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

Question

我正在尝试使Scala播放Web应用程序(RESTful)。我一直在遵循有关SQL连接的播放教程，但是在将具有播放应用程序的容器连接到具有mysql容器的容器时遇到了麻烦。经过大量调试后，我意识到scala应用程序可以在本地运行而不是在docker容器中运行。

来自application.conf的代码

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dockerfile

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只运行sbt clean并运行sbt

数据库dockerfile

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(省略类和导入)->这在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)

当我使用docker-compose up数据库运行数据库并且使用sbt在本地运行play应用程序时，端点正常运行并返回Newspost vector

当我通过docker-compose运行两个应用程序时，我得到了巨大的堆栈跟踪

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$$anon$1: Execution exception[[SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30000ms.]]
spades_1    |   at play.api.http.HttpErrorHandlerExceptions$.throwableToUsefulException(HttpErrorHandler.scala:332)
spades_1    |   at play.api.http.DefaultHttpErrorHandler.onServerError(HttpErrorHandler.scala:251)
spades_1    |   at play.core.server.AkkaHttpServer$$anonfun$2.applyOrElse(AkkaHttpServer.scala:421)
spades_1    |   at play.core.server.AkkaHttpServer$$anonfun$2.applyOrElse(AkkaHttpServer.scala:417)
spades_1    |   at scala.concurrent.impl.Promise$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$1(BatchingExecutor.scala:92)
spades_1    |   at scala.runtime.java8.JFunction0$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.

我已经省略了大部分Scala代码，因为它无法在docker中工作，我认为scala代码本身没有问题。

Answer 1

您应该将应用程序指向其他容器，而不是localhost，这从系统 Angular 来看意味着同一台“机器”(即同一容器):

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

您当然可以使此设置取决于环境，以便该应用程序可以在开发模式和docker-compose模式下工作。