Merge pull request #104 from connctd/crate

Driver for the Crate.io database

docker-compose.yml

@@ -10,6 +10,7 @@ go-test:
     - postgres
     - mysql
     - cassandra
+    - crate
 go-build:
   <<: *go
   command: sh -c 'go get -v && go build -ldflags ''-s'' -o migrater'
@@ -24,3 +25,5 @@ mysql:
     MYSQL_ALLOW_EMPTY_PASSWORD: "yes"
 cassandra:
   image: cassandra:2.2
+crate:
+  image: crate

driver/crate/README.md

@@ -0,0 +1,15 @@
+# Crate driver
+
+This is a driver for the [Crate](https://crate.io) database. It is based on the Crate
+sql driver by [herenow](https://github.com/herenow/go-crate).
+
+This driver does not use transactions! This is not a limitation of the driver, but a 
+limitation of Crate. So handle situations with failed migrations with care!
+
+## Usage
+
+```bash
+migrate -url http://host:port -path ./db/migrations create add_field_to_table
+migrate -url http://host:port -path ./db/migrations up
+migrate help # for more info
+```

driver/crate/crate.go

@@ -0,0 +1,115 @@
+// Package crate implements a driver for the Crate.io database
+package crate
+
+import (
+	"database/sql"
+	"fmt"
+	"strings"
+
+	_ "github.com/herenow/go-crate"
+	"github.com/mattes/migrate/driver"
+	"github.com/mattes/migrate/file"
+	"github.com/mattes/migrate/migrate/direction"
+)
+
+func init() {
+	driver.RegisterDriver("crate", &Driver{})
+}
+
+type Driver struct {
+	db *sql.DB
+}
+
+const tableName = "schema_migrations"
+
+func (driver *Driver) Initialize(url string) error {
+	url = strings.Replace(url, "crate", "http", 1)
+	db, err := sql.Open("crate", url)
+	if err != nil {
+		return err
+	}
+	if err := db.Ping(); err != nil {
+		return err
+	}
+	driver.db = db
+
+	if err := driver.ensureVersionTableExists(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (driver *Driver) Close() error {
+	if err := driver.db.Close(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (driver *Driver) FilenameExtension() string {
+	return "sql"
+}
+
+func (driver *Driver) Version() (uint64, error) {
+	var version uint64
+	err := driver.db.QueryRow("SELECT version FROM " + tableName + " ORDER BY version DESC LIMIT 1").Scan(&version)
+	switch {
+	case err == sql.ErrNoRows:
+		return 0, nil
+	case err != nil:
+		return 0, err
+	default:
+		return version, nil
+	}
+}
+
+func (driver *Driver) Migrate(f file.File, pipe chan interface{}) {
+	defer close(pipe)
+	pipe <- f
+
+	if err := f.ReadContent(); err != nil {
+		pipe <- err
+		return
+	}
+
+	lines := splitContent(string(f.Content))
+	for _, line := range lines {
+		_, err := driver.db.Exec(line)
+		if err != nil {
+			pipe <- err
+			return
+		}
+	}
+
+	if f.Direction == direction.Up {
+		if _, err := driver.db.Exec("INSERT INTO "+tableName+" (version) VALUES (?)", f.Version); err != nil {
+			pipe <- err
+			return
+		}
+	} else if f.Direction == direction.Down {
+		if _, err := driver.db.Exec("DELETE FROM "+tableName+" WHERE version=?", f.Version); err != nil {
+			pipe <- err
+			return
+		}
+	}
+}
+
+func splitContent(content string) []string {
+	lines := strings.Split(content, ";")
+	resultLines := make([]string, 0, len(lines))
+	for i, line := range lines {
+		line = strings.Replace(lines[i], ";", "", -1)
+		line = strings.TrimSpace(line)
+		if line != "" {
+			resultLines = append(resultLines, line)
+		}
+	}
+	return resultLines
+}
+
+func (driver *Driver) ensureVersionTableExists() error {
+	if _, err := driver.db.Exec(fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s (version INTEGER PRIMARY KEY)", tableName)); err != nil {
+		return err
+	}
+	return nil
+}

driver/crate/crate_test.go

@@ -0,0 +1,111 @@
+package crate
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/mattes/migrate/file"
+	"github.com/mattes/migrate/migrate/direction"
+	pipep "github.com/mattes/migrate/pipe"
+)
+
+func TestContentSplit(t *testing.T) {
+	content := `CREATE TABLE users (user_id STRING primary key, first_name STRING, last_name STRING, email STRING, password_hash STRING) CLUSTERED INTO 3 shards WITH (number_of_replicas = 0);
+CREATE TABLE units (unit_id STRING primary key, name STRING, members array(string)) CLUSTERED INTO 3 shards WITH (number_of_replicas = 0);
+CREATE TABLE available_connectors (technology_id STRING primary key, description STRING, icon STRING, link STRING, configuration_parameters array(object as (name STRING, type STRING))) CLUSTERED INTO 3 shards WITH (number_of_replicas = 0);
+	`
+
+	lines := splitContent(content)
+	if len(lines) != 3 {
+		t.Errorf("Expected 3 lines, but got %d", len(lines))
+	}
+
+	if lines[0] != "CREATE TABLE users (user_id STRING primary key, first_name STRING, last_name STRING, email STRING, password_hash STRING) CLUSTERED INTO 3 shards WITH (number_of_replicas = 0)" {
+		t.Error("Line does not match expected output")
+	}
+
+	if lines[1] != "CREATE TABLE units (unit_id STRING primary key, name STRING, members array(string)) CLUSTERED INTO 3 shards WITH (number_of_replicas = 0)" {
+		t.Error("Line does not match expected output")
+	}
+
+	if lines[2] != "CREATE TABLE available_connectors (technology_id STRING primary key, description STRING, icon STRING, link STRING, configuration_parameters array(object as (name STRING, type STRING))) CLUSTERED INTO 3 shards WITH (number_of_replicas = 0)" {
+		t.Error("Line does not match expected output")
+	}
+}
+
+func TestMigrate(t *testing.T) {
+	host := os.Getenv("CRATE_PORT_4200_TCP_ADDR")
+	port := os.Getenv("CRATE_PORT_4200_TCP_PORT")
+
+	url := fmt.Sprintf("crate://%s:%s", host, port)
+
+	driver := &Driver{}
+
+	if err := driver.Initialize(url); err != nil {
+		t.Fatal(err)
+	}
+
+	successFiles := []file.File{
+		{
+			Path:      "/foobar",
+			FileName:  "001_foobar.up.sql",
+			Version:   1,
+			Name:      "foobar",
+			Direction: direction.Up,
+			Content: []byte(`
+                CREATE TABLE yolo (
+                    id integer primary key,
+                    msg string
+                );
+            `),
+		},
+		{
+			Path:      "/foobar",
+			FileName:  "002_foobar.down.sql",
+			Version:   1,
+			Name:      "foobar",
+			Direction: direction.Down,
+			Content: []byte(`
+                DROP TABLE yolo;
+            `),
+		},
+	}
+
+	failFiles := []file.File{
+		{
+			Path:      "/foobar",
+			FileName:  "002_foobar.up.sql",
+			Version:   2,
+			Name:      "foobar",
+			Direction: direction.Up,
+			Content: []byte(`
+                CREATE TABLE error (
+                    id THIS WILL CAUSE AN ERROR
+                )
+            `),
+		},
+	}
+
+	for _, file := range successFiles {
+		pipe := pipep.New()
+		go driver.Migrate(file, pipe)
+		errs := pipep.ReadErrors(pipe)
+		if len(errs) > 0 {
+			t.Fatal(errs)
+		}
+	}
+
+	for _, file := range failFiles {
+		pipe := pipep.New()
+		go driver.Migrate(file, pipe)
+		errs := pipep.ReadErrors(pipe)
+		if len(errs) == 0 {
+			t.Fatal("Migration should have failed but succeeded")
+		}
+	}
+
+	if err := driver.Close(); err != nil {
+		t.Fatal(err)
+	}
+}

main.go

@@ -13,6 +13,7 @@ import (
 	"github.com/fatih/color"
 	_ "github.com/mattes/migrate/driver/bash"
 	_ "github.com/mattes/migrate/driver/cassandra"
+	_ "github.com/mattes/migrate/driver/crate"
 	_ "github.com/mattes/migrate/driver/mysql"
 	_ "github.com/mattes/migrate/driver/postgres"
 	_ "github.com/mattes/migrate/driver/sqlite3"