{"record":{"id":"701ac70216ea74e0","repo":"kubernetes/kops","slug":"error-initializing-dns-cache-v","errorCode":null,"errorMessage":"error initializing DNS cache: %v","messagePattern":"error initializing DNS cache: (.+?)","errorType":"console","errorClass":null,"httpStatus":null,"severity":"error","filePath":"dns-controller/pkg/dns/dnscontroller.go","lineNumber":94,"sourceCode":"\n\t// mutex protected the following mutable state\n\tmutex sync.Mutex\n\n\t// Ready is set if the populating controller has performed an initial synchronization of records\n\tReady bool\n\n\t// Records is the map of actual records for this scope\n\tRecords map[string][]Record\n}\n\n// DNSControllerScope is a Scope\nvar _ Scope = &DNSControllerScope{}\n\n// NewDNSController creates a DnsController\nfunc NewDNSController(dnsProviders []dnsprovider.Interface, zoneRules *ZoneRules, updateInterval int) (*DNSController, error) {\n\tdnsCache, err := newDNSCache(dnsProviders)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"error initializing DNS cache: %v\", err)\n\t}\n\n\tc := &DNSController{\n\t\tscopes:         make(map[string]*DNSControllerScope),\n\t\tzoneRules:      zoneRules,\n\t\tdnsCache:       dnsCache,\n\t\tupdateInterval: time.Duration(updateInterval) * time.Second,\n\t}\n\n\treturn c, nil\n}\n\n// Run starts the DnsController.\nfunc (c *DNSController) Run() {\n\tklog.Infof(\"starting DNS controller\")\n\n\tstopCh := c.StopChannel()\n\tgo c.runWatcher(stopCh)","sourceCodeStart":76,"sourceCodeEnd":112,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/dns-controller/pkg/dns/dnscontroller.go#L76-L112","documentation":"NewDNSController initializes the DNS cache via newDNSCache. Any failure there — most commonly a provider not supporting zones (see dnscache.go:45) — is wrapped with 'error initializing DNS cache' and returned, aborting controller construction in main.","triggerScenarios":"Calling NewDNSController with providers where at least one Zones() call fails (returns ok=false) or newDNSCache otherwise errors during construction.","commonSituations":"dns-controller started with a --dns provider lacking zone support; a nil provider slipped into the providers slice; misconfigured provider initialization producing a non-functional interface.","solutions":["Check the wrapped inner error; if it reads 'DNS provider does not support zones', switch --dns to a zone-capable provider.","Verify the providers slice passed to NewDNSController contains only valid, initialized dnsprovider.Interface values.","Confirm provider configuration (flags/env) so provider.Zones() returns a working zones provider."],"exampleFix":"// before\nNewDNSController([]dnsprovider.Interface{unsupported}, zoneRules, 5)\n// after\nproviders, err := dnsprovider.GetDnsProviders(flags.DNS)\nif err != nil { klog.Fatalf(\"dns provider: %v\", err) }\nNewDNSController(providers, zoneRules, 5)","handlingStrategy":"validation","validationCode":"for i, p := range dnsProviders {\n\tif p == nil {\n\t\treturn fmt.Errorf(\"dns provider at index %d is nil\", i)\n\t}\n\tif _, ok := p.Zones(); !ok {\n\t\treturn fmt.Errorf(\"dns provider at index %d (%T) does not support zones\", i, p)\n\t}\n}","typeGuard":"func allProvidersSupportZones(providers []dnsprovider.Interface) bool {\n\tfor _, p := range providers {\n\t\tif p == nil { return false }\n\t\tif _, ok := p.Zones(); !ok { return false }\n\t}\n\treturn len(providers) > 0\n}","tryCatchPattern":"c, err := dns.NewDNSController(providers, zoneRules, interval)\nif err != nil {\n\tklog.Fatalf(\"initializing DNS controller: %v\", err) // read wrapped cause\n}","preventionTips":["Validate all providers support zones before constructing the controller.","Source providers only from dnsprovider.GetDnsProviders with validated flags.","Add a startup smoke test that constructs NewDNSController in CI."],"tags":["dns","dns-controller","initialization","provider"],"backgroundTag":"dns-cache-initialization-failed","analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T07:17:12.445Z"}