Jooq 在通过 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来构建我的Spring启动应用程序，然后将其复制到容器中并触发它。这是它的外观：

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"]

这很简单，它将执行 Gradle，jar 将被添加到 docker 容器中。目前为止，一切都好。一旦提供了数据库，这个 Dockerfile 将在 docker-compose.yml 中使用(应用程序需要数据库才能工作(。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，应用程序映像是在数据库映像准备就绪后以及在 flyway 执行迁移之后最后构建的。我在构建应用程序期间遇到的问题。 因此，一旦 gradle 开始，它将完成它必须做的所有事情。但有一次它需要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。构建爆炸并告诉我：

任务：生成示例JooqSchemaSource 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。为什么？这是我在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:nn' + out.toString())
}
}
}

我很困惑，我不确定我是否理解正在发生的事情。如果我使用 docker-compose 仅自行启动数据库映像，然后从我的终端手动运行 gradle(而不是 docker 的 gradle(，这些类将毫无问题地生成。所以我不知道什么时候从 Dockerfile Jooq 中使用 gradle 找不到数据库。知道吗？ 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，因为也许在容器内联网时，url 会重新命名为容器的名称，但这不起作用。发生的情况是这样的：

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中配置jooq插件时localhost作为数据库主机。

您已经为其他地方的DB_HOST正确设置了环境变量，因此我假设您了解服务的名称是 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。你应该改变

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

自

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

或者，您可以在应用程序服务的环境变量中获取DB的主机，然后从build.gradle读取它：

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