metricsreader, observer: read metrics from backend HTTP API (#597)

Author: djshow832

lib/config/proxy.go

@@ -5,12 +5,15 @@ package config
 
 import (
 	"bytes"
+	"net"
 	"os"
 	"path/filepath"
+	"strings"
 	"time"
 
 	"github.com/BurntSushi/toml"
 	"github.com/pingcap/tiproxy/lib/util/errors"
+	"github.com/pingcap/tiproxy/lib/util/sys"
 )
 
 var (
@@ -201,3 +204,30 @@ func (cfg *Config) ToBytes() ([]byte, error) {
 	err := toml.NewEncoder(b).Encode(cfg)
 	return b.Bytes(), errors.WithStack(err)
 }
+
+func (cfg *Config) GetIPPort() (ip, port, statusPort string, err error) {
+	addrs := strings.Split(cfg.Proxy.Addr, ",")
+	ip, port, err = net.SplitHostPort(addrs[0])
+	if err != nil {
+		err = errors.WithStack(err)
+		return
+	}
+	_, statusPort, err = net.SplitHostPort(cfg.API.Addr)
+	if err != nil {
+		err = errors.WithStack(err)
+		return
+	}
+	// AdvertiseAddr may be a DNS in k8s and certificate SAN typically contains DNS but not IP.
+	if len(cfg.Proxy.AdvertiseAddr) > 0 {
+		ip = cfg.Proxy.AdvertiseAddr
+	} else {
+		// reporting a non unicast IP makes no sense, try to find one
+		// loopback/linklocal-unicast are not global unicast IP, but are valid local unicast IP
+		if pip := net.ParseIP(ip); ip == "" || pip.Equal(net.IPv4bcast) || pip.IsUnspecified() || pip.IsMulticast() {
+			if v := sys.GetGlobalUnicastIP(); v != "" {
+				ip = v
+			}
+		}
+	}
+	return
+}

lib/config/proxy_test.go

@@ -4,11 +4,13 @@
 package config
 
 import (
+	"net"
 	"os"
 	"path/filepath"
 	"testing"
 
 	"github.com/BurntSushi/toml"
+	"github.com/pingcap/tiproxy/lib/util/sys"
 	"github.com/stretchr/testify/require"
 )
 
@@ -125,3 +127,46 @@ func TestProxyCheck(t *testing.T) {
 		tc.post(t, &cfg)
 	}
 }
+
+func TestGetIPPort(t *testing.T) {
+	for _, cas := range []struct {
+		addr          string
+		advertiseAddr string
+		port          string
+		nonUnicast    bool
+	}{
+		{":34", "", "34", true},
+		{"0.0.0.0:34", "", "34", true},
+		{"255.255.255.255:34", "", "34", true},
+		{"239.255.255.255:34", "", "34", true},
+		{"[FF02::1:FF47]:34", "", "34", true},
+		{"127.0.0.1:34", "", "34", false},
+		{"[F02::1:FF47]:34", "", "34", false},
+		{"192.0.0.1:6049", "", "6049", false},
+		{"0.0.0.0:1000", "tc-tiproxy-0.tc-tiproxy-peer.ns.svc", "1000", false},
+	} {
+		cfg := &Config{
+			Proxy: ProxyServer{
+				Addr:          cas.addr,
+				AdvertiseAddr: cas.advertiseAddr,
+			},
+			API: API{
+				Addr: cas.addr,
+			},
+		}
+		ip, port, statusPort, err := cfg.GetIPPort()
+		require.NoError(t, err)
+
+		expectedIP := cas.advertiseAddr
+		if len(expectedIP) == 0 {
+			expectedIP, _, err = net.SplitHostPort(cas.addr)
+			require.NoError(t, err)
+			if cas.nonUnicast {
+				expectedIP = sys.GetGlobalUnicastIP()
+			}
+		}
+		require.Equal(t, expectedIP, ip)
+		require.Equal(t, cas.port, port)
+		require.Equal(t, cas.port, statusPort)
+	}
+}