I have question about placeholder resolution priority when using consul-config and vault-config
I created simple app using this information
My dependencies are:
dependencies {
compile('org.springframework.cloud:spring-cloud-starter-consul-config')
compile('org.springframework.cloud:spring-cloud-starter-vault-config')
compile('org.springframework.boot:spring-boot-starter-webflux')
compile('org.springframework.cloud:spring-cloud-starter')
testCompile('org.springframework.boot:spring-boot-starter-test')
}
Note that I'm not using service discovery.
Doing next step I created property foo.prop = consul (in consul storage)
and foo.prop = vault.
When using:
@Value("${foo.prop}")
private String prop;
I'm getting vault as an output, but when I delete foo.prop from vault and restart app, I will get consul.
I did this few times in different combinations and seems vault config has higher priority over consul.
My question is where I can find information about resolving strategy.(Imagine that we added as third zookeeper-config). Seems spring-core documentation keep quiet about this.
From what I understood by debugging the Spring source code... Now Vault has a priority.
My investigation results: PropertySourceBootstrapConfiguration.java is responsible to initialize all property sources in bootstrap phase. Before locating properties it sorts all propertySourceLocators by Order:
AnnotationAwareOrderComparator.sort(this.propertySourceLocators);
Vault always "wins" because instance of LeasingVaultPropertySourceLocator (at least this one was created during my debugging) implements PriorityOrdered interface. Instance of ConsulPropertySourceLocator has @Order(0) annotation. According to OrderComparator : instance of PriorityOrdered is 'more important'.
In case you have another PriorityOrdered property source (e.g. custom one) you can influence this order by setting spring.cloud.vault.config.order for Vault.
For now without customization I don't know how to change priority between Vault and Consul.