support mysql custom queries

conf/input.mysql/mysql.toml

@@ -35,3 +35,13 @@ labels = { instance="n9e-10.2.3.4:3306" }
 # tls_key = "/etc/categraf/key.pem"
 ## Use TLS but skip chain & host verification
 # insecure_skip_verify = true
+
+[[instances.queries]]
+mesurement = "users"
+metric_fields = [ "total" ]
+label_fields = [ "product" ]
+# field_to_append = ""
+timeout = "3s"
+request = '''
+select 'n9e' as product, count(*) as total from n9e_v5.users
+'''

inputs/mysql/custom_queries.go

@@ -0,0 +1,116 @@
+package mysql
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"log"
+	"strings"
+	"sync"
+	"time"
+
+	"flashcat.cloud/categraf/inputs"
+	"flashcat.cloud/categraf/pkg/conv"
+	"flashcat.cloud/categraf/pkg/tagx"
+	"github.com/toolkits/pkg/container/list"
+)
+
+func (m *MySQL) gatherCustomQueries(slist *list.SafeList, ins *Instance, db *sql.DB, globalTags map[string]string) {
+	wg := new(sync.WaitGroup)
+	defer wg.Wait()
+
+	for i := 0; i < len(ins.Queries); i++ {
+		wg.Add(1)
+		go m.gatherOneQuery(slist, ins, db, globalTags, wg, ins.Queries[i])
+	}
+}
+
+func (m *MySQL) gatherOneQuery(slist *list.SafeList, ins *Instance, db *sql.DB, globalTags map[string]string, wg *sync.WaitGroup, query QueryConfig) {
+	defer wg.Done()
+
+	timeout := time.Duration(query.Timeout)
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	rows, err := db.QueryContext(ctx, query.Request)
+	if ctx.Err() == context.DeadlineExceeded {
+		log.Println("E! query timeout, request:", query.Request)
+		return
+	}
+
+	if err != nil {
+		log.Println("E! failed to query:", err)
+		return
+	}
+
+	defer rows.Close()
+
+	cols, err := rows.Columns()
+	if err != nil {
+		log.Println("E! failed to get columns:", err)
+		return
+	}
+
+	for rows.Next() {
+		columns := make([]interface{}, len(cols))
+		columnPointers := make([]interface{}, len(cols))
+		for i := range columns {
+			columnPointers[i] = &columns[i]
+		}
+
+		// Scan the result into the column pointers...
+		if err := rows.Scan(columnPointers...); err != nil {
+			log.Println("E! failed to scan:", err)
+			return
+		}
+
+		row := make(map[string]string)
+		for i, colName := range cols {
+			val := columnPointers[i].(*interface{})
+			row[strings.ToLower(colName)] = fmt.Sprint(*val)
+		}
+
+		if err = m.parseRow(row, query, slist, globalTags); err != nil {
+			log.Println("E! failed to parse row:", err, "sql:", query.Request)
+		}
+	}
+}
+
+func (m *MySQL) parseRow(row map[string]string, query QueryConfig, slist *list.SafeList, globalTags map[string]string) error {
+	labels := tagx.Copy(globalTags)
+
+	for _, label := range query.LabelFields {
+		labelValue, has := row[label]
+		if has {
+			labels[label] = strings.Replace(labelValue, " ", "_", -1)
+		}
+	}
+
+	for _, column := range query.MetricFields {
+		value, err := conv.ToFloat64(row[column])
+		if err != nil {
+			log.Println("E! failed to convert field:", column, "value:", value, "error:", err)
+			return err
+		}
+
+		if query.FieldToAppend == "" {
+			slist.PushFront(inputs.NewSample(query.Mesurement+"_"+column, value, labels))
+		} else {
+			suffix := cleanName(row[query.FieldToAppend])
+			slist.PushFront(inputs.NewSample(query.Mesurement+"_"+suffix+"_"+column, value, labels))
+		}
+	}
+
+	return nil
+}
+
+func cleanName(s string) string {
+	s = strings.Replace(s, " ", "_", -1) // Remove spaces
+	s = strings.Replace(s, "(", "", -1)  // Remove open parenthesis
+	s = strings.Replace(s, ")", "", -1)  // Remove close parenthesis
+	s = strings.Replace(s, "/", "", -1)  // Remove forward slashes
+	s = strings.Replace(s, "*", "", -1)  // Remove asterisks
+	s = strings.Replace(s, "%", "percent", -1)
+	s = strings.ToLower(s)
+	return s
+}

inputs/mysql/mysql.go

@@ -19,6 +19,15 @@ import (
 
 const inputName = "mysql"
 
+type QueryConfig struct {
+	Mesurement    string          `toml:"mesurement"`
+	LabelFields   []string        `toml:"label_fields"`
+	MetricFields  []string        `toml:"metric_fields"`
+	FieldToAppend string          `toml:"field_to_append"`
+	Timeout       config.Duration `toml:"timeout"`
+	Request       string          `toml:"request"`
+}
+
 type Instance struct {
 	Address        string `toml:"address"`
 	Username       string `toml:"username"`
@@ -28,6 +37,7 @@ type Instance struct {
 
 	Labels        map[string]string `toml:"labels"`
 	IntervalTimes int64             `toml:"interval_times"`
+	Queries       []QueryConfig     `toml:"queries"`
 
 	ExtraStatusMetrics              bool `toml:"extra_status_metrics"`
 	ExtraInnodbMetrics              bool `toml:"extra_innodb_metrics"`
@@ -228,6 +238,7 @@ func (m *MySQL) gatherOnce(slist *list.SafeList, ins *Instance) {
 	if err = db.Ping(); err != nil {
 		slist.PushFront(inputs.NewSample("up", 0, tags))
 		log.Println("E! failed to ping mysql:", err)
+		return
 	}
 
 	slist.PushFront(inputs.NewSample("up", 1, tags))
@@ -245,4 +256,5 @@ func (m *MySQL) gatherOnce(slist *list.SafeList, ins *Instance) {
 	m.gatherTableSize(slist, ins, db, tags, false)
 	m.gatherTableSize(slist, ins, db, tags, true)
 	m.gatherSlaveStatus(slist, ins, db, tags)
+	m.gatherCustomQueries(slist, ins, db, tags)
 }

inputs/oracle/oracle.go

@@ -36,7 +36,7 @@ type OrclInstance struct {
 type MetricConfig struct {
 	Mesurement       string          `toml:"mesurement"`
 	LabelFields      []string        `toml:"label_fields"`
-	MetricFields     []string        `toml:"metric_fields"` // column_name -> value type(float64, bool, int64)
+	MetricFields     []string        `toml:"metric_fields"`
 	FieldToAppend    string          `toml:"field_to_append"`
 	Timeout          config.Duration `toml:"timeout"`
 	Request          string          `toml:"request"`