等待容器端口打開超時（本地主機端口：[32773]應該正在偵聽）

Question

我正在嘗試使用https://www.testcontainers.org/中固有的https://github.com/testcontainers/testcontainers-scala如下：

final class MessageSpec extends BddSpec
  with ForAllTestContainer
  with BeforeAndAfterAll {


  override val container = GenericContainer("sweetsoft/sapmock").configure{ c =>
    c.addExposedPort(8080)
    c.withNetwork(Network.newNetwork())
  }

  override def beforeAll() {
  }


  feature("Process incoming messages") {  

當我使用sbt test命令sbt test ，出現以下異常：

15:22:23.171 [pool-7-thread-2] ERROR 🐳 [sweetsoft/sapmock:latest] - Could not start container
org.testcontainers.containers.ContainerLaunchException: Timed out waiting for container port to open (localhost ports: [32775] should be listening)
        at org.testcontainers.containers.wait.strategy.HostPortWaitStrategy.waitUntilReady(HostPortWaitStrategy.java:47)
        at org.testcontainers.containers.wait.strategy.AbstractWaitStrategy.waitUntilReady(AbstractWaitStrategy.java:35)
        at org.testcontainers.containers.wait.HostPortWaitStrategy.waitUntilReady(HostPortWaitStrategy.java:23)
        at org.testcontainers.containers.wait.strategy.AbstractWaitStrategy.waitUntilReady(AbstractWaitStrategy.java:35)
        at org.testcontainers.containers.GenericContainer.waitUntilContainerStarted(GenericContainer.java:582)

該圖像是本地圖像：

docker images
REPOSITORY                    TAG                 IMAGE ID            CREATED             SIZE
sweetsoft/sapmock             latest              f02be90356e7        3 hours ago         664MB
openjdk                       8                   bec43387959a        11 days ago         625MB
quay.io/testcontainers/ryuk   0.2.3               64849fd2d464        3 months ago        10.7MB

問題是，為什么要等待32775端口？ 對於港口有什么好處？

更新

也許此日志會有所幫助：

15:47:47.274 [pool-7-thread-4] INFO org.testcontainers.dockerclient.DockerClientProviderStrategy - Found Docker environment with Environment variables, system properties and defaults. Resolved: 
    dockerHost=unix:///var/run/docker.sock
    apiVersion='{UNKNOWN_VERSION}'
    registryUrl='https://index.docker.io/v1/'
    registryUsername='developer'
    registryPassword='null'
    registryEmail='null'
    dockerConfig='DefaultDockerClientConfig[dockerHost=unix:///var/run/docker.sock,registryUsername=developer,registryPassword=<null>,registryEmail=<null>,registryUrl=https://index.docker.io/v1/,dockerConfigPath=/home/developer/.docker,sslConfig=<null>,apiVersion={UNKNOWN_VERSION},dockerConfig=<null>]'

15:47:47.275 [pool-7-thread-4] INFO org.testcontainers.DockerClientFactory - Docker host IP address is localhost
15:47:47.277 [pool-7-thread-4] DEBUG com.github.dockerjava.core.command.AbstrDockerCmd - Cmd: com.github.dockerjava.core.exec.InfoCmdExec@51a07bb5
15:47:47.389 [pool-7-thread-4] DEBUG com.github.dockerjava.core.command.AbstrDockerCmd - Cmd: com.github.dockerjava.core.exec.VersionCmdExec@70fc9b37
15:47:47.392 [pool-7-thread-4] INFO org.testcontainers.DockerClientFactory - Connected to docker: 
  Server Version: 18.09.6
  API Version: 1.39
  Operating System: Ubuntu 18.04.2 LTS
  Total Memory: 7976 MB
15:47:47.395 [pool-7-thread-4] DEBUG com.github.dockerjava.core.command.AbstrDockerCmd - Cmd: ListImagesCmdImpl[imageNameFilter=quay.io/testcontainers/ryuk:0.2.3,showAll=false,filters=com.github.dockerjava.core.util.FiltersBuilder@0,execution=com.github.dockerjava.core.exec.ListImagesCmdExec@562a343]
15:47:47.417 [pool-7-thread-4] DEBUG org.testcontainers.utility.RegistryAuthLocator - Looking up auth config for image: quay.io/testcontainers/ryuk:0.2.3
15:47:47.417 [pool-7-thread-4] DEBUG org.testcontainers.utility.RegistryAuthLocator - RegistryAuthLocator has configFile: /home/developer/.docker/config.json (does not exist) and commandPathPrefix: 
15:47:47.418 [pool-7-thread-4] WARN org.testcontainers.utility.RegistryAuthLocator - Failure when attempting to lookup auth config (dockerImageName: quay.io/testcontainers/ryuk:0.2.3, configFile: /home/developer/.docker/config.json. Falling back to docker-java default behaviour. Exception message: /home/developer/.docker/config.json (No such file or directory)
15:47:47.418 [pool-7-thread-4] DEBUG org.testcontainers.dockerclient.auth.AuthDelegatingDockerClientConfig - Effective auth config [null]

Answer 1

原始的Java庫可以回答您的端口問題。
https://www.testcontainers.org/features/networking/

請注意，此暴露的端口號是從容器的角度來看的。

從主機的角度來看，Testcontainer實際上是在隨機的免費端口上公開的。 這是設計使然，以避免本地運行的軟件或並行測試運行之間可能發生的端口沖突。

因為存在此間接層，所以有必要在運行時向Testcontainers詢問實際的映射端口。 可以使用getMappedPort方法完成此操作，該方法將原始（容器）端口作為參數

在Scala庫中，您可以通過調用以下命令獲取此映射端口

container.mappedPort(yourExposedPort) 

錯誤很可能與該概念有關，您需要在Docker映像內預先公開該端口。 確保您在dockerfile中的某個位置expose 8080命令，或者用於構建您的鏡像的任何圖像都有它