Spring boot and AWS Secret Manager - how to feature flaged the listener to set the secrets only on prod but not on test env - spring-boot

Question

I need to integrate my spring boot app with the AWS Secret manager to retrieve the DB credentials from it. It has to work only on prod environment.
This is what I did until now
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk-secretsmanager</artifactId>
<version>1.12.131</version>
</dependency>
...
SpringApplication application = new SpringApplication(MyApplication.class);
application.addListeners(new DatabasePropertiesListener());
application.run(args);
And my listener implements the
ApplicationListener<ApplicationPreparedEvent>
Is there any way to run my method inside that listener only on specific environment ( kind of feature flag) ? I need to say that this is to early to use variables from properties files.

Answer 1

Update:
When we have to decide before context creation (.i.e. ApplicationListener is no Component/Bean), then we (just mimic profiles) set:
# env: SET MY_FLAG=foo -> System.getenv("MY_FLAG")
# system: java -jar -Dmy.flag=foo myApp.jar -> System.getProperty("my.flag")
# cmd arg:
java -jar myApp.jar aws
..and issue it in our (spring boot) main method like:
if("aws".equalsIgnoreCase(args[0])) // alternatively: System.get...
application.addListeners(new DatabasePropertiesListener());
Misunderstood answer
Sure we can: With spring (boot) core features!
Assuming our ApplicationListener is a "spring managed bean", we annotate it with:
#Component
#Profile("aws") // custom profile (name)
class MyApplicationListener implements ...
{ ... }
...this will not load this "bean" into our context, unless we define:
spring.profiles.acitve=aws,... # a comma separated list of profiles to activate
Profiles
Spring Profiles provide a way to segregate parts of your application configuration and make it be available only in certain environments. Any #Component (Or #Bean,#Service,#Repository...descendants), #Configuration or #ConfigurationProperties can be marked with #Profile to limit when it is loaded, as shown in the ...
... above example.
An advanced application of #Profile annotation:
with multiple profiles: "or"/"and" semantics
"not" (!) operator
#Profile("!local","aws") // (String[]: OR semantics) the annotated component/configuration/property will
// be loaded, when active profiles NOT contains "local" OR contains "aws"
// for AND semantics, we'd use (1 string): "!local & aws"
Activating Profile(s!)
spring.profiles.acitve can be set/added (like any spring property source) through several (14^^, precisely priorized) locations.
E.g. setting environment variable (5th lowest priority, but higher than application.properties (3rd lowest)):
SPRING_PROFILES_ACTIVE=aws
Or as a command line flag (when starting the application, 11th lowest/3rd highest priority):
java -jar myApp.jar --spring.profiles.active=aws,...
#comma separated list
For (spring) tests additionally exists an #ActiveProfiles annotation.
Remarks/Note
Deciding for profiles, we should ensure to "make it consistently" (not raising Nullpointer/BeaninitalizationExceptions ... with dependencies!;). If needed: Creating replacement/local/test (#Profile("!aws")) beans.
Activating a profile "xyz", automatically tries to load application-xyz.properties (with higher priority than application.properties (prio 3.1 - 3.4))...also in (spring-)cloud-config.
Not to forget: The default profile (activated by spring automatically, only when no explicit profile is activated).
Reference
For detailed documentation, please refer to:
Spring Boot - Externalized Configuration
Spring Boot - Profiles
Spring Environment Abstraction chapter
#Profile Javadoc
#ActiveProfiles Javadoc
Profile sample from Configuration Javadoc:
#Configuration classes may be marked with the #Profile annotation to indicate they should be processed only if a given profile or profiles are active:
#Profile("development")
#Configuration
public class EmbeddedDatabaseConfig {
#Bean
public DataSource dataSource() {
// instantiate, configure and return embedded DataSource
}
}
#Profile("production")
#Configuration
public class ProductionDatabaseConfig {
#Bean
public DataSource dataSource() {
// instantiate, configure and return production DataSource
}
}
Alternatively, you may also declare profile conditions at the #Bean method level — for example, for alternative bean variants within the same configuration class:
#Configuration
public class ProfileDatabaseConfig {
#Bean("dataSource")
#Profile("development")
public DataSource embeddedDatabase() { ... }
#Bean("dataSource")
#Profile("production")
public DataSource productionDatabase() { ... }
}
See the #Profile and Environment javadocs for further details.