Spring Config server add property at runtime - java

I want to add some property at runtime in spring config server and it should be available to all client applications with #Value annotation.
I wont have this property predefine because I am going calculate that value in spring config server and add to environment.
Can you please help me understand what is best way to achieve this.

Spring cloud configuration contains a feature named 'RefreshScope' which allows to refresh properties and beans of a running application.
If you read about spring cloud config, it looks like it can only load properties from a git repository, but that is not true.
You can use RefreshScope to reload properties from a local file without any need to connect to an external git repository or HTTP requests.
Create a file bootstrap.properties with this content:
# false: spring cloud config will not try to connect to a git repository
spring.cloud.config.enabled=false
# let the location point to the file with the reloadable properties
reloadable-properties.location=file:/config/defaults/reloadable.properties
Create a file reloadable.properties at the location you defined above.
You can leave it empty, or add some properties. In this file you can later, at runtime, change or add properties.
Add a dependency to
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
All beans, that are using properties, that may be changed during runtime, should be annotated with #RefreshScope like this:
#Bean
#RefreshScope
Controller controller() {
return new Controller();
}
Create a class
public class ReloadablePropertySourceLocator implements PropertySourceLocator
{
private final String location;
public ReloadablePropertySourceLocator(
#Value("${reloadable-properties.location}") String location) {
this.location = location;
}
/**
* must create a new instance of the property source on every call
*/
#Override
public PropertySource<?> locate(Environment environment) {
try {
return new ResourcePropertySource(location);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
Configure Spring to bootstrap the configuration using that class.
Create (or extend) the META-INF/spring.factories file in your resource folder:
org.springframework.cloud.bootstrap.BootstrapConfiguration=your.package.ReloadablePropertySourceLocator
This bean will read the properties from the reloadable.properties. Spring Cloud Config will reload it from disk, when you refresh the application.
Add runtime, edit reloadable.properties as you like, then refresh the spring context.
You can do that by sending a POST request to the /refresh endpoint, or in Java by using ContextRefresher:
#Autowired
ContextRefresher contextRefresher;
...
contextRefresher.refresh();
This should also work, if you choose to use it in parallel to properties from a remote git repository.

Related

Spring Cloud Config: Call a bean from bootstrap.properties/yml

Is it possible to call a bean from bootstrap.properties?
I'm trying to implement a Cloud Config Client.
The Bean is similar to:
#Bean
public MyObject myObject(String environment) {
return new MyObject(environment);
}
....
public class MyObject {
private String environment;
// getters setters
}
In the bootstrap.properties file I have the following line:
spring.profiles.active= #Here I should get the value from the bean
Is it possible to write something like:
spring.profiles.active= ${myObject.environment}
Thank you very much.
You can, plugging into spring.factories:
org.springframework.cloud.bootstrap.BootstrapConfiguration=\
com.demo.MyBootstrapConfiguration
And then write a normal Spring Java Configuration Object
#Configuration
public class MyBootstrapConfiguration {
// normal spring java config
}
Based on the docs, the bootstrap file:
Out of the box it is responsible for loading configuration properties
from the external sources, and also decrypting properties in the local
external configuration files
and the its content is meant to be referenced in the beans, not the other way round.
If you want to pass the active profile somehow to it, based on the docs you can:
1) Use -D option while starting the app:
java -jar -Dspring.profiles.active=production demo-0.0.1-SNAPSHOT.jar
2) Set SPRING_PROFILES_ACTIVE property on your OS environment.

How to force the import/loading of rest controller programatically

I'm starting a spring boot rest service which may load different packages depending on the distribution. This means sometimes the distribution will contain some jars where certain REST controllers are, sometimes this controllers are not there.
So How I'm able to tell spring-boot where to find the controllers with a configuration files. Now I'm sending this info by annotations forcing me to create a "main" per distribution. I will like to define a unique main that imports the controllers defined in a file. In other words I want to access the #Importannotation manually as is shown in the sniped bellow:
#Configuration
#PropertySource("conf.cfg")
#Import(value = {RestContorller1.class, RestContorller2.class})
#EnableAutoConfiguration
#ConfigurationProperties
#SpringBootApplication
#RestController
#EnableSwagger2
public class Application {
public static void main(String[] args) {
String confFile = Const.DEFAULT_CONFIGURATION_FILE;
if(args.length>0)
confFile= args[0];
System.setProperty("spring.config.name",confFile);
Boolean hasStarted = DataProcessingCore.start(confFile);
if(hasStarted) {
SpringApplication springApp = new SpringApplication(Application.class);
try {
springApp.setDefaultProperties(Utils.createPropertyFiles(confFile));
} catch (IOException e) {
e.printStackTrace();
}
springApp.addInitializers();
springApp.run(args);
}
}
}
If I understand you corretly, your controllers reside in a JAR imported by maven/gradle to your main project/s.
In order to create auto-configuration like spring boot does, that in the same way can be used to import your controllers when the jar is in the classpath, you can tell spring to find your custom configuration on start-up.
I wrote a simple example for that here: Creating your own auto-configuration
In pricipal, you create a spring-boot application (without the spring boot maven plugin!! it is important for the classpath and packaging). and create a file named spring.factories (you can find the actual content in the guide I linked) that tells any spring-boot application that have this jar to load your configuration that may do a #ComponentScan to search for your controllers or set the #Bean manually.
Doing that, you don't have to do #Import and the controllers will be loaded dynamically.

Spring Boot ignores spring.config.name/location properties

I've got quite a simple application.yml file:
spring:
config:
name: android,ios,test,web
I expected to gain an ability to name config files like android.yml and put them into
classpath:/,classpath:/config/,file:./,file:./config/
as the DEFAULT_SEARCH_LOCATIONS constant from the ConfigFileApplicationListener class specifies. I created a file in the same directory with the main config:
android:
clientId: 0
clientSecret: clientSecret
Then I wrote a #Configuration class with one method to get an instance of ClientDetails by the #ConfigurationProperties:
#Configuration
public class TrustedClientInformationConfiguration {
#Bean(name = ANDROID)
#ConfigurationProperties(prefix = ANDROID)
public ClientDetails getAndroidClientDetails() {
return new BaseClientDetails();
}
}
Unfortunately, after autowiring, I got the instance with unfilled fields. What have I missed?
EDIT1: I found and debugged a method where CONFIG_NAME_PROPERTY = "spring.config.name" is used (it's only one usage), the containsProperty condition always returns false:
private Set<String> getSearchNames() {
if (this.environment.containsProperty(CONFIG_NAME_PROPERTY)) {
return asResolvedSet(this.environment.getProperty(CONFIG_NAME_PROPERTY),
null);
}
return asResolvedSet(ConfigFileApplicationListener.this.names, DEFAULT_NAMES);
}
EDIT2: It is a try to create an oauth2 client configuration by moving properties to a separate file for each trusted client. They should be always instantiated despite the active profile.
The spring.config properties should be set on the command-line as they're needed before any config files are loaded.
However it looks like the feature you actually want is profiles. They're a much easier way to organise different configuration for different environments. Files can be named application-android, application-test, etc.
Documentation

Is it possible to set properties for a Spring Boot application from a bean?

I was wondering if there is any way to do this.
I want to hardcode a property (I know might not be the best), let's say I want to run my application always on port XXX or any other configuration without using a .properties.
Is there any way I can do this from the main? or a configuration bean?
Thanks.
Take a look at this for how to configure a port: Spring Boot - how to configure port
Relevant code is this:
#Controller
public class ServletConfig {
#Bean
public EmbeddedServletContainerCustomizer containerCustomizer() {
return (container -> {
container.setPort(8012);
});
}
In general, most properties that can be configured via application.properties can also be configured through a Java bean. But, I would suggest using application.properties if you can. It allows you to change properties, without having to change source code.
EDIT:
Some other code from the posted link you might find useful:
HashMap<String, Object> props = new HashMap<>();
props.put("server.port", 9999);
new SpringApplicationBuilder()
.sources(SampleController.class)
.properties(props)
.run(args);

Spring Boot Externalizing properties not working

I have looked at the below threads and followed things given there. Still my property override is not happening
Spring Boot - Externalized properties
Profile Specific Property Enablement
Spring Boot External Config
I am on Tomcat 8.0.33 and Spring boot starter web and got this in my setenv.sh
export JAVA_OPTS="$JAVA_OPTS -Dlog.level=INFO -Dspring.config.location=file:/opt/jboss/apache-tomcat-8.0.33/overrides/ -Dspring.profiles.active=dev"
And in the overrides folder I got 2 files
1) application.properties
2) application-dev.properties
The application.properties has a single entry in it
spring.profiles.active=dev
I see that the proper log.level is fed to my code which means this command is working. Its just that I am clueless as to why my override is not happening as expected
I don't have any `PropertyPlaceholderConfigurer code in my workspace. I am not even sure if I need 1
I don't use this method to externalise properties. First, I'll try a suggestion for your method and then I'll show you what I'm using.
The suggestion for your method is to use file:/// instead of file:/ as with Spring I found that when not passing the three slashes after the colon it didn't recognise the property.
I've created a sample project for you, available here with instructions.
Now for the method I use.
I define a Configuration file for each profile and I keep the application.properties file under src/main/resources.
Then I use the #Profile and #PropertySource annotations on each configuration file.
For example:
#Configuration
#Profile("dev")
#PropertySource("file:///${user.home}/.devopsbuddy/application-dev.properties")
public class DevelopmentConfig {
#Bean
public EmailService emailService() {
return new MockEmailService();
}
#Bean
public ServletRegistrationBean h2ConsoleServletRegistration() {
ServletRegistrationBean bean = new ServletRegistrationBean(new WebServlet());
bean.addUrlMappings("/console/*");
return bean;
}
}
And
#Configuration
#Profile("prod")
#PropertySource("file:///${user.home}/.devopsbuddy/application-prod.properties")
public class ProductionConfig {
#Bean
public EmailService emailService() {
return new SmtpEmailService();
}
}
I have also got a Configuration file that is valid for all profiles, which I call ApplicationConfig, as follows:
#Configuration
#EnableJpaRepositories(basePackages = "com.devopsbuddy.backend.persistence.repositories")
#EntityScan(basePackages = "com.devopsbuddy.backend.persistence.domain.backend")
#EnableTransactionManagement
#PropertySource("file:///${user.home}/.devopsbuddy/application-common.properties")
public class ApplicationConfig {
}
My src/main/resources/application.properties file looks like the following:
spring.profiles.active=dev
default.to.address=me#example.com
token.expiration.length.minutes=120
Of course I could externalise the spring.profile.active property by passing it as a system property but for my case and for now it's fine.
When running the application, if I pass the "dev" profile, Spring will load all properties and Beans defined in the DevelopmentConfig class plus all those in ApplicationConfig. If I pass "prod", the ProductionConfig and ApplicationConfig properties will be loaded instead.
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