动态操作应用程序属性 - 保管库设置(或任何其他值)

Question

我希望能够在我的应用程序正在使用的第三方组件之间灵活选择。自动取款机 我有硬编码值

spring.cloud.vault.token=ffffffff-ffff-ffff-ffff-ffffffffffff
spring.cloud.vault.scheme=http
spring.cloud.vault.application-name=test
spring.cloud.vault.host=127.0.0.1
spring.cloud.vault.port=8200

目标是：

• 如果设置了spring.cloud.vault.host请尝试使用它。如果spring.cloud.vault.host为空，请使用 改为本地数据库(使用正确的配置(

我的第一个想法是使用environment变量，例如：

spring.cloud.vault.token=${VAULT_TOKEN}
spring.cloud.vault.scheme=${VAULT_SCHEME}
spring.cloud.vault.application-name=${VAULT_APP_NAME}
spring.cloud.vault.host=${VAULT_HOST}
spring.cloud.vault.port=${VAULT_PORT}

并在以后使用组件类，如下所示：

@Component
public class VaultHelper {
private final VaultOperations vaultOperations;
@Value("${spring.cloud.vault.host}")
String vaultHostname;
@Autowired
public VaultHelper(VaultOperations vaultOperations){
this.vaultOperations = vaultOperations;
}

public void saveToVault(String password){
if (!vaultHostname.equals("")) { 
// Use vaultOperations to store password
} else {
// Use plaintext db storage
}
}

public byte[] readFromVault(String passwordLoc){
if (!vaultHostname.equals("")) {
// Use vaultOperations to access password
} else {
// return plaintext password
}
return new byte[0];
}

}

这样，我可以从环境变量(从 docker-compose 运行应用程序(设置${VAULT_HOST}，或者只是在本地机器上将--spring.cloud.vault.host=URL设置为java参数。

不幸的是，我在解解析字段时遇到异常${VAULT_PORT}

Caused by: org.springframework.core.convert.ConversionFailedException: Failed to convert from type [java.lang.String] to type [int] for value '${VAULT_PORT}'; nested exception is java.lang.NumberFormatException: For input string: "${VAULT_PORT}"
at org.springframework.core.convert.support.ConversionUtils.invokeConverter(ConversionUtils.java:47) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:191) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
at org.springframework.boot.context.properties.bind.BindConverter$CompositeConversionService.convert(BindConverter.java:170) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:96) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:88) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.context.properties.bind.Binder.bindProperty(Binder.java:435) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:380) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:320) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
... 83 common frames omitted
Caused by: java.lang.NumberFormatException: For input string: "${VAULT_PORT}"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) ~[na:1.8.0_231]
at java.lang.Integer.parseInt(Integer.java:569) ~[na:1.8.0_231]
at java.lang.Integer.valueOf(Integer.java:766) ~[na:1.8.0_231]
at org.springframework.util.NumberUtils.parseNumber(NumberUtils.java:211) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
at org.springframework.core.convert.support.StringToNumberConverterFactory$StringToNumber.convert(StringToNumberConverterFactory.java:62) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
at org.springframework.core.convert.support.StringToNumberConverterFactory$StringToNumber.convert(StringToNumberConverterFactory.java:49) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
at org.springframework.core.convert.support.GenericConversionService$ConverterFactoryAdapter.convert(GenericConversionService.java:436) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
at org.springframework.core.convert.support.ConversionUtils.invokeConverter(ConversionUtils.java:41) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
... 90 common frames omitted

Process finished with exit code 1

谁能给我一个提示如何让它工作？

Answer 1

我想这是事实，您没有提供默认/回退。在这种情况下，当它找不到相应的环境变量时，它只是将字段 PORT 声明为给定的字符串。尝试使用 (:).

您还可以提供另一个变量作为默认值，您知道该变量将被设置。

spring.cloud.vault.port=${VAULT_PORT}:9000

spring.cloud.vault.port=${VAULT_PORT:8200}