[wip] Add MongoDB support

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Migrate Changelog
 
+## v1.3.2 - unreleased
+
+* Mongodb support (credits: @dimag-jfrog)
+
 ## v1.3.1 - 2016-08-16
 
 * make mysql driver aware of SSL certificates for TLS connection by scanning ENV variables (https://github.com/mattes/migrate/pull/117/files)

README.md

@@ -25,6 +25,7 @@ __Features__
  * [Cassandra](https://github.com/gemnasium/migrate/tree/master/driver/cassandra)
  * [SQLite](https://github.com/gemnasium/migrate/tree/master/driver/sqlite3)
  * [MySQL](https://github.com/gemnasium/migrate/tree/master/driver/mysql) ([experimental](https://github.com/mattes/migrate/issues/1#issuecomment-58728186))
+ * [MongoDB](https://github.com/gemnasium/migrate/tree/master/driver/mongodb)
  * Bash (planned)
 
 Need another driver? Just implement the [Driver interface](http://godoc.org/github.com/gemnasium/migrate/driver#Driver) and open a PR.

docker-compose.yml

@@ -10,6 +10,7 @@ go-test:
     - postgres
     - mysql
     - cassandra
+    - mongo
 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
+mongo:
+  image: mongo:3.2.6

driver/mongodb/README.md

@@ -0,0 +1,104 @@
+# MongoDB Driver
+
+* Runs pre-registered Golang methods that receive a single `*mgo.Session` parameter and return `error` on failure.
+* Stores migration version details in collection ``db_migrations``.
+  This collection will be auto-generated.
+* Migrations do not run in transactions, there are no built-in transactions in MongoDB.
+  That means that if a migration fails, it will not be rolled back.
+* There is no out-of-the-box support for command-line interface via terminal.
+
+## Usage in Go
+
+```go
+import "github.com/gemnasium/migrate/migrate"
+
+// Import your migration methods package so that they are registered and available for the MongoDB driver.
+// There is no need to import the MongoDB driver explicitly, as it should already be imported by your migration methods package.
+import _ "my_mongo_db_migrator"
+
+// use synchronous versions of migration functions ...
+allErrors, ok := migrate.UpSync("mongodb://host:port", "./path")
+if !ok {
+  fmt.Println("Oh no ...")
+  // do sth with allErrors slice
+}
+
+// use the asynchronous version of migration functions ...
+pipe := migrate.NewPipe()
+go migrate.Up(pipe, "mongodb://host:port", "./path")
+// pipe is basically just a channel
+// write your own channel listener. see writePipe() in main.go as an example.
+```
+
+## Migration files format
+
+The migration files should have an ".mgo" extension and contain a list of registered methods names.
+
+Migration methods should satisfy the following:
+* They should be exported (their name should start with a capital letter) 
+* Their type should be `func (*mgo.Session) error`
+
+Recommended (but not required) naming conventions for migration methods:
+* Prefix with V<version> : for example V001 for version 1. 
+* Suffix with "_up" or "_down" for up and down migrations correspondingly.
+
+001_first_release.up.mgo
+```
+V001_some_migration_operation_up
+V001_some_other_operation_up
+...
+```
+
+001_first_release.down.mgo
+```
+V001_some_other_operation_down
+V001_some_migration_operation_down
+...
+```
+
+
+## Methods registration
+
+For a detailed example see: [sample_mongodb_migrator.go](https://github.com/gemnasium/migrate/blob/master/driver/mongodb/example/sample_mongdb_migrator.go)
+
+```go
+package my_mongo_db_migrator
+
+import (
+  "github.com/gemnasium/migrate/driver/mongodb"
+  "github.com/gemnasium/migrate/driver/mongodb/gomethods"
+  "gopkg.in/mgo.v2"
+)
+
+// common boilerplate
+type MyMongoDbMigrator struct {
+}
+
+func (r *MyMongoDbMigrator) DbName() string {
+  return "<target_db_name_for_migration>"
+}
+
+var _ mongodb.MethodsReceiver = (*MyMongoDbMigrator)(nil)
+
+func init() {
+  gomethods.RegisterMethodsReceiverForDriver("mongodb", &MyMongoDbMigrator{})
+}
+
+
+// Here goes the application-specific migration logic
+func (r *MyMongoDbMigrator) V001_some_migration_operation_up(session *mgo.Session) error {
+  // do something
+  return nil
+}
+
+func (r *MyMongoDbMigrator) V001_some_migration_operation_down(session *mgo.Session) error {
+  // revert some_migration_operation_up from above
+  return nil
+}
+
+```
+
+## Authors
+
+* Demitry Gershovich, https://github.com/dimag-jfrog
+