basic dns probing support

Signed-off-by: Kyle Quest <[email protected]>

Author: kcq

go.mod

@@ -134,6 +134,7 @@ require (
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-shellwords v1.0.12 // indirect
 	github.com/mattn/go-sqlite3 v1.14.22 // indirect
+	github.com/miekg/dns v1.1.59 // indirect
 	github.com/miekg/pkcs11 v1.1.1 // indirect
 	github.com/mistifyio/go-zfs/v3 v3.0.1 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
@@ -187,13 +188,13 @@ require (
 	go.opentelemetry.io/otel/trace v1.22.0 // indirect
 	go.starlark.net v0.0.0-20200306205701-8dd3e2ee1dd5 // indirect
 	golang.org/x/exp v0.0.0-20240222234643-814bf88cf225 // indirect
-	golang.org/x/mod v0.15.0 // indirect
+	golang.org/x/mod v0.16.0 // indirect
 	golang.org/x/oauth2 v0.18.0 // indirect
 	golang.org/x/sync v0.6.0 // indirect
 	golang.org/x/term v0.18.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	golang.org/x/time v0.3.0 // indirect
-	golang.org/x/tools v0.18.0 // indirect
+	golang.org/x/tools v0.19.0 // indirect
 	google.golang.org/appengine v1.6.8 // indirect
 	google.golang.org/genproto v0.0.0-20231211222908-989df2bf70f3 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20231212172506-995d672761c0 // indirect

go.sum

@@ -457,6 +457,8 @@ github.com/mattn/go-tty v0.0.3/go.mod h1:ihxohKRERHTVzN+aSVRwACLCeqIoZAWpoICkkvr
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
 github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
+github.com/miekg/dns v1.1.59 h1:C9EXc/UToRwKLhK5wKU/I4QVsBUc8kE6MkHBkeypWZs=
+github.com/miekg/dns v1.1.59/go.mod h1:nZpewl5p6IvctfgrckopVx2OlSEHPRO/U4SYkRklrEk=
 github.com/miekg/pkcs11 v1.1.1 h1:Ugu9pdy6vAYku5DEpVWVFPYnzV+bxB+iRdbuFSu7TvU=
 github.com/miekg/pkcs11 v1.1.1/go.mod h1:XsNlhZGX73bx86s2hdc/FuaLm2CPZJemRLMA+WTFxgs=
 github.com/mistifyio/go-zfs/v3 v3.0.1 h1:YaoXgBePoMA12+S1u/ddkv+QqxcfiZK4prI6HPnkFiU=
@@ -734,6 +736,8 @@ golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/mod v0.15.0 h1:SernR4v+D55NyBH2QiEQrlBAnj1ECL6AGrA5+dPaMY8=
 golang.org/x/mod v0.15.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
+golang.org/x/mod v0.16.0 h1:QX4fJ0Rr5cPQCF7O9lh9Se4pmwfwskqZfq5moyldzic=
+golang.org/x/mod v0.16.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -866,6 +870,8 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
 golang.org/x/tools v0.18.0 h1:k8NLag8AGHnn+PHbl7g43CtqZAwG60vZkLqgyZgIHgQ=
 golang.org/x/tools v0.18.0/go.mod h1:GL7B4CwcLLeo59yx/9UWWuNOW1n3VZ4f5axWfML7Lcg=
+golang.org/x/tools v0.19.0 h1:tfGCXNR1OsFG+sVdLAitlpjAvD/I6dHDKnYrpEZUHkw=
+golang.org/x/tools v0.19.0/go.mod h1:qoJWxmGSIBmAeriMx19ogtrEPrGtDbPK634QFIcLAhc=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

pkg/app/master/probe/http/custom_probe.go

@@ -27,9 +27,6 @@ const (
 	defaultHTTPPortStr    = "80"
 	defaultHTTPSPortStr   = "443"
 	defaultFastCGIPortStr = "9000"
-
-	//other protocols (todo: refactor)
-	defaultRedisPortStr = "6379"
 )
 
 type ovars = app.OutVars
@@ -392,7 +389,56 @@ func (p *CustomProbe) Start() {
 
 					time.Sleep(1 * time.Second)
 				}
-				continue
+
+				if p.OkCount > 0 {
+					continue
+				}
+			} else if (found && dstPort == defaultDNSPortStr) || port == defaultDNSPortStr {
+				//NOTE: a hacky way to support the DNS protocol
+				//TODO: refactor and have a flag to disable this port-based behavior
+				maxRetryCount := probeRetryCount
+				if p.opts.RetryCount > 0 {
+					maxRetryCount = p.opts.RetryCount
+				}
+
+				for i := 0; i < maxRetryCount; i++ {
+					//NOTE: use 'tcp', but later add support for 'udp' when probes support UDP
+					output, err := dnsPing(context.Background(), p.targetHost, port, true)
+					p.CallCount++
+
+					statusCode := "error"
+					callErrorStr := "none"
+					if err == nil {
+						statusCode = "ok"
+					} else {
+						callErrorStr = err.Error()
+					}
+
+					if p.printState {
+						p.xc.Out.Info("dns.probe.call",
+							ovars{
+								"status":  statusCode,
+								"output":  output,
+								"port":    port,
+								"attempt": i + 1,
+								"error":   callErrorStr,
+								"time":    time.Now().UTC().Format(time.RFC3339),
+							})
+					}
+
+					if err == nil {
+						p.OkCount++
+						break
+					} else {
+						p.ErrCount++
+					}
+
+					time.Sleep(1 * time.Second)
+				}
+
+				if p.OkCount > 0 {
+					continue
+				}
 			}
 
 			//If it's ok stop after the first successful probe pass

pkg/app/master/probe/http/dns.go

@@ -0,0 +1,73 @@
+package http
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/miekg/dns"
+
+	"github.com/mintoolkit/mint/pkg/util/jsonutil"
+)
+
+const (
+	defaultDNSPortStr = "53"
+)
+
+var dnsReqBindVersion = &dns.Msg{
+	MsgHdr: dns.MsgHdr{
+		Id:               dns.Id(),
+		RecursionDesired: true,
+	},
+	Question: []dns.Question{
+		{
+			Name:   dns.Fqdn("version.bind"),
+			Qtype:  dns.TypeTXT,
+			Qclass: dns.ClassCHAOS,
+		},
+	},
+}
+
+var dnsReqWhoami = &dns.Msg{
+	MsgHdr: dns.MsgHdr{
+		Id:               dns.Id(),
+		RecursionDesired: true,
+	},
+	Question: []dns.Question{
+		{
+			Name:   dns.Fqdn("whoami.example.org"),
+			Qtype:  dns.TypeA,
+			Qclass: dns.ClassINET,
+		},
+	},
+}
+
+// all DNS servers should respond to the NS query for the root zone
+var dnsReqRootNS = &dns.Msg{
+	MsgHdr: dns.MsgHdr{
+		Id:               dns.Id(),
+		RecursionDesired: true,
+	},
+	Question: []dns.Question{
+		{
+			Name:   dns.Fqdn("."),
+			Qtype:  dns.TypeNS,
+			Qclass: dns.ClassINET,
+		},
+	},
+}
+
+func dnsPing(ctx context.Context, targetHost string, port string, useTCP bool) (string, error) {
+	addr := fmt.Sprintf("%s:%s", targetHost, port)
+	client := &dns.Client{}
+
+	if useTCP {
+		client.Net = "tcp"
+	}
+
+	resp, _, err := client.ExchangeContext(ctx, dnsReqRootNS, addr)
+	if err != nil {
+		return "", err
+	}
+
+	return jsonutil.ToString(resp), nil
+}

pkg/app/master/probe/http/redis.go

@@ -6,7 +6,10 @@ import (
 	"net"
 )
 
-const redisPingReq = "*1\r\n$4\r\nPING\r\n"
+const (
+	defaultRedisPortStr = "6379"
+	redisPingReq        = "*1\r\n$4\r\nPING\r\n"
+)
 
 func redisPing(targetHost string, port string) (string, error) {
 	addr := fmt.Sprintf("%s:%s", targetHost, port)