* Removing unnecessary gitignore pattern * Updating Makefile to run unittests for subpackages * Adding Corefile validation to ignore overlapping zones * Fixing SRV query handling * Updating README.md now that SRV works * Fixing debug message, adding code comment * Clarifying implementation of zone normalization * "Overlapping zones" is ill-defined. Reimplemented zone overlap/subzone checking to contain these functions in k8s middleware and provide better code comments explaining the normalization. * Separate build verbosity from test verbosity * Cleaning up comments to match repo code style * Merging warning messages into single message * Moving function docs to before function declaration * Adding test cases for k8sclient connector * Tests cover connector create and setting base url * Fixed bugs in connector create and setting base url functions * Updaing README to group and order development work * Priority focused on achieving functional parity with SkyDNS. * Adding work items to README and cleaning up formatting * More README format cleaning * List formating * Refactoring k8s API call to allow dependency injection * Add test cases for data parsing from k8s into dataobject structures * URL is dependency-injected to allow replacement with a mock http server during test execution * Adding more data validation for JSON parsing tests * Adding test case for GetResourceList() * Adding notes about SkyDNS embedded IP and port record names * Marked test case implemented. * Fixing formatting for example command. * Fixing formatting * Adding notes about Docker image building. * Adding SkyDNS work item * Updating TODO list * Adding name template to Corefile to specify how k8s record names are assembled * Adding template support for multi-segment zones * Updating example CoreFile for k8s with template comment * Misc whitespace cleanup * Adding SkyDNS naming notes * Adding namespace filtering to CoreFile config * Updating example k8sCoreFile to specify namespaces * Removing unused codepath * Adding check for valid namespace * More README TODO restructuring to focus effort * Adding template validation while parsing CoreFile * Record name template is considered invalid if it contains a symbol of the form ${bar} where the symbol "${bar}" is not an accepted template symbol. * Refactoring generation of answer records * Parse typeName out of query string * Refactor answer record creation as operation over list of ServiceItems * Moving k8s API caching into SkyDNS equivalency segment * Adding function to assemble record names from template * Warning: This commit may be broken. Syncing to get laptop code over to dev machine. * More todo notes * Adding comment describing sample test data. * Update k8sCorefile * Adding comment * Adding filtering support for kubernetes "type" * Required refactoring to support reuse of the StringInSlice function. * Cleaning up formatting * Adding note about SkyDNS supporting word "any". * baseUrl -> baseURL * Also removed debug statement from core/setup/kubernetes.go * Fixing test breaking from Url -> URL naming changes * Changing record name template language ${...} -> {...} * Fix formatting with go fmt * Updating all k8sclient data getters to return error value * Adding error message to k8sclient data accessors * Cleaning up setup for kubernetes * Removed verbose nils in initial k8s middleware instance * Set reasonable defaults if CoreFile has no parameters in the kubernetes block. (k8s endpoint, and name template) * Formatting cleanup -- go fmt
104 lines
2.5 KiB
Go
104 lines
2.5 KiB
Go
package kubernetes
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import (
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"fmt"
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"github.com/miekg/coredns/middleware"
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"github.com/miekg/dns"
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"golang.org/x/net/context"
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)
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func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
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fmt.Printf("[debug] here entering ServeDNS: ctx:%v dnsmsg:%v\n", ctx, r)
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state := middleware.State{W: w, Req: r}
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if state.QClass() != dns.ClassINET {
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return dns.RcodeServerFailure, fmt.Errorf("can only deal with ClassINET")
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}
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// Check that query matches one of the zones served by this middleware,
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// otherwise delegate to the next in the pipeline.
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zone := middleware.Zones(k.Zones).Matches(state.Name())
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if zone == "" {
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if k.Next == nil {
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return dns.RcodeServerFailure, nil
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}
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return k.Next.ServeDNS(ctx, w, r)
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}
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m := new(dns.Msg)
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m.SetReply(r)
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m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
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var (
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records, extra []dns.RR
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err error
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)
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switch state.Type() {
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case "A":
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records, err = k.A(zone, state, nil)
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case "AAAA":
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records, err = k.AAAA(zone, state, nil)
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case "TXT":
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records, err = k.TXT(zone, state)
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// TODO: change lookup to return appropriate error. Then add code below
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// this switch to check for the error and return not implemented.
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//return dns.RcodeNotImplemented, nil
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case "CNAME":
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records, err = k.CNAME(zone, state)
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case "MX":
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records, extra, err = k.MX(zone, state)
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case "SRV":
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records, extra, err = k.SRV(zone, state)
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case "SOA":
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records = []dns.RR{k.SOA(zone, state)}
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case "NS":
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if state.Name() == zone {
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records, extra, err = k.NS(zone, state)
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break
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}
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fallthrough
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default:
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// Do a fake A lookup, so we can distinguish betwen NODATA and NXDOMAIN
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_, err = k.A(zone, state, nil)
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}
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if isKubernetesNameError(err) {
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return k.Err(zone, dns.RcodeNameError, state)
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}
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if err != nil {
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return dns.RcodeServerFailure, err
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}
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if len(records) == 0 {
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return k.Err(zone, dns.RcodeSuccess, state)
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}
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m.Answer = append(m.Answer, records...)
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m.Extra = append(m.Extra, extra...)
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m = dedup(m)
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state.SizeAndDo(m)
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m, _ = state.Scrub(m)
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w.WriteMsg(m)
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return dns.RcodeSuccess, nil
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}
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// NoData write a nodata response to the client.
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func (k Kubernetes) Err(zone string, rcode int, state middleware.State) (int, error) {
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m := new(dns.Msg)
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m.SetRcode(state.Req, rcode)
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m.Ns = []dns.RR{k.SOA(zone, state)}
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state.SizeAndDo(m)
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state.W.WriteMsg(m)
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return rcode, nil
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}
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func dedup(m *dns.Msg) *dns.Msg {
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// TODO(miek): expensive!
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m.Answer = dns.Dedup(m.Answer, nil)
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m.Ns = dns.Dedup(m.Ns, nil)
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m.Extra = dns.Dedup(m.Extra, nil)
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return m
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}
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