TestContainers：容器之间的通信＆＃x2B;映射在港口外

Question

我有这样的测试设置：

1. myService连接到postgtresql
2. myService endpoint从test Suite中调用了

myService and 和<代码> PostgreSQL 正在使用TestContainers运行。

这是我要实现的网络模式。

起初，我试图通过暴露端口来安排通信。

static final PostgreSQLContainer<?> postgres =
            new PostgreSQLContainer<>(DockerImageName.parse(POSTGRES_VERSION));

static final GenericContainer<?> myService = new GenericContainer<>(DockerImageName.parse(MY_SERVICE_IMAGE))
                .withEnv(
                    Map.of(
                        "SPRING_DATASOURCE_URL", postgres.getJdbcUrl(),
                        "SPRING_DATASOURCE_USERNAME", postgres.getUsername(),
                        "SPRING_DATASOURCE_PASSWORD", postgres.getPassword()
                    )
                )
                .withExposedPorts(8080)
                .withLogConsumer(new Slf4jLogConsumer(LoggerFactory.getLogger("MyService")))

根据logs myService无法建立与PostgreSQL的连接。

Caused by: java.net.ConnectException: Connection refused

然后，我配置了两种服务以共享同一网络。

static final Network SHARED_NETWORK = Network.newNetwork();

static final PostgreSQLContainer<?> postgres =
            new PostgreSQLContainer<>(DockerImageName.parse(POSTGRES_VERSION))
                 .withNetwork(SHARED_NETWORK)
                 .withNetworkAliases("postgres");

static final GenericContainer<?> myService = new GenericContainer<>(DockerImageName.parse(MY_SERVICE_IMAGE))
                .withEnv(
                    Map.of(
                        "SPRING_DATASOURCE_URL", "jdbc:postgresql://postgres:5432/" + postgres.getDatabaseName(),
                        "SPRING_DATASOURCE_USERNAME", postgres.getUsername(),
                        "SPRING_DATASOURCE_PASSWORD", postgres.getPassword()
                    )
                )
                .withExposedPorts(8080)
                .withNetwork(SHARED_NETWORK)
                .withNetworkAliases("MyService")
                .withLogConsumer(new Slf4jLogConsumer(LoggerFactory.getLogger("MyService")))

现在MyService成功地与PostgreSQL 建立了连接。但是，当我从测试套件中执行myService的http请求时，我会遇到相同的错误。

restTemplate.getForObject("http://" + myService.getHost() + ":" + myService.getMappedPort(8080) +"/api/endpoint", Void.class)

Caused by: java.net.ConnectException: Connection refused

我的问题是如何设置容器网络以使该体系结构起作用？

Answer 1

您需要指定端口绑定以将端口暴露于“外部世界”。

与您想要的类似的示例：

  Network network = Network.newNetwork();
  GenericContainer mariaDbServer = getMariaDbContainer(network);
  GenericContainer flywayRunner = getFlywayContainer(network);
  ...
  @SuppressWarnings("rawtypes")
  private GenericContainer getMariaDbContainer(Network network) {

    return new GenericContainer<>("mariadb:10.4.21-focal")
        .withEnv(Map.of("MYSQL_ROOT_PASSWORD", "password", "MYSQL_DATABASE", "somedatabase"))
        .withCommand(
            "mysqld", "--default-authentication-plugin=mysql_native_password", "--character-set-server=utf8mb4",
            "--collation-server=utf8mb4_unicode_ci").withNetwork(network).withNetworkAliases("somedatabasedb")
        .withNetworkMode(network.getId())
        .withExposedPorts(3306).withCreateContainerCmdModifier(
            cmd -> cmd.withNetworkMode(network.getId()).withHostConfig(
                    new HostConfig()
                        .withPortBindings(new PortBinding(Ports.Binding.bindPort(20306), new ExposedPort(3306))))
                .withNetworkMode(network.getId())).withStartupTimeout(Duration.ofMinutes(2L));
  }

  @SuppressWarnings("rawtypes")
  private GenericContainer getFlywayContainer(Network network) {

    return new GenericContainer<>("flyway/flyway:7.15.0-alpine")
        .withEnv(Map.of("MYSQL_ROOT_PASSWORD", "password", "MYSQL_DATABASE", "somedatabase"))
        .withCommand(
            "-url=jdbc:mariadb://somedatabasedb -schemas=somedatabase-user=root -password=password -connectRetries=300 migrate")
        .withFileSystemBind(Paths.get(".", "infrastructure/database/schema").toAbsolutePath().toString(),
            "/flyway/sql", BindMode.READ_ONLY).withNetwork(network).waitingFor(
            Wait.forLogMessage(".*Successfully applied.*", 1)
        ).withStartupTimeout(Duration.of(60, ChronoUnit.SECONDS));
  }

两个容器使用“内部”端口与容器一通信。

容器One将20306（重定向到3306）端口公开到“外界”。

Answer 2

Docker自定义网络具有自己的DNS，您无法使用外部网络的DNS。默认的主机网络共享外部和内部网络的DNS，但有一些缺点。要将数据库容器连接到服务容器，您可以使用- 网络-Alias将Docker转换为IP（ https://docs.docker.com/get-started/07_multi_container/ ）。例如：

 postgres = new PostgreSQLContainer<>("postgres:15")
            .withDatabaseName("cars")
            .withUsername("cars")
            .withPassword("cars")
            .withNetwork(network)
            .withNetworkAliases(“database”)
            .withLogConsumer(new Slf4jLogConsumer(log));
    postgres.start(); 

carsModelsService = new GenericContainer<>("cars/car-models-service-core:latest")
            .withExposedPorts(8180)
            .withNetwork(network)
            .withEnv("POSTGRES_HOST", “database”)
            .dependsOn(postgres)
            .withLogConsumer(new Slf4jLogConsumer(log));
    carsModelsService.start();

where：

application.yml

spring:
  datasource:
    driver-class-name: org.postgresql.Driver
    url: jdbc:postgresql://${POSTGRES_HOST}:5432/cars
    username: cars
    password: cars