Pierre-Olivier Mercier
7e50f404a1
Generic SRV records checker for happyDomain.
For each SRV record attached to an svcs.UnknownSRV service, the checker
resolves every target and probes reachability:
- DNS resolution (A/AAAA), CNAME detection (RFC 2782 violation),
null-target detection (RFC 2782 "service explicitly unavailable")
- TCP connect to target:port for _tcp SRVs
- UDP probe for _udp SRVs, using ICMP port-unreachable detection
The checker also publishes TLS endpoints (host, port, SNI) for every
SRV target hitting a well-known direct-TLS port (443, 465, 636, 853,
993, 995, 5061, 5223, …) via the EndpointDiscoverer SDK interface, so
a downstream TLS checker can pick them up.
The HTML report groups records as cards and surfaces the most common
failure scenarios (DNS failure, CNAME target, TCP unreachable,
null-target) at the top with remediation guidance.
44 lines
1.3 KiB
Go
44 lines
1.3 KiB
Go
package checker
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import (
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"context"
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"fmt"
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"strings"
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sdk "git.happydns.org/checker-sdk-go/checker"
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)
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type ruleTargetsResolve struct{}
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func RuleTargetsResolve() sdk.CheckRule { return &ruleTargetsResolve{} }
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func (ruleTargetsResolve) Name() string { return "srv_targets_resolve" }
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func (ruleTargetsResolve) Description() string {
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return "Every SRV target resolves to at least one A/AAAA address."
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}
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func (ruleTargetsResolve) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState {
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d, cs := getData(ctx, obs)
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if cs != nil {
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return []sdk.CheckState{*cs}
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}
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var failed []string
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var checked int
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for _, r := range d.Records {
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if r.IsNullTarget {
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continue
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}
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checked++
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if len(r.Addresses) == 0 {
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failed = append(failed, fmt.Sprintf("%s (%s)", r.Target, r.ResolveError))
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}
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}
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if checked == 0 {
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return []sdk.CheckState{{Status: sdk.StatusUnknown, Code: "srv_no_targets",
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Message: "No resolvable targets to test."}}
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}
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if len(failed) == 0 {
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return []sdk.CheckState{{Status: sdk.StatusOK, Code: "srv_all_resolve",
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Message: fmt.Sprintf("All %d target(s) resolve.", checked)}}
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}
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return []sdk.CheckState{{Status: sdk.StatusCrit, Code: "srv_resolve_fail",
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Message: fmt.Sprintf("Target(s) failed DNS resolution: %s", strings.Join(failed, "; "))}}
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}
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