mongobee: A Java repository from vbeskrovnov

mongobee is a Java tool which helps you to manage changes in your MongoDB and synchronize them with your application. The concept is very similar to other db migration tools such as Liquibase or Flyway but without using XML/JSON/YML files.

The goal is to keep this tool simple and comfortable to use.

mongobee provides new approach for adding changes (change sets) based on Java classes and methods with appropriate annotations.

Getting started

Add a dependency

With Maven

<dependency>
  <groupId>com.github.mongobee</groupId>
  <artifactId>mongobee</artifactId>
  <version>0.13</version>
</dependency>

With Gradle

compile 'org.javassist:javassist:3.18.2-GA' // workaround for ${javassist.version} placeholder issue*
compile 'com.github.mongobee:mongobee:0.13'

Usage with Spring

You need to instantiate Mongobee object and provide some configuration. If you use Spring can be instantiated as a singleton bean in the Spring context. In this case the migration process will be executed automatically on startup.

@Bean
public Mongobee mongobee(){
  Mongobee runner = new Mongobee("mongodb://YOUR_DB_HOST:27017/DB_NAME");
  runner.setDbName("yourDbName");         // host must be set if not set in URI
  runner.setChangeLogsScanPackage(
       "com.example.yourapp.changelogs"); // the package to be scanned for changesets
  
  return runner;
}

Usage without Spring

Using mongobee without a spring context has similar configuration but you have to remember to run execute() method to start a migration process.

Mongobee runner = new Mongobee("mongodb://YOUR_DB_HOST:27017/DB_NAME");
runner.setDbName("yourDbName");         // host must be set if not set in URI
runner.setChangeLogsScanPackage(
     "com.example.yourapp.changelogs"); // package to scan for changesets

runner.execute();         //  ------> starts migration changesets

Above examples provide minimal configuration. Mongobee object provides some other possibilities (setters) to make the tool more flexible:

runner.setChangelogCollectionName(logColName);   // default is dbchangelog, collection with applied change sets
runner.setLockCollectionName(lockColName);       // default is mongobeelock, collection used during migration process
runner.setEnabled(shouldBeEnabled);              // default is true, migration won't start if set to false

MongoDB URI format:

mongodb://[username:password@]host1[:port1][,host2[:port2],...[,hostN[:portN]]][/[database[.collection]][?options]]

More about URI

Creating change logs

ChangeLog contains bunch of ChangeSets. ChangeSet is a single task (set of instructions made on a database). In other words ChangeLog is a class annotated with @ChangeLog and containing methods annotated with @ChangeSet.

package com.example.yourapp.changelogs;

@ChangeLog
public class DatabaseChangelog {
  
  @ChangeSet(order = "001", id = "someChangeId", author = "testAuthor")
  public void importantWorkToDo(DB db){
     // task implementation
  }


}

@ChangeLog

Class with change sets must be annotated by @ChangeLog. There can be more than one change log class but in that case order argument should be provided:

@ChangeLog(order = "001")
public class DatabaseChangelog {
  //...
}

ChangeLogs are sorted alphabetically by order argument and changesets are applied due to this order.

@ChangeSet

Method annotated by @ChangeSet is taken and applied to the database. History of applied change sets is stored in a collection called dbchangelog (by default) in your MongoDB

Annotation parameters:

order - string for sorting change sets in one changelog. Sorting in alphabetical order, ascending. It can be a number, a date etc.

id - name of a change set, must be unique for all change logs in a database

author - author of a change set

runAlways - [optional, default: false] changeset will always be executed but only first execution event will be stored in dbchangelog collection

Defining ChangeSet methods

Method annotated by @ChangeSet can have one of the following definition:

@ChangeSet(order = "001", id = "someChangeWithoutArgs", author = "testAuthor")
public void someChange1() {
   // method without arguments can do some non-db changes
}

@ChangeSet(order = "002", id = "someChangeWithMongoDatabase", author = "testAuthor")
public void someChange2(MongoDatabase db) {
  // type: com.mongodb.client.MongoDatabase : original MongoDB driver v. 3.x, operations allowed by driver are possible
  // example: 
  MongoCollection<Document> mycollection = db.getCollection("mycollection");
  Document doc = new Document("testName", "example").append("test", "1");
  mycollection.insertOne(doc);
}

@ChangeSet(order = "003", id = "someChangeWithDb", author = "testAuthor")
public void someChange3(DB db) {
  // This is deprecated in mongo-java-driver 3.x, use MongoDatabase instead
  // type: com.mongodb.DB : original MongoDB driver v. 2.x, operations allowed by driver are possible
  // example: 
  DBCollection mycollection = db.getCollection("mycollection");
  BasicDBObject doc = new BasicDBObject().append("test", "1");
  mycollection .insert(doc);
}

@ChangeSet(order = "004", id = "someChangeWithJongo", author = "testAuthor")
public void someChange4(Jongo jongo) {
  // type: org.jongo.Jongo : Jongo driver can be used, used for simpler notation
  // example:
  MongoCollection mycollection = jongo.getCollection("mycollection");
  mycollection.insert("{test : 1}");
}

@ChangeSet(order = "005", id = "someChangeWithSpringDataTemplate", author = "testAuthor")
public void someChange5(MongoTemplate mongoTemplate) {
  // type: org.springframework.data.mongodb.core.MongoTemplate
  // Spring Data integration allows using MongoTemplate in the ChangeSet
  // example:
  mongoTemplate.save(myEntity);
}

@ChangeSet(order = "006", id = "someChangeWithSpringDataTemplate", author = "testAuthor")
public void someChange5(MongoTemplate mongoTemplate, Environment environment) {
  // type: org.springframework.data.mongodb.core.MongoTemplate
  // type: org.springframework.core.env.Environment
  // Spring Data integration allows using MongoTemplate and Environment in the ChangeSet
}

Using Spring profiles

mongobee accepts Spring's org.springframework.context.annotation.Profile annotation. If a change log or change set class is annotated with @Profile, then it is activated for current application profiles.

Example 1: annotated change set will be invoked for a dev profile

@Profile("dev")
@ChangeSet(author = "testuser", id = "myDevChangest", order = "01")
public void devEnvOnly(DB db){
  // ...
}

Example 2: all change sets in a changelog will be invoked for a test profile

@ChangeLog(order = "1")
@Profile("test")
public class ChangelogForTestEnv{
  @ChangeSet(author = "testuser", id = "myTestChangest", order = "01")
  public void testingEnvOnly(DB db){
    // ...
  } 
}

Enabling @Profile annotation (option)

To enable the @Profile integration, please inject org.springframework.core.env.Environment to you runner.

@Bean @Autowired
public Mongobee mongobee(Environment environment) {
  Mongobee runner = new Mongobee(uri);
  runner.setSpringEnvironment(environment)
  //... etc
}

Known issues

Mongo java driver conflicts

mongobee depends on mongo-java-driver. If your application has mongo-java-driver dependency too, there could be a library conflicts in some cases.

Exception:

com.mongodb.WriteConcernException: { "serverUsed" : "localhost" , 
"err" : "invalid ns to index" , "code" : 10096 , "n" : 0 , 
"connectionId" : 955 , "ok" : 1.0}

Workaround:

You can exclude mongo-java-driver from mongobee and use your dependency only. Maven example (pom.xml) below:

<dependency>
    <groupId>org.mongodb</groupId>
    <artifactId>mongo-java-driver</artifactId>
    <version>3.0.0</version>
</dependency>

<dependency>
  <groupId>com.github.mongobee</groupId>
  <artifactId>mongobee</artifactId>
  <version>0.9</version>
  <exclusions>
    <exclusion>
      <groupId>org.mongodb</groupId>
      <artifactId>mongo-java-driver</artifactId>
    </exclusion>
  </exclusions>
</dependency>

vbeskrovnov/mongobee