Add 'PostgresServiceConfig.LocalService' which defines service locality.

internal/collector/config.go

@@ -30,6 +30,8 @@ type Config struct {
 
 // PostgresServiceConfig defines Postgres-specific stuff required during collecting Postgres metrics.
 type PostgresServiceConfig struct {
+	// LocalService defines service is running on the local host.
+	LocalService bool
 	// BlockSize defines size of data block Postgres operates.
 	BlockSize uint64
 	// WalSegmentSize defines size of WAL segment Postgres operates.
@@ -57,6 +59,9 @@ func NewPostgresServiceConfig(connStr string) (PostgresServiceConfig, error) {
 		return config, err
 	}
 
+	// Determine is service running locally.
+	config.LocalService = isAddressLocal(pgconfig.Host)
+
 	conn, err := store.NewWithConfig(pgconfig)
 	if err != nil {
 		return config, err
@@ -141,6 +146,14 @@ func NewPostgresServiceConfig(connStr string) (PostgresServiceConfig, error) {
 	return config, nil
 }
 
+// isAddressLocal return true if passed address is local, and return false otherwise.
+func isAddressLocal(addr string) bool {
+	if strings.HasPrefix(addr, "/") || strings.HasPrefix(addr, "127.") || addr == "localhost" {
+		return true
+	}
+	return false
+}
+
 // discoverPgStatStatements discovers pg_stat_statements, what database and schema it is installed.
 func discoverPgStatStatements(connStr string) (bool, string, string, error) {
 	pgconfig, err := pgx.ParseConfig(connStr)

internal/collector/config_test.go

@@ -28,6 +28,24 @@ func TestNewPostgresServiceConfig(t *testing.T) {
 	}
 }
 
+func Test_isAddressLocal(t *testing.T) {
+	testcases := []struct {
+		addr string
+		want bool
+	}{
+		{addr: "127.0.0.1", want: true},
+		{addr: "127.1.2.3", want: true},
+		{addr: "/var/run/postgresql", want: true},
+		{addr: "localhost", want: true},
+		{addr: "", want: false},
+		{addr: "1.2.3.4", want: false},
+	}
+
+	for _, tc := range testcases {
+		assert.Equal(t, tc.want, isAddressLocal(tc.addr))
+	}
+}
+
 func Test_discoverPgStatStatements(t *testing.T) {
 	testcases := []struct {
 		valid   bool