I am deploying an springboot application in a local kubernetes cluster. I use Hashicorp Vault to store some secrets ( a username and a pasword), hoping to retrieve the secrets in springboot application. I followed the Hashicorp tutorial to configure the Vault and deployment.yaml files. A vault is configured to authenticate via a Kubernetes service account, as described in the tutorial. related Hashicorp tutorial

When creating the pod for springboot application, The the application container and the Vault sidecar agent is successfully creating, but the application terminates immediately as it cannot create the bean associated with vault configuration. How to resolve this issue?

Following given is my springboot bootstrap.properties file.

spring.cloud.vault.uri=http://localhost:8200
spring.cloud.vault.generic.backend=internal
spring.cloud.vault.generic.default-context =database/config

Following given is the VaultConfiguration class.

@Configuration
public class vaultConfiguration {

    @Value("${username}")
    private String username;

    @Value("${password}")
    private String password;

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
   }
     }

Below given is the application error log.

2021-12-17 03:09:12.108  INFO 1 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1808 ms
2021-12-17 03:09:12.474  WARN 1 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vaultConfiguration': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'username' in value "${username}"
2021-12-17 03:09:12.478  INFO 1 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2021-12-17 03:09:12.502  INFO 1 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-12-17 03:09:12.537 ERROR 1 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vaultConfiguration': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'username' in value "${username}"
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:405) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1431) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.13.jar!/:5.3.13]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.13.jar!/:5.3.13]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.1.jar!/:2.6.1]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:730) [spring-boot-2.6.1.jar!/:2.6.1]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) [spring-boot-2.6.1.jar!/:2.6.1]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) [spring-boot-2.6.1.jar!/:2.6.1]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) [spring-boot-2.6.1.jar!/:2.6.1]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290) [spring-boot-2.6.1.jar!/:2.6.1]
	at com.persistent.vaulttest.VaultTestApplication.main(VaultTestApplication.java:16) [classes!/:0.0.1-SNAPSHOT]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_212]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_212]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_212]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_212]
	at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49) [app.jar:0.0.1-SNAPSHOT]
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:108) [app.jar:0.0.1-SNAPSHOT]
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:58) [app.jar:0.0.1-SNAPSHOT]
	at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88) [app.jar:0.0.1-SNAPSHOT]
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'username' in value "${username}"
	at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:180) ~[spring-core-5.3.13.jar!/:5.3.13]
	at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:126) ~[spring-core-5.3.13.jar!/:5.3.13]
	at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:239) ~[spring-core-5.3.13.jar!/:5.3.13]
	at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:210) ~[spring-core-5.3.13.jar!/:5.3.13]
	at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:175) ~[spring-context-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:936) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1321) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:656) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:639) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.13.jar!/:5.3.13]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.13.jar!/:5.3.13]
	... 25 common frames omitted

Thank you.