c1c98924c3
* Add new plugin: external This plugin works in conjunction with the kubernetes plugin and exports ingress and LB addresses as DNS records. It bypasses backend.go and backend_lookup.go flow because it is not needed. README, tests are implemented. The tests only exercise the unit tests, this has not been tested in any ci. Signed-off-by: Miek Gieben <miek@miek.nl> * Rename to k8s_external Signed-off-by: Miek Gieben <miek@miek.nl> * go gen Signed-off-by: Miek Gieben <miek@miek.nl>
92 lines
2.4 KiB
Go
92 lines
2.4 KiB
Go
package kubernetes
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import (
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"strings"
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"github.com/coredns/coredns/plugin/etcd/msg"
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"github.com/coredns/coredns/plugin/kubernetes/object"
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"github.com/coredns/coredns/plugin/pkg/dnsutil"
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"github.com/coredns/coredns/request"
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"github.com/miekg/dns"
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)
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// External implements the ExternalFunc call from the external plugin.
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// It returns any services matching in the services' ExternalIPs.
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func (k *Kubernetes) External(state request.Request) ([]msg.Service, int) {
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base, _ := dnsutil.TrimZone(state.Name(), state.Zone)
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segs := dns.SplitDomainName(base)
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last := len(segs) - 1
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if last < 0 {
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return nil, dns.RcodeServerFailure
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}
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// We dealing with a fairly normal domain name here, but; we still need to have the service
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// and the namespace:
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// service.namespace.<base>
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//
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// for service (and SRV) you can also say _tcp, and port (i.e. _http), we need those be picked
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// up, unless they are not specified, then we use an internal wildcard.
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port := "*"
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protocol := "*"
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namespace := segs[last]
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if !k.namespaceExposed(namespace) || !k.namespace(namespace) {
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return nil, dns.RcodeNameError
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}
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last--
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if last < 0 {
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return nil, dns.RcodeSuccess
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}
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service := segs[last]
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last--
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if last == 1 {
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protocol = stripUnderscore(segs[last])
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port = stripUnderscore(segs[last-1])
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last -= 2
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}
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if last != -1 {
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// too long
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return nil, dns.RcodeNameError
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}
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idx := object.ServiceKey(service, namespace)
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serviceList := k.APIConn.SvcIndex(idx)
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services := []msg.Service{}
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zonePath := msg.Path(state.Zone, coredns)
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rcode := dns.RcodeNameError
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for _, svc := range serviceList {
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if namespace != svc.Namespace {
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continue
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}
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if service != svc.Name {
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continue
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}
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for _, ip := range svc.ExternalIPs {
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for _, p := range svc.Ports {
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if !(match(port, p.Name) && match(protocol, string(p.Protocol))) {
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continue
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}
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rcode = dns.RcodeSuccess
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s := msg.Service{Host: ip, Port: int(p.Port), TTL: k.ttl}
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s.Key = strings.Join([]string{zonePath, svc.Namespace, svc.Name}, "/")
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services = append(services, s)
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}
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}
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}
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return services, rcode
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}
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// ExternalAddress returns the external service address(es) for the CoreDNS service.
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func (k *Kubernetes) ExternalAddress(state request.Request) []dns.RR {
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// This is probably wrong, because of all the fallback behavior of k.nsAddr, i.e. can get
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// an address that isn't reacheable from outside the cluster.
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rrs := []dns.RR{k.nsAddr()}
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return rrs
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}
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