Rename and relocate CDC Python examples

Moved the CDC example scripts into the protocol directory and added the .py
suffix. Fixed all references to these scripts.

server/modules/protocol/examples/cdc_schema.go

@@ -0,0 +1,168 @@
+// Copyright (c) 2016 MariaDB Corporation Ab
+//
+// Use of this software is governed by the Business Source License included
+// in the LICENSE.TXT file and at www.mariadb.com/bsl.
+//
+// Change Date: 2019-01-01
+//
+// On the date above, in accordance with the Business Source License, use
+// of this software will be governed by version 2 or later of the General
+// Public License.
+
+package main
+
+import (
+	"database/sql"
+	"encoding/json"
+	"flag"
+	"log"
+	"os"
+	"regexp"
+	"strconv"
+)
+
+import _ "github.com/go-sql-driver/mysql"
+
+var host = flag.String("host", "localhost", "Server address")
+var port = flag.Int("port", 3306, "Server port")
+var user = flag.String("user", "", "Server user")
+var passwd = flag.String("password", "", "Server password")
+var debug = flag.Bool("debug", false, "Debug output")
+
+// Avro field
+type Field struct {
+	Name string `json:"name"`
+	Type string `json:"type"`
+}
+
+// Avro schema
+type Schema struct {
+	Namespace string  `json:"namespace"`
+	Type      string  `json:"type"`
+	Name      string  `json:"name"`
+	Fields    []Field `json:"fields"`
+}
+
+// Debugging output helper function
+func LogObject(obj interface{}) {
+	js, err := json.Marshal(obj)
+	if err != nil {
+		log.Fatal("Failed to parse object: ", err)
+	} else {
+		log.Println("Unsupported type: ", string(js))
+	}
+}
+
+var field_re *regexp.Regexp
+
+// Convert the SQL type to the appropriate Avro type
+func (f *Field) ToAvroType() {
+	f.Type = field_re.ReplaceAllString(f.Type, "")
+	switch f.Type {
+	case "date", "datetime", "time", "timestamp", "year", "tinytext", "text",
+		"mediumtext", "longtext", "char", "varchar", "enum", "set":
+		f.Type = "string"
+	case "tinyblob", "blob", "mediumblob", "longblob", "binary", "varbinary":
+		f.Type = "bytes"
+	case "int", "smallint", "mediumint", "integer", "tinyint", "short",
+		"decimal", "bit":
+		f.Type = "int"
+	case "float":
+		f.Type = "float"
+	case "double":
+		f.Type = "double"
+	case "null":
+		f.Type = "null"
+	case "long", "bigint":
+		f.Type = "long"
+	default:
+		LogObject(f)
+		f.Type = "string"
+	}
+}
+
+// Create and store the Avro schema to disk
+func StoreSchema(db *sql.DB, schema, table string) {
+	file, err := os.Create(schema + "." + table + ".000001.avsc")
+	if err != nil {
+		log.Fatal("Failed to create file:", err)
+	}
+	defer file.Close()
+
+	encoder := json.NewEncoder(file)
+	fields, err := db.Query("DESCRIBE " + schema + "." + table)
+	if err != nil {
+		log.Fatal("Failed to query for description of "+schema+"."+table+": ", err)
+	}
+	defer fields.Close()
+
+	fieldlist := make([]Field, 0, 10)
+
+	for fields.Next() {
+		var field Field
+		var Null, Key, Default, Extra string
+
+		fields.Scan(&field.Name, &field.Type, &Null, &Key, &Default, &Extra)
+		field.ToAvroType()
+		fieldlist = append(fieldlist, field)
+	}
+
+	encoder.Encode(Schema{Namespace: "MaxScaleChangeDataSchema.avro", Type: "record", Name: "ChangeRecord", Fields: fieldlist})
+}
+
+// Main funtion that queries the database for table names
+func main() {
+	var err error
+	field_re, err = regexp.Compile("[(].*")
+	if err != nil {
+		log.Fatal("Error: ", err)
+	}
+
+	flag.Parse()
+
+	var connect_str string = *user + ":" + *passwd + "@tcp(" + *host + ":" + strconv.Itoa(*port) + ")/"
+
+	if *debug {
+		log.Println("Connect string: ", connect_str)
+	}
+
+	db, err := sql.Open("mysql", connect_str)
+	if err != nil {
+		log.Fatal("Failed to open connection to", *host, *port, ":", err)
+	}
+	defer db.Close()
+
+	databases, err := db.Query("SHOW DATABASES")
+	if err != nil {
+		log.Fatal("Failed to query for databases: ", err)
+	}
+	defer databases.Close()
+
+	for databases.Next() {
+		var schemaname string
+		databases.Scan(&schemaname)
+
+		// Skip the system databases
+		switch schemaname {
+		case "mysql", "information_schema", "performance_schema":
+			continue
+		}
+
+		tables, err := db.Query("SHOW TABLES FROM " + schemaname)
+		if err != nil {
+			log.Fatal("Failed to query for tables from "+schemaname+": ", err)
+		}
+		defer tables.Close()
+
+		for tables.Next() {
+			var tablename string
+			tables.Scan(&tablename)
+
+			if *debug {
+				log.Println("Processing", schemaname, ".", tablename)
+			}
+
+			StoreSchema(db, schemaname, tablename)
+		}
+	}
+}