
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Logger *logger.Logger
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}
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// NameserverResponse holds one nameserver's response for a query.
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type NameserverResponse struct {
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Nameserver string
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Records map[string][]string
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Status string
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Error string
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}
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// Resolver performs iterative DNS resolution from root servers.
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type Resolver struct {
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log *slog.Logger
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client DNSClient
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tcp DNSClient
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}
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// New creates a new Resolver instance for use with uber/fx.
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func New(
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_ fx.Lifecycle,
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params Params,
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) (*Resolver, error) {
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return &Resolver{
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log: params.Logger.Get(),
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client: &udpClient{timeout: queryTimeoutDuration},
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tcp: &tcpClient{timeout: queryTimeoutDuration},
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}, nil
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}
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// NewFromLogger creates a Resolver directly from an slog.Logger,
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// useful for testing without the fx lifecycle.
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func NewFromLogger(log *slog.Logger) *Resolver {
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return &Resolver{
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log: log,
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client: &udpClient{timeout: queryTimeoutDuration},
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tcp: &tcpClient{timeout: queryTimeoutDuration},
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}
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}
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// Method implementations are in iterative.go.
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