Fix known mysql type conversion issues (#6647)

plugins/inputs/mysql/mysql.go

@@ -14,6 +14,7 @@ import (
 	"github.com/influxdata/telegraf/internal/tls"
 	"github.com/influxdata/telegraf/plugins/inputs"
 	"github.com/influxdata/telegraf/plugins/inputs/mysql/v1"
+	"github.com/influxdata/telegraf/plugins/inputs/mysql/v2"
 )
 
 type Mysql struct {
@@ -37,6 +38,8 @@ type Mysql struct {
 	GatherPerfEventsStatements          bool     `toml:"gather_perf_events_statements"`
 	IntervalSlow                        string   `toml:"interval_slow"`
 	MetricVersion                       int      `toml:"metric_version"`
+
+	Log telegraf.Logger `toml:"-"`
 	tls.ClientConfig
 	lastT            time.Time
 	initDone         bool
@@ -554,14 +557,20 @@ func (m *Mysql) gatherGlobalVariables(db *sql.DB, serv string, acc telegraf.Accu
 			return err
 		}
 		key = strings.ToLower(key)
+
 		// parse mysql version and put into field and tag
 		if strings.Contains(key, "version") {
 			fields[key] = string(val)
 			tags[key] = string(val)
 		}
-		if value, ok := m.parseValue(val); ok {
+
+		value, err := m.parseGlobalVariables(key, val)
+		if err != nil {
+			m.Log.Debugf("Error parsing global variable %q: %v", key, err)
+		} else {
 			fields[key] = value
 		}
+
 		// Send 20 fields at a time
 		if len(fields) >= 20 {
 			acc.AddFields("mysql_variables", fields, tags)
@@ -575,6 +584,18 @@ func (m *Mysql) gatherGlobalVariables(db *sql.DB, serv string, acc telegraf.Accu
 	return nil
 }
 
+func (m *Mysql) parseGlobalVariables(key string, value sql.RawBytes) (interface{}, error) {
+	if m.MetricVersion < 2 {
+		v, ok := v1.ParseValue(value)
+		if ok {
+			return v, nil
+		}
+		return v, fmt.Errorf("could not parse value: %q", string(value))
+	} else {
+		return v2.ConvertGlobalVariables(key, value)
+	}
+}
+
 // gatherSlaveStatuses can be used to get replication analytics
 // When the server is slave, then it returns only one row.
 // If the multi-source replication is set, then everything works differently
@@ -748,7 +769,10 @@ func (m *Mysql) gatherGlobalStatuses(db *sql.DB, serv string, acc telegraf.Accum
 			}
 		} else {
 			key = strings.ToLower(key)
-			if value, ok := m.parseValue(val); ok {
+			value, err := v2.ConvertGlobalStatus(key, val)
+			if err != nil {
+				m.Log.Debugf("Error parsing global status: %v", err)
+			} else {
 				fields[key] = value
 			}
 		}

plugins/inputs/mysql/v2/convert.go

@@ -0,0 +1,103 @@
+package v2
+
+import (
+	"bytes"
+	"database/sql"
+	"fmt"
+	"strconv"
+)
+
+type ConversionFunc func(value sql.RawBytes) (interface{}, error)
+
+func ParseInt(value sql.RawBytes) (interface{}, error) {
+	v, err := strconv.ParseInt(string(value), 10, 64)
+
+	// Ignore ErrRange.  When this error is set the returned value is "the
+	// maximum magnitude integer of the appropriate bitSize and sign."
+	if err, ok := err.(*strconv.NumError); ok && err.Err == strconv.ErrRange {
+		return v, nil
+	}
+
+	return v, err
+}
+
+func ParseBoolAsInteger(value sql.RawBytes) (interface{}, error) {
+	if bytes.EqualFold(value, []byte("YES")) || bytes.EqualFold(value, []byte("ON")) {
+		return int64(1), nil
+	}
+
+	return int64(0), nil
+}
+
+func ParseGTIDMode(value sql.RawBytes) (interface{}, error) {
+	// https://dev.mysql.com/doc/refman/8.0/en/replication-mode-change-online-concepts.html
+	v := string(value)
+	switch v {
+	case "OFF":
+		return int64(0), nil
+	case "ON":
+		return int64(1), nil
+	case "OFF_PERMISSIVE":
+		return int64(0), nil
+	case "ON_PERMISSIVE":
+		return int64(1), nil
+	default:
+		return nil, fmt.Errorf("unrecognized gtid_mode: %q", v)
+	}
+}
+
+func ParseValue(value sql.RawBytes) (interface{}, error) {
+	if bytes.EqualFold(value, []byte("YES")) || bytes.Compare(value, []byte("ON")) == 0 {
+		return 1, nil
+	}
+
+	if bytes.EqualFold(value, []byte("NO")) || bytes.Compare(value, []byte("OFF")) == 0 {
+		return 0, nil
+	}
+
+	if val, err := strconv.ParseInt(string(value), 10, 64); err == nil {
+		return val, nil
+	}
+	if val, err := strconv.ParseFloat(string(value), 64); err == nil {
+		return val, nil
+	}
+
+	if len(string(value)) > 0 {
+		return string(value), nil
+	}
+
+	return nil, fmt.Errorf("unconvertible value: %q", string(value))
+}
+
+var GlobalStatusConversions = map[string]ConversionFunc{
+	"ssl_ctx_verify_depth": ParseInt,
+	"ssl_verify_depth":     ParseInt,
+}
+
+var GlobalVariableConversions = map[string]ConversionFunc{
+	"gtid_mode": ParseGTIDMode,
+}
+
+func ConvertGlobalStatus(key string, value sql.RawBytes) (interface{}, error) {
+	if bytes.Equal(value, []byte("")) {
+		return nil, nil
+	}
+
+	if conv, ok := GlobalStatusConversions[key]; ok {
+		return conv(value)
+	}
+
+	return ParseValue(value)
+}
+
+func ConvertGlobalVariables(key string, value sql.RawBytes) (interface{}, error) {
+	if bytes.Equal(value, []byte("")) {
+		return nil, nil
+	}
+
+	if conv, ok := GlobalVariableConversions[key]; ok {
+		return conv(value)
+	}
+
+	return ParseValue(value)
+}

plugins/inputs/mysql/v2/convert_test.go

@@ -0,0 +1,86 @@
+package v2
+
+import (
+	"database/sql"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestConvertGlobalStatus(t *testing.T) {
+	tests := []struct {
+		name        string
+		key         string
+		value       sql.RawBytes
+		expected    interface{}
+		expectedErr error
+	}{
+		{
+			name:        "default",
+			key:         "ssl_ctx_verify_depth",
+			value:       []byte("0"),
+			expected:    int64(0),
+			expectedErr: nil,
+		},
+		{
+			name:        "overflow int64",
+			key:         "ssl_ctx_verify_depth",
+			value:       []byte("18446744073709551615"),
+			expected:    int64(9223372036854775807),
+			expectedErr: nil,
+		},
+		{
+			name:        "defined variable but unset",
+			key:         "ssl_ctx_verify_depth",
+			value:       []byte(""),
+			expected:    nil,
+			expectedErr: nil,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual, err := ConvertGlobalStatus(tt.key, tt.value)
+			require.Equal(t, tt.expectedErr, err)
+			require.Equal(t, tt.expected, actual)
+		})
+	}
+}
+
+func TestCovertGlobalVariables(t *testing.T) {
+	tests := []struct {
+		name        string
+		key         string
+		value       sql.RawBytes
+		expected    interface{}
+		expectedErr error
+	}{
+		{
+			name:        "boolean type mysql<=5.6",
+			key:         "gtid_mode",
+			value:       []byte("ON"),
+			expected:    int64(1),
+			expectedErr: nil,
+		},
+		{
+			name:        "enum type mysql>=5.7",
+			key:         "gtid_mode",
+			value:       []byte("ON_PERMISSIVE"),
+			expected:    int64(1),
+			expectedErr: nil,
+		},
+		{
+			name:        "defined variable but unset",
+			key:         "ssl_ctx_verify_depth",
+			value:       []byte(""),
+			expected:    nil,
+			expectedErr: nil,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual, err := ConvertGlobalVariables(tt.key, tt.value)
+			require.Equal(t, tt.expectedErr, err)
+			require.Equal(t, tt.expected, actual)
+		})
+	}
+}