连接到Docker容器中的H2数据库 [英] Connecting to an H2 Database in a Docker Container

问题描述

我有一个基本的Spring Boot Data JPA项目.我要连接的h2数据库位于/tmp/customerdb.h2.db.使用mvn spring-boot:run运行应用程序时，一切正常.该应用程序连接到数据库，添加记录，并将添加的记录打印到控制台.

I have a basic Spring Boot Data JPA project. The h2 database that I'm connecting to is located at /tmp/customerdb.h2.db. When running the application using mvn spring-boot:run everything works fine. The application connects to the database, adds records, and prints the added records to the console.

然后我构建一个docker容器并运行它.码头工人文件看起来像这样:

I then build a docker container, and run it. The docker file looks like this:

FROM java:8
VOLUME /tmp
ADD jpa-docker-1.0.0.jar  app.jar
RUN bash -c 'touch /app.jar'
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar",/app.jar"]

运行容器时，出现以下错误:

When I run the container I get the following error:

2015-06-12 19:25:57.200  WARN 1 --- [           main] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 42102, SQLState: 42S02
2015-06-12 19:25:57.200 ERROR 1 --- [           main] o.h.engine.jdbc.spi.SqlExceptionHelper   : Table "CUSTOMER" not found; SQL statement:

因此，看起来应用程序看不到数据库.连接URL如下所示: spring.datasource.url=jdbc:h2:/tmp/customerdb

So it looks like the application can't see the database. The connection URL looks like this: spring.datasource.url=jdbc:h2:/tmp/customerdb

正如我提到的，在docker容器外运行时，此方法工作正常.我假设Dockerfile VOLUME /tmp中的行在容器内创建了/tmp目录，以及其中包含的所有文件，因此可见数据库，但这似乎无法正常工作.有想法吗?

As I mentioned, this works fine when running outside the docker container. I'm assuming that the line in the Dockerfile VOLUME /tmp creates the /tmp directory inside the container, along with all the files it contains, such that the database is visible, but this seems like it's not working. Thoughts?

TIA， -好吧

推荐答案

您应使用docker 数据卷.运行容器时，请指定参数:

You should use docker data volumes. When running your container you specify the parameter:

-v <host folder>:<container folder> 

通过这种方式，主机上的映射在容器内部

This way, the on the host machine is mapped, inside the container

例如:

docker run -v /tmp:/tmp -d yourcontainer

您在容器内的应用程序查找文件/tmp/customerdb.h2.db，该文件实际上位于db文件实际存在的/tmp/customerdb.h2.db主机上(通常，您可以在来宾和主机上使用不同的路径；在您的示例中恰好主机和来宾文件夹都位于同一位置"/tmp")

Your application inside the container looks for the file /tmp/customerdb.h2.db, which actually is on the host at /tmp/customerdb.h2.db where the db file actually exists (in general you could use different paths on the guest and the host; in your example it just happens that the host and guest folders are both on the same location "/tmp")

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