feat: publish standalone worker

Separate worker packaging and service lifecycle from the control plane.

checks/cdns/master_task.go

@@ -0,0 +1,123 @@
+package cdns
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/miekg/dns"
+)
+
+// Results provides functionality.
+type Results map[string]nameServer
+
+func masterTask(zone string, nameservers map[string]nameServer) (uint, uint, bool, Results) {
+	var numRequests uint
+	success := true
+	addressChannel := make(chan DNSreply)
+	soaChannel := make(chan SOAreply)
+	numNS := uint(0)
+	numAddrNS := uint(0)
+	results := make(Results)
+	for name := range nameservers {
+		if !v6only {
+			go localQuery(addressChannel, name, dns.TypeA)
+		}
+		if !v4only {
+			go localQuery(addressChannel, name, dns.TypeAAAA)
+		}
+		numNS++
+	}
+	if v6only || v4only {
+		numRequests = numNS
+	} else {
+		numRequests = numNS * 2
+	}
+	for i := uint(0); i < numRequests; i++ {
+		addrResult := <-addressChannel
+		addrFamily := "IPv6"
+		if addrResult.qtype == dns.TypeA {
+			addrFamily = "IPv4"
+		}
+		if addrResult.r == nil {
+			// TODO We may have different globalErrMsg is it
+			// works with IPv4 but not IPv6 (it should not happen but it does)
+			nameservers[addrResult.qname] = nameServer{
+				name:         addrResult.qname,
+				ips:          nil,
+				globalErrMsg: fmt.Sprintf("Cannot get the %s address: %s", addrFamily, addrResult.err),
+			}
+			success = false
+		} else {
+			if addrResult.r.Rcode != dns.RcodeSuccess {
+				nameservers[addrResult.qname] = nameServer{
+					name:         addrResult.qname,
+					ips:          nil,
+					globalErrMsg: fmt.Sprintf("Cannot get the %s address: %s", addrFamily, dns.RcodeToString[addrResult.r.Rcode]),
+				}
+				success = false
+			} else {
+				for j := range addrResult.r.Answer {
+					ansa := addrResult.r.Answer[j]
+					var ns string
+					switch a := ansa.(type) {
+					case *dns.A:
+						ns = a.A.String()
+						existing := nameservers[addrResult.qname]
+						nameservers[addrResult.qname] = nameServer{name: addrResult.qname, ips: append(existing.ips, ns)}
+						numAddrNS++
+						go soaQuery(soaChannel, zone, addrResult.qname, ns)
+					case *dns.AAAA:
+						ns = a.AAAA.String()
+						existing2 := nameservers[addrResult.qname]
+						nameservers[addrResult.qname] = nameServer{name: addrResult.qname, ips: append(existing2.ips, ns)}
+						numAddrNS++
+						go soaQuery(soaChannel, zone, addrResult.qname, ns)
+					}
+				}
+			}
+		}
+	}
+	for i := uint(0); i < numAddrNS; i++ {
+		if debug {
+			fmt.Printf("DEBUG Getting result for ns #%d/%d\n", i+1, numAddrNS)
+		}
+		soaResult := <-soaChannel
+		_, present := results[soaResult.name]
+		if !present {
+			results[soaResult.name] = nameServer{
+				name:    soaResult.name,
+				ips:     make([]string, 0),
+				success: make([]bool, 0),
+				errMsg:  make([]string, 0),
+				serial:  make([]uint32, 0),
+				rtts:    make([]time.Duration, 0),
+			}
+		}
+		if !soaResult.retrieved {
+			results[soaResult.name] = nameServer{
+				name:    soaResult.name,
+				ips:     append(results[soaResult.name].ips, soaResult.address),
+				success: append(results[soaResult.name].success, false),
+				errMsg:  append(results[soaResult.name].errMsg, soaResult.msg),
+				serial:  append(results[soaResult.name].serial, 0),
+				rtts:    append(results[soaResult.name].rtts, soaResult.rtt),
+			}
+			success = false
+		} else {
+			results[soaResult.name] = nameServer{
+				name:    soaResult.name,
+				ips:     append(results[soaResult.name].ips, soaResult.address),
+				success: append(results[soaResult.name].success, true),
+				errMsg:  append(results[soaResult.name].errMsg, ""),
+				serial:  append(results[soaResult.name].serial, soaResult.serial),
+				rtts:    append(results[soaResult.name].rtts, soaResult.rtt),
+			}
+		}
+	}
+	for name := range nameservers {
+		if nameservers[name].ips == nil {
+			results[name] = nameservers[name]
+		}
+	}
+	return numNS, numAddrNS, success, results
+}