sync-diff-inspector: add default outputDir and support to export the template config (#553)

close #570

Author: Leavrth

sync_diff_inspector/config/config.go

@@ -22,6 +22,7 @@ import (
 	"os"
 	"path/filepath"
 	"syscall"
+	"time"
 
 	"github.com/BurntSushi/toml"
 	"github.com/pingcap/errors"
@@ -179,9 +180,12 @@ func (t *TaskConfig) Init(
 		return errors.Trace(err)
 	}
 
-	// Create output Dir if not exists
+	// Set default value when output is empty
 	if t.OutputDir == "" {
-		return errors.New("output-dir is missing from the task configuration")
+		t.OutputDir = timestampOutputDir()
+		if err := os.RemoveAll(t.OutputDir); err != nil && !os.IsNotExist(err) {
+			log.Fatal("fail to remove the temp directory", zap.String("path", t.OutputDir), zap.String("error", err.Error()))
+		}
 	}
 
 	ok, err = pathExists(t.OutputDir)
@@ -292,6 +296,9 @@ type Config struct {
 	// config file
 	ConfigFile string
 
+	// export a template config file in the current directory
+	Template string `toml:"-" json:"-"`
+
 	// print version if set true
 	PrintVersion bool
 }
@@ -305,6 +312,7 @@ func NewConfig() *Config {
 	fs.BoolVarP(&cfg.PrintVersion, "version", "V", false, "print version of sync_diff_inspector")
 	fs.StringVarP(&cfg.LogLevel, "log-level", "L", "info", "log level: debug, info, warn, error, fatal")
 	fs.StringVarP(&cfg.ConfigFile, "config", "C", "", "Config file")
+	fs.StringVarP(&cfg.Template, "template", "T", "", "<dm|norm> export a template config file in the current directory")
 	fs.StringVar(&cfg.DMAddr, "dm-addr", "", "the address of DM")
 	fs.StringVar(&cfg.DMTask, "dm-task", "", "identifier of dm task")
 	fs.IntVar(&cfg.CheckThreadCount, "check-thread-count", 1, "how many goroutines are created to check data")
@@ -327,6 +335,10 @@ func (c *Config) Parse(arguments []string) error {
 		return nil
 	}
 
+	if c.Template != "" {
+		return nil
+	}
+
 	// Load config file if specified.
 	if c.ConfigFile == "" {
 		return errors.Errorf("argument --config is required")
@@ -475,6 +487,10 @@ func (c *Config) CheckConfig() bool {
 	return true
 }
 
+func timestampOutputDir() string {
+	return filepath.Join(os.TempDir(), time.Now().Format("sync-diff.output.2006-01-02T15.04.05Z0700"))
+}
+
 func pathExists(_path string) (bool, error) {
 	_, err := os.Stat(_path)
 	if err != nil {

sync_diff_inspector/config/template.go

@@ -0,0 +1,122 @@
+// Copyright 2021 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"fmt"
+
+	"github.com/pingcap/errors"
+)
+
+const (
+	dmConfig = `# Diff Configuration.
+
+######################### Global config #########################
+
+check-thread-count = 4
+
+export-fix-sql = true
+
+check-struct-only = false
+
+dm-addr = "http://127.0.0.1:8261"
+
+dm-task = "test"
+
+######################### Task config #########################
+[task]
+	output-dir = "./output"
+
+	target-check-tables = ["hb_test.*"]
+
+`
+
+	normConfig = `# Diff Configuration.
+
+######################### Global config #########################
+
+check-thread-count = 4
+
+export-fix-sql = true
+
+check-struct-only = false
+
+
+######################### Datasource config #########################
+[data-sources]
+[data-sources.mysql1]
+	host = "127.0.0.1"
+	port = 3306
+	user = "root"
+	password = ""
+
+	route-rules = ["rule1", "rule2"]
+
+[data-sources.tidb0]
+	host = "127.0.0.1"
+	port = 4000
+	user = "root"
+	password = ""
+
+	# snapshot = "386902609362944000"
+
+########################### Routes ###########################
+[routes]
+[routes.rule1]
+schema-pattern = "test_*"
+table-pattern = "t_*"
+target-schema = "test"
+target-table = "t"
+
+[routes.rule2]
+schema-pattern = "test2_*"
+table-pattern = "t2_*"
+target-schema = "test2"
+target-table = "t2"
+
+######################### Task config #########################
+[task]
+	output-dir = "./output"
+
+	source-instances = ["mysql1"]
+
+	target-instance = "tidb0"
+
+	target-check-tables = ["schema*.table*", "!c.*", "test2.t2"]
+
+	target-configs = ["config1"]
+
+######################### Table config #########################
+[table-configs.config1]
+target-tables = ["schema*.test*", "test2.t2"]
+range = "age > 10 AND age < 20"
+index-fields = ["col1","col2"]
+ignore-columns = ["",""]
+chunk-size = 0
+collation = ""
+
+`
+)
+
+func ExportTemplateConfig(configType string) error {
+	switch configType {
+	case "dm", "DM", "Dm", "dM":
+		fmt.Print(dmConfig)
+	case "norm", "normal", "Norm", "Normal":
+		fmt.Print(normConfig)
+	default:
+		return errors.Errorf("Error: unexpect template name: %s\n-T dm: export a dm config\n-T norm: export a normal config\n", configType)
+	}
+	return nil
+}

sync_diff_inspector/main.go

@@ -64,6 +64,14 @@ func main() {
 		return
 	}
 
+	if cfg.Template != "" {
+		if err := config.ExportTemplateConfig(cfg.Template); err != nil {
+			fmt.Printf("%s\n", err.Error())
+			os.Exit(2)
+		}
+		return
+	}
+
 	conf := new(log.Config)
 	conf.Level = cfg.LogLevel