当通过 Dockerfile 上的 gradle 图像触发时，Jooq 无法找到数据库

Question

我有一个 Dockerfile，它使用 gradle 构建我的 Spring 引导应用程序，然后将其复制到容器中并触发它。这是它的样子：

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"]

很简单，它会执行Gradle，然后将jar 添加到docker 容器中。到目前为止，一切都很好。提供数据库后，将在 docker-compose.yml 中使用此 Dockerfile（应用程序需要数据库才能运行）。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:

如您所见，应用程序映像是最后构建的，一旦数据库映像准备就绪，也是在 flyway 执行迁移之后。我在构建应用程序期间遇到的问题。所以一旦 gradle 启动，它就会做所有它必须做的事情。但在某一时刻，它需要 Jooq，根据数据库中现有的表自动生成一些类。在这里出了点问题。构建爆炸并告诉我：

Task :generateSampleJooqSchemaSource FAILED

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())
        }
    }
}

我很困惑，我不确定我明白发生了什么。如果我要使用 docker-compose 来单独启动数据库映像，然后我从我的终端手动运行 gradle（不是 [=41 中的 gradle =]), 那些类将毫无问题地生成。所以我不知道什么时候从 Dockerfile 使用 gradle Jooq 找不到数据库。任何的想法？我是否还需要以某种方式从 Dockerfile 中触发 Jooq，就像我触发 gradle 一样？有人可以帮我解决这个问题吗，我有点卡住了。

更新我尝试将 jooq 配置中的 url 更改为使用 yurldb 而不是 localhost，因为可能在容器内联网时 url 重新定位到容器的名称，但那没有不工作。这是怎么回事：

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 8:29:57 PM org.jooq.tools.JooqLogger info
  INFO: Initialising properties  : /home/gradle/src/build/tmp/generateSampleJooqSchemaSource/config.xml
  Jun 01, 2020 8:30:08 PM org.jooq.tools.JooqLogger error
  SEVERE: Cannot read /home/gradle/src/build/tmp/generateSampleJooqSchemaSource/config.xml. Error : The connection attempt failed.
  org.postgresql.util.PSQLException: The connection attempt failed.
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:297)
    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.SocketTimeoutException: connect timed out
    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

Answer 1

问题是您在 build.gradle.

中的 jooq 插件配置中将 localhost 作为数据库主机

您已在其他地方为 DB_HOST 正确设置了环境变量，因此我假设您了解服务名称是 DNS 名称，当其他服务连接到公共网络时，您可以使用该名称来引用其他服务网络。你应该改变

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

到

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

或者你可以在应用服务的环境变量中获取db的host，然后从build.gradle中读取它：

def db = System.getenv('DB_HOST')
url = "jdbc:postgresql://${db}:5432/yurldb"

当通过 Dockerfile 上的 gradle 图像触发时，Jooq 无法找到数据库

Jooq unable to find database when triggered via a gradle image on Dockerfile

gradle

flyway

docker

spring-boot

docker-compose