CODEWITHSUNDEEP
javaspringspring-bootamazon-dynamodb
Kiran
Kiran

Reputation: 1197

How to set tableName dynamically using environment variable in spring boot?

I am using AWS ECS to host my application and using DynamoDB for all database operations. So I'll have same database with different table names for different environments. Such as "dev_users" (for Dev env), "test_users" (for Test env), etc.. (This is how our company uses same Dynamo account for different environments)

So I would like to change the "tableName" of the model class using the environment variable passed through "AWS ECS task definition" environment parameters.

For Example.

My Model Class is:

@DynamoDBTable(tableName = "dev_users")
public class User {

Now I need to replace the "dev" with "test" when I deploy my container in test environment. I know I can use

@Value("${DOCKER_ENV:dev}")

to access environment variables. But I'm not sure how to use variables outside the class. Is there any way that I can use the docker env variable to select my table prefix?

My Intent is to use like this:

enter image description here

I know this not possible like this. But is there any other way or work around for this?

Edit 1:

I am working on the Rahul's answer and facing some issues. Before writing the issues, I'll explain the process I followed.

Process:

  1. I have created the beans in my config class (com.myapp.users.config).
  2. As I don't have repositories, I have given my Model class package name as "basePackage" path. (Please check the image)

enter image description here

Check the image for error:

enter image description here

I haven't changed anything in my user model class as beans will replace the name of the DynamoDBTable when the beans got executed. But the table name over riding is happening. Data is pulling from the table name given at the Model Class level only.

What I am missing here?

Upvotes: 14

Views: 16895

Answers (4)

Nilesh Sangvikar
Nilesh Sangvikar

Reputation: 31

I am able to achieve table names prefixed with active profile name.

First added TableNameResolver class as below,

@Component
public class TableNameResolver extends DynamoDBMapperConfig.DefaultTableNameResolver {

private String envProfile;

public TableNameResolver() {}

public TableNameResolver(String envProfile) {
    this.envProfile=envProfile;
}

 @Override
 public String getTableName(Class<?> clazz, DynamoDBMapperConfig config) {
  String stageName = envProfile.concat("_");
  String rawTableName = super.getTableName(clazz, config);
  return stageName.concat(rawTableName);
 }
}

Then i setup DynamoDBMapper bean as below,

@Bean
@Primary
public DynamoDBMapper dynamoDBMapper(AmazonDynamoDB amazonDynamoDB) {

    DynamoDBMapper mapper = new DynamoDBMapper(amazonDynamoDB,new DynamoDBMapperConfig.Builder().withTableNameResolver(new TableNameResolver(envProfile)).build());
     return mapper;
}

Added variable envProfile which is an active profile property value accessed from application.properties file.

@Value("${spring.profiles.active}")
private String envProfile;

Upvotes: 3

hb5fa
hb5fa

Reputation: 339

We have the same issue with regards to the need to change table names during runtime. We are using Spring-data-dynamodb 5.0.2 and the following configuration seems to provide the solutions that we need.

First I annotated my bean accessor

@EnableDynamoDBRepositories(dynamoDBMapperConfigRef = "getDynamoDBMapperConfig", basePackages = "my.company.base.package")

I also setup an environment variable called ENV_PREFIX which is Spring wired via SpEL.

@Value("#{systemProperties['ENV_PREFIX']}")
private String envPrefix;

Then I setup a TableNameOverride bean:

@Bean
public DynamoDBMapperConfig.TableNameOverride getTableNameOverride() {
    return DynamoDBMapperConfig.TableNameOverride.withTableNamePrefix(envPrefix);
}

Finally, I setup the DynamoDBMapperConfig bean using TableNameOverride injection. In 5.0.2, we had to setup a standard DynamoDBTypeConverterFactory in the DynamoDBMapperConfig builder to avoid NPE.:

@Bean
public DynamoDBMapperConfig getDynamoDBMapperConfig(DynamoDBMapperConfig.TableNameOverride tableNameOverride) {
    DynamoDBMapperConfig.Builder builder = new DynamoDBMapperConfig.Builder();
    builder.setTableNameOverride(tableNameOverride);
    builder.setTypeConverterFactory(DynamoDBTypeConverterFactory.standard());
    return builder.build();
}

In hind sight, I could have setup a DynamoDBTypeConverterFactory bean that returns a standard DynamoDBTypeConverterFactory and inject that into the getDynamoDBMapperConfig() method using the DynamoDBMapperConfig builder. But this will also do the job.

Upvotes: 2

Essex Boy
Essex Boy

Reputation: 7950

I up voted the other answer but here is an idea:

Create a base class with all your user details:

@MappedSuperclass
public abstract class AbstractUser {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;
    private String firstName;
    private String lastName;

Create 2 implentations with different table names and spirng profiles:

@Profile(value= {"dev","default"})
@Entity(name = "dev_user")
public class DevUser extends AbstractUser {
}

@Profile(value= {"prod"})
@Entity(name = "prod_user")
public class ProdUser extends AbstractUser {
}

Create a single JPA respository that uses the mapped super classs

public interface UserRepository extends CrudRepository<AbstractUser, Long> {
}

Then switch the implentation with the spring profile

@RunWith(SpringJUnit4ClassRunner.class)
@DataJpaTest
@Transactional
public class UserRepositoryTest {

    @Autowired
    protected DataSource dataSource;

    @BeforeClass
    public static void setUp() {
        System.setProperty("spring.profiles.active", "prod");
    }

    @Test
    public void test1() throws Exception {

        DatabaseMetaData metaData = dataSource.getConnection().getMetaData();
        ResultSet tables = metaData.getTables(null, null, "PROD_USER", new String[] { "TABLE" });
        tables.next();
        assertEquals("PROD_USER", tables.getString("TABLE_NAME"));
    }
}

Upvotes: 0

Rahul Babu
Rahul Babu

Reputation: 790

The table names can be altered via an altered DynamoDBMapperConfig bean.

For your case where you have to Prefix each table with a literal, you can add the bean as such. Here the prefix can be the environment name in your case.

 @Bean
public TableNameOverride tableNameOverrider() {
    String prefix = ... // Use @Value to inject values via Spring or use any logic to define the table prefix
    return TableNameOverride.withTableNamePrefix(prefix);
}

For more details check out the complete details here: https://github.com/derjust/spring-data-dynamodb/wiki/Alter-table-name-during-runtime

Upvotes: 9

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