我如何将我的Spring Boot应用连接到同一Kubernetes命名空间内的Redis服务器？

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英文:

How can I connect my springboot application to my redis server within the same kubernetes namespace?

问题

我的Kubernetes命名空间同时托管了我的Spring Boot应用程序和Redis服务。然而，当我运行Spring Boot应用程序时，我收到了以下错误：

  1. org.springframework.data.redis.RedisConnectionFailureException: Cannot get Jedis connection; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
  2. ...
  3. Caused by: redis.clients.jedis.exceptions.JedisConnectionException: Failed connecting to localhost:6379

我将发布应用程序和Redis服务器的清单YAML如下：

以下是成功部署我的应用程序到命名空间并可以从URL访问的清单：

这个清单成功地将我的应用程序部署到了命名空间，并且我可以从URL访问它。

以下是我的Spring Boot应用程序的配置文件：

  1. import org.springframework.cache.annotation.EnableCaching;
  2. import org.springframework.context.annotation.Bean;
  3. import org.springframework.context.annotation.Configuration;
  4. import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
  5. import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
  6. import org.springframework.data.redis.core.RedisTemplate;
  7. import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
  8. import org.springframework.data.redis.serializer.StringRedisSerializer;
  10. @Configuration
  11. @EnableCaching
  12. public class CacheConfig {
  14.     @Bean
  15.     public JedisConnectionFactory redisConnectionFactory() {
  16.         return new JedisConnectionFactory(new RedisStandaloneConfiguration("127.0.0.1", 6379));
  17.     }
  19.     @Bean
  20.     public RedisTemplate<String, Object> redisTemplate(JedisConnectionFactory jedisConnectionFactory) {
  21.         RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
  22.         redisTemplate.setDefaultSerializer(new GenericJackson2JsonRedisSerializer());
  23.         redisTemplate.setKeySerializer(new StringRedisSerializer());
  24.         redisTemplate.setHashKeySerializer(new GenericJackson2JsonRedisSerializer());
  25.         redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
  26.         redisTemplate.setConnectionFactory(jedisConnectionFactory);
  27.         return redisTemplate;
  28.     }
  30. }

我的Redis服务器是否正确部署？我是否需要以某种方式将Spring Boot应用程序绑定到我的Redis服务器？

您的Redis服务器似乎已正确部署到命名空间中。但是，根据错误消息和您的Spring Boot应用程序配置来看，应用程序正在尝试连接到本地主机（localhost）的6379端口，而这似乎不适用于Kubernetes环境。

在Kubernetes中，容器之间通常无法直接访问本地主机。您应该使用服务名称来引用Redis服务，而不是直接使用本地主机。

在您的Spring Boot应用程序的配置文件中，将以下行：

  1. return new JedisConnectionFactory(new RedisStandaloneConfiguration("127.0.0.1", 6379));

更改为引用Redis服务的名称，如下所示：

  1. return new JedisConnectionFactory(new RedisStandaloneConfiguration("redis-service", 6379));

这将允许您的Spring Boot应用程序在Kubernetes中正确连接到Redis服务。确保在应用程序部署清单中也正确设置了环境变量或配置，以指向Redis服务的名称。

英文:

I have a kubernetes namespace that hosts both my springboot application and the redis service. However when I run the springboot app I get error

  1. org.springframework.data.redis.RedisConnectionFailureException: Cannot get Jedis connection; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
  2. ...
  3. Caused by: redis.clients.jedis.exceptions.JedisConnectionException: Failed connecting to localhost:6379

Ill post both the manifest yaml for the application and redis server below.

  1. apiVersion: apps/v1
  2. kind: Deployment
  3. metadata:
  4.   name: spring-deployment
  5.   namespace: spring-poc
  6.   labels:
  7.     app: spring
  8. spec:
  9.   replicas: 1
  10.   selector:
  11.     matchLabels:
  12.       app: spring
  13.   template:
  14.     metadata:
  15.       labels:
  16.         app: spring
  17.     spec:
  18.       containers:
  19.         - name: spring
  20.           image: spring-application
  21.           resources:
  22.             requests:
  23.               memory: 1G
  24.               cpu: &quot;500m&quot;
  25.             limits:
  26.               memory: 1G
  27.               cpu: 1
  28.           ports:
  29.             - name: http
  30.               containerPort: 8080
  31.           securityContext:
  32.             runAsUser: 1000
  33.       imagePullSecrets:
  34.         - name: prod.secret
  35. ---
  36. apiVersion: v1
  37. kind: Service
  38. metadata:
  39.   name: spring-service
  40.   namespace: spring-poc
  41.   labels:
  42.     app: spring-service
  43. spec:
  44.   selector:
  45.     app: spring
  46.   type: ClusterIP
  47.   ports:
  48.     - name: http
  49.       port: 8080
  50.       targetPort: 8080
  51. ---
  52. apiVersion: networking.k8s.io/v1
  53. kind: Ingress
  54. metadata:
  55.   name: spring-ingress
  56.   namespace: spring-poc
  57. spec:
  58.   rules:
  59.     - host: spring.url.com
  60.       http:
  61.         paths:
  62.           - path: /
  63.             pathType: Prefix
  64.             backend:
  65.               service:
  66.                 name: spring-service
  67.                 port:
  68.                   number: 8080
  69.   tls:
  70.     - hosts:
  71.         - spring.url.com

This manifest successfully deploys my app to the namespace and I can access it from the url.

  1. apiVersion: apps/v1
  2. kind: Deployment
  3. metadata:
  4.   name: redis-deployment
  5.   namespace: spring-poc
  6.   labels:
  7.     app: redis
  8. spec:
  9.   replicas: 1
  10.   selector:
  11.     matchLabels:
  12.       app: redis
  13.   template:
  14.     metadata:
  15.       labels:
  16.         app: redis
  17.     spec:
  18.       containers:
  19.         - name: redis
  20.           image: redis
  21.           resources:
  22.             requests:
  23.               memory: 1G
  24.               cpu: &quot;500m&quot;
  25.             limits:
  26.               memory: 1G
  27.               cpu: 1
  28.           ports:
  29.             - name: redis
  30.               containerPort: 6379
  31.           securityContext:
  32.             runAsUser: 1000
  33.       imagePullSecrets:
  34.         - name: prod.secret
  35. ---
  36. apiVersion: v1
  37. kind: Service
  38. metadata:
  39.   name: redis-service
  40.   namespace: spring-poc
  41.   labels:
  42.     app: redis
  43. spec:
  44.   selector:
  45.     app: redis
  46.   type: ClusterIP
  47.   ports:
  48.     - name: redis
  49.       port: 6379
  50.       targetPort: 6379

This manifest successfully deploys a redis server to my namespace. If I kubectl exec -it redis-deployment -- redis-cli and run ping it returns pong.

Below is my configuration file for the springboot application

  1. import org.springframework.cache.annotation.EnableCaching;
  2. import org.springframework.context.annotation.Bean;
  3. import org.springframework.context.annotation.Configuration;
  4. import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
  5. import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
  6. import org.springframework.data.redis.core.RedisTemplate;
  7. import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
  8. import org.springframework.data.redis.serializer.StringRedisSerializer;
  10. /**
  11.  * The type Cache config.
  12.  */
  13. @Configuration
  14. @EnableCaching
  15. public class CacheConfig {
  17.     /**
  18.      * Redis connection factory jedis connection factory.
  19.      *
  20.      * @return the jedis connection factory
  21.      */
  22.     @Bean
  23.     public JedisConnectionFactory redisConnectionFactory() {
  24.         return new JedisConnectionFactory(new RedisStandaloneConfiguration(&quot;127.0.0.1&quot;, 6379));
  25.     }
  27.     /**
  28.      * Redis template.
  29.      *
  30.      * @param jedisConnectionFactory the jedis connection factory
  31.      * @return the redis template
  32.      */
  33.     @Bean
  34.     public RedisTemplate&lt;String, Object&gt; redisTemplate(JedisConnectionFactory jedisConnectionFactory) {
  35.         RedisTemplate&lt;String, Object&gt; redisTemplate = new RedisTemplate&lt;&gt;();
  36.         redisTemplate.setDefaultSerializer(new GenericJackson2JsonRedisSerializer());
  37.         redisTemplate.setKeySerializer(new StringRedisSerializer());
  38.         redisTemplate.setHashKeySerializer(new GenericJackson2JsonRedisSerializer());
  39.         redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
  40.         redisTemplate.setConnectionFactory(jedisConnectionFactory);
  41.         return redisTemplate;
  42.     }
  44. }

Is my redis server deployed correctly? Do I need to bind the springboot application to my redis server somehow?

答案1

得分: 1

你正在创建一个使用本地主机（127.0.0.1）的 RedisStandaloneConfiguration。Pods（Redis 和你的 Spring 应用程序）是分开的，无法以这种方式通信。

因此，你需要将 127.0.0.1 替换为 redis-service.spring-poc，如下所示：

  1. [...]
  2. @Bean
  3. public JedisConnectionFactory redisConnectionFactory() {
  4.     return new JedisConnectionFactory(new RedisStandaloneConfiguration("redis-service.spring-poc", 6379));
  5. }
  6. [...]

最佳实践是从环境变量或应用程序配置中获取这些信息，这样你仍然可以在工作站上使用 localhost 进行测试。

解释：

Kubernetes 提供了开箱即用的 DNS。你可以使用 <service-name>.<namespace-name> 查询每个 Pod。你可以将其类比为类似于 google.de 的域名。因此，你可以通过这种方式连接到每个 Pod。在你的示例中，Redis 服务被称为 redis-service，它需要与部署在同一命名空间中，即 spring-poc（尽管你的清单中写着 namespace: 48713-poc，但这不会起作用）。因此，要从 Spring 连接到 Redis，你需要连接到 redis-service.spring-poc:6379。

从技术上讲，redis-service:6379 也可以工作，但我建议更加详细。还可以查看有关 Pod 之间通信的 DNS 文档。

英文:

You're creating a RedisStandaloneConfiguration with localhost (127.0.0.1). The pods (redis and your spring app) are separated and can't communicate like that.

So you need to replace 127.0.0.1 with redis-service.spring-poc, like this:

  1. [...]
  2. @Bean
  3.     public JedisConnectionFactory redisConnectionFactory() {
  4.         return new JedisConnectionFactory(new RedisStandaloneConfiguration(&quot;redis-service.spring-poc&quot;, 6379));
  5.     }
  6. [...]

Best practice would be to get that from environment variables or application config, so you can still use localhost for testing on your workstation.

Explanation:

Kubernetes provides out-of-the-box dns. You can query every pod with &lt;service-name&gt;.&lt;namespace-name&gt;. You can think of it similar to a domain like google.de. So you can connect to every pod via it's service by that. In your example the redis service is called redis-service and it needs to be in the same namespace as the deployment, which is spring-poc (though your manifest says namespace: 48713-poc which wouldn't work). So to connect from spring to redis you need to connect to redis-service.spring-poc:6379.

Technically redis-service:6379 would also work, but I'd recommend to be verbose. Also check out the docs about dns for pod to pod communication.

huangapple
  • 本文由 发表于 2023年6月15日 04:56:56
  • 转载请务必保留本文链接：https://go.coder-hub.com/76477482.html
  • kubernetes
  • redis
  • spring-boot
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