Jooq通过Dockerfile上的gradle映像触发时无法找到数据库

Question

我有一个Dockerfile，它使用gradle构建我的Spring启动应用程序，就在将其复制到容器并触发它之前。它是这样的：

FROM gradle:5.4.1-jdk8-alpine AS build
COPY --chown=gradle:gradle . /home/gradle/src
WORKDIR /home/gradle/src
RUN gradle build --no-daemon

FROM openjdk:8-jdk-alpine
EXPOSE 8080
RUN mkdir /app
COPY --from=build /home/gradle/src/build/libs/*.jar yurlapp.jar
ENTRYPOINT ["java","-jar" , "/yurlapp.jar"]

非常简单，它将执行Gradle并将jar添加到docker容器中。到目前为止，一切都很好。一旦提供了数据库，该Dockerfile将在docker-compose.yml内部使用（该应用程序需要使用DB）。这就是docker-compose.yml的样子：

version: '2.1'
services:
  yurldb:
    image: postgres:11
    container_name: yurldb
    networks:
      - yunet
    ports:
      - 5432:5432
    environment:
      - POSTGRES_DB=yurldb
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=somepassword
    volumes:
      - ./init.sql:/docker-entrypoint-initdb.d/
      - yudata:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U postgres"]
      interval: 10s
      timeout: 10s
      retries: 5
  flyway:
    image: boxfuse/flyway
    command: -url=jdbc:postgresql://yurldb:5432/yurldb -schemas=public -user=postgres -password=somepassword migrate
    networks:
      - yunet
    volumes:
      - .:/flyway/sql
    depends_on:
      yurldb:
        condition: service_healthy
  yurlapp:
    container_name: yurlapp
    image: javing/yurlapp:0.0.1
    build:
      context: .
      dockerfile: Dockerfile
    networks:
      - yunet
    ports:
      - 8080:8080
    environment:
      - DB_HOST=yurldb #the name of the DB container is used as url
    depends_on:
      yurldb:
        condition: service_healthy
      flyway:
        condition: service_healthy
networks:
  yunet:
volumes:
  yudata:

您可以看到，一旦数据库映像准备就绪以及在flyway执行迁移之后，应用程序映像将最后生成。我在构建应用程序时发生的问题。因此，一旦gradle开始，它将做所有要做的事情。但是在某一时刻，它需要Jooq根据数据库上的现有表自动生成一些类。在这里出了点问题。构建炸毁并告诉我这一点：

[任务：generateSampleJooqSchemaSource失败

FAILURE: Build failed with an exception.

* Where:
Build file '/home/gradle/src/build.gradle' line: 81

* What went wrong:
Execution failed for task ':generateSampleJooqSchemaSource'.
> jOOQ source code generation failed:

  Jun 01, 2020 7:37:39 PM org.jooq.tools.JooqLogger info
  INFO: Initialising properties  : /home/gradle/src/build/tmp/generateSampleJooqSchemaSource/config.xml
  Jun 01, 2020 7:37:39 PM org.jooq.tools.JooqLogger error
  SEVERE: Cannot read /home/gradle/src/build/tmp/generateSampleJooqSchemaSource/config.xml. Error : Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
  org.postgresql.util.PSQLException: Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:285)
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
    at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:211)
    at org.postgresql.Driver.makeConnection(Driver.java:459)
    at org.postgresql.Driver.connect(Driver.java:261)
    at org.jooq.codegen.GenerationTool.run0(GenerationTool.java:342)
    at org.jooq.codegen.GenerationTool.run(GenerationTool.java:221)
    at org.jooq.codegen.GenerationTool.generate(GenerationTool.java:216)
    at org.jooq.codegen.GenerationTool.main(GenerationTool.java:188)
  Caused by: java.net.ConnectException: Connection refused (Connection refused)
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at org.postgresql.core.PGStream.<init>(PGStream.java:81)
    at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:93)
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:197)
    ... 8 more

它说它无法连接到数据库。这是为什么？这是我的build.gradle文件中的Jooq配置

jooq {
    sample(sourceSets.main) {
        jdbc {
            driver = 'org.postgresql.Driver'
            url = 'jdbc:postgresql://localhost:5432/yurldb'
            user = 'postgres'
            password = 'somepassword'
        }
        generator {
            database() {
                name = 'org.jooq.meta.postgres.PostgresDatabase'
                inputSchema = 'public'
                includes = '.*'
            }
            target {
                packageName = 'com.javing.yurl'
                directory = 'build/generated/java'
            }
        }
    }
}

tasks.generateSampleJooqSchemaSource.with {
    def out = new ByteArrayOutputStream()
    javaExecSpec = { JavaExecSpec s ->
        s.standardOutput = out
        s.errorOutput = out
        s.ignoreExitValue = true
        s.jvmArgs '-Xmx512M'
    }
    execResultHandler = { ExecResult r ->
        if (r.exitValue != 0) {
            throw new RuntimeException('jOOQ source code generation failed:\n\n' + out.toString())
        }
    }
}

我非常困惑，我不确定我了解发生了什么。如果我要使用docker-compose单独启动数据库映像，然后从终端手动运行gradle（而不是docker的gradle），则将毫无问题地生成这些类。因此，我不知道何时从Dockerfile中使用gradle时Jooq无法找到数据库。任何的想法？我是否也需要以某种方式从Dockerfile触发Jooq，就像触发gradle一样？有人可以帮我这个忙，我有点受阻。

Answer 1

问题是localhost插件的配置中有jooq。

您已在其他地方正确设置了DB_HOST的环境变量，因此我假设您理解该服务的名称是DNS名称，当它们连接到公共网络时可以用来引用其他服务。您应该更改

url = 'jdbc:postgresql://localhost:5432/yurldb'

到

url = 'jdbc:postgresql://yurldb:5432/yurldb'