在Spring Boot上环境变量和@Value不能一起使用 [英] Environment variables and @Value can't work together on Spring Boot

问题描述

我有一个Spring启动应用程序，该应用程序连接到充当缓存的Redis实例。在开发环境中时，我有以下内容：

I have a Spring boot app that connects to a Redis instance that works as a cache. When I'm in dev environment, I have the following:

---

spring:
  profiles: default
redis: 
  host: localhost
  port: 6379

我的缓存配置类是这样的：

And my cache configuration class is like this:

@Configuration
@EnableCaching
public class CacheConfiguration {

   @Value("${redis.host}") 
   String redisHost;

   @Value("${redis.port}") 
   int redisPort;

在生产中，此应用程序已被Docker化，并且我有以下 docker- compose.yml 文件：

In production, this app is Dockerized, and I have the following docker-compose.yml file:

redis: 
  image: tutum/redis
  ports:
    - "6379:6379"
  volumes:
    - /data
app: 
  build: .
  ports:
    - "8080:8080"
  links:
    - redis

而 application.yml 是：

---

spring:
  profiles: docker
redis: 
  host: redis
  port: 6379

要在Docker上启动应用程序，我需要运行 -Dspring.profiles.active = docker ，但是在应用程序启动时，会发生以下错误：

To start the app on Docker, I run with -Dspring.profiles.active=docker, but when the app is starting up, the following error happens:

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private int com.inkdrop.config.cache.CacheConfiguration.redisPort; nested exception is org.springframework.beans.TypeMismatchException: Failed to convert value of type [java.lang.String] to required type [int]; nested exception is java.lang.NumberFormatException: For input string: "tcp://172.17.0.3:6379"

由于某种原因，Spring Boot将 redis.port 读为 tcp：//172.17.0.3：6379 。因此对于测试建议，我从 CacheConfiguration 类中删除了 @Value 批注，并将其手动设置为 redis 作为主机， 6379 作为端口，它可以正常工作。好像在使用环境变量和 @Value 时，Spring迷路了。有人有想法吗？

For some reason, Spring Boot is reading the redis.port as tcp://172.17.0.3:6379. So for tests proposes, I removed the @Value annotations from CacheConfiguration class, and set it manually to redis as host and 6379 as port and it worked. Seems like when using environment variables and @Value, Spring get lost. Anyone have an idea?

推荐答案

基于 Docker文档：

Compose使用Docker链接公开服务容器到一个
每个链接的容器都会注入一组环境变量，
每个变量都以容器的大写字母开头。

Docker Compose将使用 name_PORT 格式创建表示容器的完整URL 的环境变量，例如 REDIS_PORT = tcp：//172.17.0.5：6379 。

Docker Compose would create an Environment Variable representing the Full URL of the container using name_PORT format, e.g. REDIS_PORT=tcp://172.17.0.5:6379.

并基于您的 docker-compose.yml 文件：

redis: 
  image: tutum/redis
  ports:
    - "6379:6379"
  volumes:
    - /data

您将拥有一个名为 REDIS_PORT 的环境变量，其值等于 tcp：//172.17.0.3：6379 。由于OS环境变量相对于Profile特定的应用程序属性具有更高的优先级，因此Spring Boot会在上使用 REDIS_PORT 值redis.port ，因此出现错误：

You would have an Environment Variable named REDIS_PORT with a value equals to tcp://172.17.0.3:6379.Since OS environment variables have more precedence with respect to Profile-specific application properties, Spring Boot would pick up the REDIS_PORT value over redis.port, hence the error:

原因：org.springframework.beans.factory.BeanCreationException：
无法自动连线字段：private int
com.inkdrop.config.cache.CacheConfiguration.redisPort;嵌套的
异常是org.springframework.beans.TypeMismatchException：
无法将[java.lang.String]类型的值转换为所需的[int]类型；
嵌套异常是java.lang.NumberFormatException：对于输入字符串：
tcp：//172.17.0.3：6379

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private int com.inkdrop.config.cache.CacheConfiguration.redisPort; nested exception is org.springframework.beans.TypeMismatchException: Failed to convert value of type [java.lang.String] to required type [int]; nested exception is java.lang.NumberFormatException: For input string: "tcp://172.17.0.3:6379"

作为解决此问题的方法，您应该使用端口值覆盖 REDIS_PORT 环境变量，或者从 redis重命名配置名称。 .name 到没有争议的地方。

As a workaround for this problem, you either should override the REDIS_PORT environment variable with your port value or rename your config name from redis.name to anything less controversial.

有点麻烦，但只是引用 tutum-docker-redis Github存储库：

Kinda off topic but just quoting from tutum-docker-redis Github repository:

此图片将很快被弃用。请使用docker美元
官方图片： https://hub.docker.com/_/redis /

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