docker 容器中运行时，Scala Play JDBC 无法连接到 MySQL

Question

我正在尝试制作一个 scala play 网络应用程序 (RESTful)。我一直在关注 SQL 连接的播放教程，但我无法将带有播放应用程序的容器连接到带有 mysql 容器的容器。经过大量调试后，我意识到当运行在本地而不是在 docker 容器中时，scala 应用程序确实可以工作。

代码来自 application.conf

db.default.driver=com.mysql.cj.jdbc.Driver
db.default.url="jdbc:mysql://localhost:49160/testdb"
db.default.username="root"
db.default.password="password"
db.default.host="localhost"

# db connections = ((pyhsical_core_count * 2) + effective_spindle_count)
fixedConnectionPool = 17

database.dispatcher {
  executor = "thread-pool-executor"
  throughput = 1
  thread-pool-executor {
    fixed-pool-size = ${fixedConnectionPool}
  }
}

docker-compose.yml

version: "2"

services:
  spades:
    build: ./spades
    depends_on:
      - database
    volumes:
      - ./spades/cardsatra-spades:/home/app
    ports:
      - 49162:9000

  database:
    build: ./database
    ports:
      - 49160:3306
    volumes:
      - ./database/data:/var/lib/mysql:rw

sbt 应用程序 docker文件

ARG OPENJDK_TAG=8u232
FROM openjdk:8u232

ARG SBT_VERSION=1.3.7

# Install sbt
RUN \
  curl -L -o sbt-1.3.7.deb https://dl.bintray.com/sbt/debian/sbt-1.3.7.deb && \
  dpkg -i sbt-1.3.7.deb && \
  rm sbt-1.3.7.deb && \
  apt-get update && \
  apt-get install sbt && \
  sbt sbtVersion

EXPOSE 9000

RUN mkdir /home/app
WORKDIR /home/app
COPY cardsatra-spades/entrypoint.sh .

CMD ["/bin/sh", "/home/app/entrypoint.sh"]

entrypoint.sh 只需运行s sbt clean 和 sbt 运行

数据库docker文件

FROM mysql:8

# ENV MYSQL_DATABASE stormlight
ENV MYSQL_ROOT_PASSWORD password
ENV MYSQL_USER mysql
ENV MYSQL_PASSWORD password 
ENV DATABASE_HOST db

scala 端点（省略了 class 和导入）-> 这是在 GET /news/all 路由上

def doSomething: Future[Vector[Newspost]] = Future {
    db.withConnection { conn =>
      var res: Vector[Newspost] = Vector[Newspost]()

      val statement = conn.createStatement
      val resultSet = statement.executeQuery("SELECT * FROM news")


      while(resultSet.next) {
        val id = resultSet.getInt("id")
        val title = resultSet.getString("title")
        val body = resultSet.getString("body")
        val date = resultSet.getString("date")

        res = res :+ Newspost(id, title, body, date)
      }
      res
    }
  }(dec)

当我运行使用 docker 构建数据库并使用 sbt 在本地播放应用程序时运行端点正常工作并且 returns Newspost 矢量

当我运行通过 docker 组合两个应用程序时，我得到一个巨大的堆栈跟踪

spades_1    | Getting req!
spades_1    | [error] p.a.h.DefaultHttpErrorHandler - 
spades_1    | 
spades_1    | ! @7emkpm006 - Internal server error, for (GET) [/news/all] ->
spades_1    |  
spades_1    | play.api.http.HttpErrorHandlerExceptions$$anon: Execution exception[[SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30000ms.]]
spades_1    |   at play.api.http.HttpErrorHandlerExceptions$.throwableToUsefulException(HttpErrorHandler.scala:332)
spades_1    |   at play.api.http.DefaultHttpErrorHandler.onServerError(HttpErrorHandler.scala:251)
spades_1    |   at play.core.server.AkkaHttpServer$$anonfun.applyOrElse(AkkaHttpServer.scala:421)
spades_1    |   at play.core.server.AkkaHttpServer$$anonfun.applyOrElse(AkkaHttpServer.scala:417)
spades_1    |   at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:453)
spades_1    |   at akka.dispatch.BatchingExecutor$AbstractBatch.processBatch(BatchingExecutor.scala:55)
spades_1    |   at akka.dispatch.BatchingExecutor$BlockableBatch.$anonfun$run(BatchingExecutor.scala:92)
spades_1    |   at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18)
spades_1    |   at scala.concurrent.BlockContext$.withBlockContext(BlockContext.scala:94)
spades_1    |   at akka.dispatch.BatchingExecutor$BlockableBatch.run(BatchingExecutor.scala:92)
spades_1    | Caused by: java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30000ms.

我省略了大部分 scala 代码，因为它不在 docker 我假设 scala 代码本身没有问题。

Answer 1

您应该将您的应用程序指向另一个容器，而不是 localhost，这意味着从系统的角度来看相同 "machine"（即相同的容器）：

db.default.url="jdbc:mysql://database:49160/testdb"

您当然可以使此设置依赖于环境，以便应用程序在开发模式和 docker-compose 模式下工作。

docker 容器中运行时，Scala Play JDBC 无法连接到 MySQL

Scala Play JDBC can't connect to MySQL when running in a docker container

mysql

scala

docker

jdbc

playframework

docker 容器中 运行 时，Scala Play JDBC 无法连接到 MySQL

Scala Play JDBC can't connect to MySQL when running in a docker container

mysql

scala

docker

jdbc

playframework

docker 容器中运行时，Scala Play JDBC 无法连接到 MySQL