Don't load all drivers

.travis.yml

@@ -1,21 +1,17 @@
 language: go
+sudo: required
 
 go:
-  - 1.3
   - 1.4
   - 1.5
-  - tip
-
-addons:
-  postgresql: "9.3"
 
 services:
-  - cassandra
+  - docker
 
-before_script:
-  - >
-      /usr/local/cassandra/bin/cqlsh -e "CREATE KEYSPACE migratetest WITH REPLICATION = {'class': 'SimpleStrategy', 'replication_factor' : 1};"
-  - psql -c 'create database migratetest;' -U postgres
-  - mysql -e 'create database migratetest;'
+before_install:
+    - curl -L https://github.com/docker/compose/releases/download/1.4.2/docker-compose-`uname -s`-`uname -m` > docker-compose
+    - chmod +x docker-compose
+    - sudo mv docker-compose /usr/local/bin
+    - sed -i -e 's/golang/golang:'"$TRAVIS_GO_VERSION"'/' docker-compose.yml
 
-script: go test -p 1 ./...
+script: make test

Dockerfile

@@ -0,0 +1,3 @@
+FROM scratch
+ADD migrate /migrate
+ENTRYPOINT ["/migrate"]

Makefile

@@ -0,0 +1,22 @@
+IMAGE=mattes/migrate
+DCR=docker-compose run --rm
+.PHONY: clean test build release docker-build docker-push run
+
+all: release
+
+clean:
+	rm -f migrate
+
+test:
+	$(DCR) go-test
+
+build:
+	$(DCR) go-build
+
+release: test build docker-build docker-push
+
+docker-build:
+	docker build --rm -t $(IMAGE) .
+
+docker-push:
+	docker push $(IMAGE)

README.md

@@ -78,6 +78,9 @@ See GoDoc here: http://godoc.org/github.com/mattes/migrate/migrate
 ```go
 import "github.com/mattes/migrate/migrate"
 
+// Import any required drivers so that they are registered and available
+import _ "github.com/mattes/migrate/drivers/mysql"
+
 // use synchronous versions of migration functions ...
 allErrors, ok := migrate.UpSync("driver://url", "./path")
 if !ok {

docker-compose.yml

@@ -0,0 +1,26 @@
+go: &go
+  image: golang
+  working_dir: /go/src/github.com/mattes/migrate
+  volumes:
+    - $GOPATH:/go
+go-test:
+  <<: *go
+  command: sh -c 'go get -t -v ./... && go test -v ./...'
+  links:
+    - postgres
+    - mysql
+    - cassandra
+go-build:
+  <<: *go
+  command: sh -c 'go get -v && go build -ldflags ''-s'' -o migrater'
+  environment:
+    CGO_ENABLED: 0
+postgres:
+  image: postgres
+mysql:
+  image: mysql
+  environment:
+    MYSQL_DATABASE: migratetest
+    MYSQL_ALLOW_EMPTY_PASSWORD: yes
+cassandra:
+  image: cassandra

driver/bash/bash.go

@@ -2,8 +2,8 @@
 package bash
 
 import (
+	"github.com/mattes/migrate/driver"
 	"github.com/mattes/migrate/file"
-	_ "github.com/mattes/migrate/migrate/direction"
 )
 
 type Driver struct {
@@ -30,3 +30,7 @@ func (driver *Driver) Migrate(f file.File, pipe chan interface{}) {
 func (driver *Driver) Version() (uint64, error) {
 	return uint64(0), nil
 }
+
+func init() {
+	driver.RegisterDriver("bash", &Driver{})
+}

driver/bash/bash_test.go

@@ -1,8 +1,6 @@
 package bash
 
-import (
-	"testing"
-)
+import "testing"
 
 func TestMigrate(t *testing.T) {
 

driver/cassandra/cassandra.go

@@ -3,12 +3,14 @@ package cassandra
 
 import (
 	"fmt"
-	"github.com/gocql/gocql"
-	"github.com/mattes/migrate/file"
-	"github.com/mattes/migrate/migrate/direction"
 	"net/url"
 	"strings"
 	"time"
+
+	"github.com/gocql/gocql"
+	"github.com/mattes/migrate/driver"
+	"github.com/mattes/migrate/file"
+	"github.com/mattes/migrate/migrate/direction"
 )
 
 type Driver struct {
@@ -153,3 +155,7 @@ func (driver *Driver) Version() (uint64, error) {
 	err := driver.session.Query("SELECT version FROM "+tableName+" WHERE versionRow = ?", versionRow).Scan(&version)
 	return uint64(version) - 1, err
 }
+
+func init() {
+	driver.RegisterDriver("cassandra", &Driver{})
+}

driver/cassandra/cassandra_test.go

@@ -2,6 +2,7 @@ package cassandra
 
 import (
 	"net/url"
+	"os"
 	"testing"
 	"time"
 
@@ -13,7 +14,10 @@ import (
 
 func TestMigrate(t *testing.T) {
 	var session *gocql.Session
-	driverUrl := "cassandra://localhost/migratetest"
+
+	host := os.Getenv("CASSANDRA_PORT_9042_TCP_ADDR")
+	port := os.Getenv("CASSANDRA_PORT_9042_TCP_PORT")
+	driverUrl := "cassandra://" + host + ":" + port + "/system"
 
 	// prepare a clean test database
 	u, err := url.Parse(driverUrl)
@@ -32,12 +36,12 @@ func TestMigrate(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if err := session.Query(`DROP TABLE IF EXISTS yolo`).Exec(); err != nil {
-		t.Fatal(err)
-	}
-	if err := session.Query(`DROP TABLE IF EXISTS ` + tableName).Exec(); err != nil {
+	if err := session.Query(`CREATE KEYSPACE IF NOT EXISTS migrate WITH REPLICATION = {'class': 'SimpleStrategy', 'replication_factor': 1};`).Exec(); err != nil {
 		t.Fatal(err)
 	}
+	cluster.Keyspace = "migrate"
+	session, err = cluster.CreateSession()
+	driverUrl = "cassandra://" + host + ":" + port + "/migrate"
 
 	d := &Driver{}
 	if err := d.Initialize(driverUrl); err != nil {

driver/driver.go

@@ -5,22 +5,9 @@ import (
 	"fmt"
 	neturl "net/url" // alias to allow `url string` func signature in New
 
-	"github.com/mattes/migrate/driver/bash"
-	"github.com/mattes/migrate/driver/cassandra"
-	"github.com/mattes/migrate/driver/mysql"
-	"github.com/mattes/migrate/driver/postgres"
-	"github.com/mattes/migrate/driver/sqlite3"
 	"github.com/mattes/migrate/file"
 )
 
-var driverMap = map[string]Driver{
-	"postgres":  &postgres.Driver{},
-	"mysql":     &mysql.Driver{},
-	"bash":      &bash.Driver{},
-	"cassandra": &cassandra.Driver{},
-	"sqlite3":   &sqlite3.Driver{},
-}
-
 // Driver is the interface type that needs to implemented by all drivers.
 type Driver interface {
 
@@ -54,17 +41,19 @@ func New(url string) (Driver, error) {
 		return nil, err
 	}
 
-	if d, found := driverMap[u.Scheme]; found {
-		verifyFilenameExtension(u.Scheme, d)
-		if err := d.Initialize(url); err != nil {
-			return nil, err
-		}
-		return d, nil
+	d := GetDriver(u.Scheme)
+	if d == nil {
+		return nil, fmt.Errorf("Driver '%s' not found.", u.Scheme)
 	}
-	return nil, fmt.Errorf("Driver '%s' not found.", u.Scheme)
+	verifyFilenameExtension(u.Scheme, d)
+	if err := d.Initialize(url); err != nil {
+		return nil, err
+	}
+
+	return d, nil
 }
 
-// verifyFilenameExtension panics if the drivers filename extension
+// verifyFilenameExtension panics if the driver's filename extension
 // is not correct or empty.
 func verifyFilenameExtension(driverName string, d Driver) {
 	f := d.FilenameExtension()

driver/mysql/mysql.go

@@ -7,12 +7,14 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
-	"github.com/go-sql-driver/mysql"
-	"github.com/mattes/migrate/file"
-	"github.com/mattes/migrate/migrate/direction"
 	"regexp"
 	"strconv"
 	"strings"
+
+	"github.com/go-sql-driver/mysql"
+	"github.com/mattes/migrate/driver"
+	"github.com/mattes/migrate/file"
+	"github.com/mattes/migrate/migrate/direction"
 )
 
 type Driver struct {
@@ -177,3 +179,7 @@ func (driver *Driver) Version() (uint64, error) {
 		return version, nil
 	}
 }
+
+func init() {
+	driver.RegisterDriver("mysql", &Driver{})
+}

driver/mysql/mysql_test.go

@@ -2,17 +2,21 @@ package mysql
 
 import (
 	"database/sql"
+	"os"
+	"strings"
+	"testing"
+
 	"github.com/mattes/migrate/file"
 	"github.com/mattes/migrate/migrate/direction"
 	pipep "github.com/mattes/migrate/pipe"
-	"strings"
-	"testing"
 )
 
 // TestMigrate runs some additional tests on Migrate().
 // Basic testing is already done in migrate/migrate_test.go
 func TestMigrate(t *testing.T) {
-	driverUrl := "mysql://root@tcp(127.0.0.1:3306)/migratetest"
+	host := os.Getenv("MYSQL_PORT_3306_TCP_ADDR")
+	port := os.Getenv("MYSQL_PORT_3306_TCP_PORT")
+	driverUrl := "mysql://root@tcp(" + host + ":" + port + ")/migratetest"
 
 	// prepare clean database
 	connection, err := sql.Open("mysql", strings.SplitN(driverUrl, "mysql://", 2)[1])

driver/postgres/postgres.go

@@ -5,10 +5,12 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"strconv"
+
 	"github.com/lib/pq"
+	"github.com/mattes/migrate/driver"
 	"github.com/mattes/migrate/file"
 	"github.com/mattes/migrate/migrate/direction"
-	"strconv"
 )
 
 type Driver struct {
@@ -119,3 +121,7 @@ func (driver *Driver) Version() (uint64, error) {
 		return version, nil
 	}
 }
+
+func init() {
+	driver.RegisterDriver("postgres", &Driver{})
+}

driver/postgres/postgres_test.go

@@ -2,16 +2,20 @@ package postgres
 
 import (
 	"database/sql"
+	"os"
+	"testing"
+
 	"github.com/mattes/migrate/file"
 	"github.com/mattes/migrate/migrate/direction"
 	pipep "github.com/mattes/migrate/pipe"
-	"testing"
 )
 
 // TestMigrate runs some additional tests on Migrate().
 // Basic testing is already done in migrate/migrate_test.go
 func TestMigrate(t *testing.T) {
-	driverUrl := "postgres://localhost/migratetest?sslmode=disable"
+	host := os.Getenv("POSTGRES_PORT_5432_TCP_ADDR")
+	port := os.Getenv("POSTGRES_PORT_5432_TCP_PORT")
+	driverUrl := "postgres://postgres@" + host + ":" + port + "/template1?sslmode=disable"
 
 	// prepare clean database
 	connection, err := sql.Open("postgres", driverUrl)