testcontainers-extensions

Testcontainers Extensions ClickHouse

Testcontainers ClickHouse Extension with advanced testing capabilities.

Features:

• Container easy run per method, per class, per execution.
• Container easy migration with Flyway / Liquibase.
• Container easy connection injection with asserts.

Dependency :rocket:

Gradle

testImplementation "io.goodforgod:testcontainers-extensions-clickhouse:0.12.1"

Maven

<dependency>
    <groupId>io.goodforgod</groupId>
    <artifactId>testcontainers-extensions-clickhouse</artifactId>
    <version>0.12.1</version>
    <scope>test</scope>
</dependency>

JDBC Driver

ClickHouse works natively with Clickhouse JDBC Driver. Driver must be on classpath, if it is somehow not on your classpath already, don’t forget to add:

Gradle

testRuntimeOnly "com.clickhouse:clickhouse-jdbc:0.7.0"
testRuntimeOnly "com.clickhouse:clickhouse-http-client:0.7.0"

Maven

<dependency>
    <groupId>com.clickhouse</groupId>
    <artifactId>clickhouse-jdbc</artifactId>
    <version>0.7.0</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>com.clickhouse</groupId>
    <artifactId>:clickhouse-http-client</artifactId>
    <version>0.7.0</version>
    <scope>test</scope>
</dependency>

Content

• Usage
• Connection
  • Migration
• Annotation
  • Manual Container
  • Connection
  • External Connection
  • Migration

Usage

Test with container start in PER_RUN mode and migration per method will look like:

@TestcontainersClickhouse(mode = ContainerMode.PER_RUN,
        migration = @Migration(
                engine = Migration.Engines.FLYWAY,
                apply = Migration.Mode.PER_METHOD,
                drop = Migration.Mode.PER_METHOD))
class ExampleTests {

  @ConnectionClickhouse
  private JdbcConnection connection;

  @Test
  void test() {
    connection.execute("INSERT INTO users VALUES(1);");
    var usersFound = connection.queryMany("SELECT * FROM users;", r -> r.getInt(1));
    assertEquals(1, usersFound.size());
  }
}

Connection

JdbcConnection is an abstraction with asserting data in database container and easily manipulate container connection settings. You can inject connection via @ConnectionClickhouse as field or method argument or manually create it from container or manual settings.

class ExampleTests {

    private static final ClickhouseContainer container = new ClickhouseContainer();
    
    @Test
    void test() {
      container.start();
      JdbcConnection connection = JdbcConnection.forContainer(container);
      connection.execute("INSERT INTO users VALUES(1);");
    }
}

Connection Migration

Migrations allow easily migrate database between test executions and drop after tests. You can migrate container via @TestcontainersClickhouse#migration annotation parameter or manually using JdbcConnection.

@TestcontainersClickhouse
class ExampleTests {

    @Test
    void test(@ConnectionClickhouse JdbcConnection connection) {
      connection.migrationEngine(Migration.Engines.FLYWAY).apply("db/migration");
      connection.execute("INSERT INTO users VALUES(1);");
      connection.migrationEngine(Migration.Engines.FLYWAY).drop("db/migration");
    }
}

Available migration engines:

• Flyway
• Liquibase

Annotation

@TestcontainersClickhouse - allow automatically start container with specified image in different modes without the need to configure it.

Available containers modes:

• PER_RUN - start container one time per test execution. (Containers must have same instance, e.g. compare by ==)
• PER_CLASS - start new container each test class.
• PER_METHOD - start new container each test method.

Simple example on how to start container per class, no need to configure container:

@TestcontainersClickhouse(mode = ContainerMode.PER_CLASS)
class ExampleTests {

    @Test
    void test(@ConnectionClickhouse JdbcConnection connection) {
        assertNotNull(connection);
    }
}

That’s all you need.

It is possible to customize image with annotation image parameter.

Image also can be provided from environment variable:

@TestcontainersClickhouse(image = "${MY_IMAGE_ENV|clickhouse/clickhouse-server:24.9-alpine}")
class ExampleTests {

    @Test
    void test() {
        // test
    }
}

Image syntax:

• Image can have static value: clickhouse/clickhouse-server:24.9-alpine
• Image can be provided via environment variable using syntax: ${MY_IMAGE_ENV}
• Image environment variable can have default value if empty using syntax: ${MY_IMAGE_ENV|clickhouse/clickhouse-server:24.9-alpine}

Manual Container

When you need to manually configure container with specific options, you can provide such container as instance that will be used by @TestcontainersClickhouse, this can be done using @ContainerClickhouse annotation for container.

Example:

@TestcontainersClickhouse(mode = ContainerMode.PER_CLASS)
class ExampleTests {

    @ContainerClickhouse
    private static final ClickhouseContainer container = new ClickhouseContainer();
    
    @Test
    void test(@ConnectionClickhouse JdbcConnection connection) {
        // do something
    }
}

Network

In case you want to enable Network.SHARED for containers you can do this using network & shared parameter in annotation:

@TestcontainersClickhouse(network = @Network(shared = true))
class ExampleTests {

  @Test
  void test() {
    // test
  }
}

Default alias will be created by default, even if nothing was specified (depends on implementation).

You can provide also custom alias for container. Alias can be extracted from environment variable also or default value can be provided if environment is missing.

In case specified environment variable is missing default alias will be created:

@TestcontainersClickhouse(network = @Network(alias = "${MY_ALIAS_ENV|my_default_alias}"))
class ExampleTests {

    @Test
    void test() {
        // test
    }
}

Image syntax:

• Image can have static value: my-alias
• Image can be provided via environment variable using syntax: ${MY_ALIAS_ENV}
• Image environment variable can have default value if empty using syntax: ${MY_ALIAS_ENV|my-alias-default}

Annotation Connection

JdbcConnection - can be injected to field or method parameter and used to communicate with running container via @ConnectionClickhouse annotation. JdbcConnection provides connection parameters, useful asserts, checks, etc. for easier testing.

Example:

@TestcontainersClickhouse(mode = ContainerMode.PER_CLASS, image = "clickhouse/clickhouse-server:24.9-alpine")
class ExampleTests {

    @ConnectionClickhouse
    private JdbcConnection connection;

    @Test
    void test() {
        connection.execute("CREATE TABLE users (id INT NOT NULL PRIMARY KEY);");
        connection.execute("INSERT INTO users VALUES(1);");
        connection.assertInserted("INSERT INTO users VALUES(2);");
        var usersFound = connection.queryMany("SELECT * FROM users;", r -> r.getInt(1));
        assertEquals(2, usersFound.size());
        connection.assertQueriesEquals(2, "SELECT * FROM users;");
    }
}

External Connection

In case you want to use some external ClickHouse instance that is running in CI or other place for tests (due to docker limitations or other), you can use special environment variables and extension will use them to propagate connection and no ClickHouse containers will be running in such case.

Special environment variables:

• EXTERNAL_TEST_CLICKHOUSE_JDBC_URL - ClickHouse instance JDBC url.
• EXTERNAL_TEST_CLICKHOUSE_USERNAME - ClickHouse instance username (optional).
• EXTERNAL_TEST_CLICKHOUSE_PASSWORD - ClickHouse instance password (optional).
• EXTERNAL_TEST_CLICKHOUSE_HOST - ClickHouse instance host (optional if JDBC url specified).
• EXTERNAL_TEST_CLICKHOUSE_PORT - ClickHouse instance port (optional if JDBC url specified).
• EXTERNAL_TEST_CLICKHOUSE_DATABASE - ClickHouse instance database (default by default) (optional if JDBC url specified)

Use can use either EXTERNAL_TEST_CLICKHOUSE_JDBC_URL to specify connection with username & password combination or use combination of EXTERNAL_TEST_CLICKHOUSE_HOST & EXTERNAL_TEST_CLICKHOUSE_PORT & EXTERNAL_TEST_CLICKHOUSE_DATABASE.

EXTERNAL_TEST_CLICKHOUSE_JDBC_URL env have higher priority over host & port & database.

Annotation Migration

@Migrations allow easily migrate database between test executions and drop after tests.

Annotation parameters:

• engine - to use for migration.
• apply - parameter configures migration mode.
• drop - configures when to reset/drop/clear database. (Liquibase doesn’t support dropAll command, so database is cleaned with TRUNCATE DATABASE)
• locations - configures locations where migrations are placed.

Available migration engines:

• Flyway
• Liquibase

Given engine is Flyway and migration file named V1__flyway.sql is in resource directory on default path db/migration:

CREATE TABLE IF NOT EXISTS users
(
    id INT NOT NULL PRIMARY KEY
);

Test with container and migration per method will look like:

@TestcontainersClickhouse(mode = ContainerMode.PER_CLASS,
        migration = @Migration(
                engine = Migration.Engines.FLYWAY,
                apply = Migration.Mode.PER_METHOD,
                drop = Migration.Mode.PER_METHOD))
class ExampleTests {

    @Test
    void test(@ConnectionClickhouse JdbcConnection connection) {
        connection.execute("INSERT INTO users VALUES(1);");
        var usersFound = connection.queryMany("SELECT * FROM users;", r -> r.getInt(1));
        assertEquals(1, usersFound.size());
    }
}

License

This project licensed under the Apache License 2.0 - see the LICENSE file for details.

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