I am trying to build a Spring Cloud Configuration server that retrieves properties from a proprietary property server (not Git) using a RefreshScope annotation on the clients to re-inject changed properties
Since there are lots of properties and processing, I want to be able to do a conditional request, so that if no properties are changed since the supplied date, nothing will be injected.
I implemented the EnvironmentRepository interface and overrode the findOne() method to only retrieve the properties if they have changed, and otherwise return an empty map.
I also tried returning null from findOne() but that causes a NullPointerException to be thrown in the config server.
If I return the environment object, the properties are re-injected correctly, but I am trying to avoid that in the case where there are no changes
Does Spring provide some hook method where the config server can notify the config client to leave its properties as they are, and not to re-inject its properties?
Related
I have spring boot micro-service with database credentials define in the application properties.
spring.datasource.url=<<url>>
spring.datasource.username=<<username>>
spring.datasource.password=<<password>>
We do not use spring data source to create the connection manually. Only Spring create the database connection with JPA.(org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration)
We only provide the application properties, but spring create the connections automatically to use with the database connection pool.
Our requirement to enhance the security without using db properties in clear text. Two possible methods.
Encrypt the database credentials
Use the AWS secret manager. (then get the credential with the application load)
For the option1, jasypt can be used, since we are just providing the properties only and do not want to create the data source manually, how to do to understand by the spring framework is the problem. If better I can get some working sample or methods.
Regarding the option-2,
first we need to define secretName.
use the secertName and get the database credentials from AWS secret manager.
update the application.properties programatically to understand by spring framework. (I need to know this step)
I need to use either option1 and option2. Mentioned the issues with each option.
What you could do is use environment variables for your properties. You can use them like this:
spring.datasource.url=${SECRET_URL}
You could then retrieve these and start your Spring process using a ProcessBuilder. (Or set the variables any other way)
I have found the solution for my problem.
We need to define org.springframework.context.ApplicationListenerin spring.factories file. It should define the required application context listener like below.
org.springframework.context.ApplicationListener=com.sample.PropsLoader
PropsLoader class is like this.
public class PropsLoader implements ApplicationListener<ApplicationEnvironmentPreparedEvent> {
#Override
public void onApplicationEvent(ApplicationEnvironmentPreparedEvent event) {
ConfigurableEnvironment environment = event.getEnvironment();
String appEnv = environment.getProperty("application.env");
//set new properties based on the application environment.
// calling other methods and depends on the enviornment and get the required value set
Properties props = new Properties();
props.put("new_property", "value");
environment.getPropertySources().addFirst(new PropertiesPropertySource("props", props));
}
}
spring.factories file should define under the resources package and META-INF
folder.
This will set the application context with new properties before loading any other beans.
Can I dynamically refresh properties that are used by Spring Boot's auto configuration setup?
For example, I have the following properties set (via cloud config) to auto configure a dataSource:
spring.datasource.username=user1
spring.datasource.password=test
Now if I change the password prop on the config server, and hit the /refresh endpoint, I can see that the updated prop is retrieved but the DataSource is not refreshed.
I know I can manually configure the DataSource beans and make sure they fall under a RefreshScope, but I was hoping to find a way to mark the auto configured properties as "refreshable". I have some use cases where I'd want to refresh props used by Spring Boot for other beans besides DataSources, and setting up some of those beans manually could be a pain.
I think I spoke too soon, at least as far as my DataSource example goes. A new db connection was being created with the updated props.
Which makes sense especially when looking at the docs here
This didn't re-connect some of my spring.cloud.stream.bindings properties I had, but in that case I can probably solve the issue with #RefreshScope.
There's a configuration property to set in case of the Autoconfigured bean is immutable (don't change the properties after initialized)
You can put a list (set) of classes that you need to be refreshed and you don't have control over the source code, you can put them under the property: spring.cloud.refresh.extra-refreshable
e.g.:
spring
cloud
refresh
extra-refreshable:
- org.springframework.mail.javamail.JavaMailSenderImpl
see: https://cloud.spring.io/spring-cloud-static/Greenwich.SR1/single/spring-cloud.html#refresh-scope
I'm trying to figure out why my custom Environment Repository (in an embedded mode Spring Config application i.e. no stand-along Config server) isn't being picked up.
The object is obviously being constructed (I hit a log print statement at this point) but none of the properties I inject into it (from a hashmap for this example) show up in an env actuator dump i.e. custom.prop.* . The findOne(...) isn't being invoked.
Dump at
https://gist.github.com/balamuru/1047db7080a4da6f067dd7cfac86a2c2
resulting from http://localhost:8282/env
Code at https://github.com/balamuru/config-service-embedded
I have develop a new Connector. This connector requires to be configured with two parameters, lets say:
default_trip_timeout_milis
default_trip_threshold
Challenge is, I want read ${myValue_a} and ${myValue_a} from an API, using an HTTP call, not from a file or inline values.
Since this is a connector, I need to make this API call somewhere before connectors are initialized.
FlowVars aren't an option, since they are initialized with the Flows, and this is happening before in the Mule app life Cycle.
My idea is to create an Spring Bean implementing Initialisable, so it will be called before Connectors are init, and here, using any java based libs (Spring RestTemplate?) , call API, get values, and store them somewhere (context? objectStore?) , so the connector can access them.
Make sense? Any other ideas?
Thanks!
mmm you could make a class that will create the properties in the startup and in this class obtain the API properties via http request. Example below:
public class PropertyInit implements InitializingBean,FactoryBean {
private Properties props = new Properties();
#Override
public Object getObject() throws Exception {
return props;
}
#Override
public Class getObjectType() {
return Properties.class;
}
}
Now you should be able to load this property class with:
<context:property-placeholder properties-ref="propertyInit"/>
Hope you like this idea. I used this approach in a previous project.
I want to give you first a strong warning on doing this. If you go down this path then you risk breaking your application in very strange ways because if any other components depend on this component you are having dynamic components on startup, you will break them, and you should think if there are other ways to achieve this behaviour instead of using properties.
That said the way to do this would be to use a proxy pattern, which is a proxy for the component you recreate whenever its properties are changed. So you will need to create a class which extends Circuit Breaker, which encapsulates and instance of Circuit Breaker which is recreated whenever its properties change. These properties must not be used outside of the proxy class as other components may read these properties at startup and then not refresh, you must keep this in mind that anything which might directly or indirectly access these properties cannot do so in their initialisation phase or your application will break.
It's worth taking a look at SpringCloudConfig which allows for you to have a properties server and then all your applications can hot-reload those properties at runtime when they change. Not sure if you can take that path in Mule if SpringCloud is supported yet but it's a nice thing to know exists.
We're building a Spring-based application which will be delivered to end users as a distribution package. Users are responsible for properly configuring whatever needs to be configured (it's mostly about various filesystem locations, folder access permissions, etc). There's a good idea to make the app help users understand what is not configured or which parts of configuration are invalid.
Our current approach is a custom ApplicationContextInitializer which does all the environment validation "manually" and then registers few "low level" beans in the application context explicitly. If something is wrong, initializer throws, exception is caught somewhere in main(), interpreted (converted into plain English) and then displayed.
While this approach works fine, I'm wondering if there are any best practices to minimize hand-written code and use Spring whenever possible.
Here's an illustrative example. The application requires a folder for file uploads. This means:
There should be a configuration file
This file should be accessible by the app
This file should have no syntax errors
This file should explicitly define some specific property (let it be app.uploads.folder)
This property should describe the existing filesystem entity
This entity should be a folder
The app should have read/write access to this folder
Does Spring provide any tools to implement this sort of validation easily?
Spring Boot has a nice feature for context and external configuration validation. If you define a POJO class and declare it as #ConfigurationProperties then Spring will bind the Environment (external properties and System/OS typically) to its properties using a DataBinder. E.g.
#ConfigurationProperties(name="app.uploads")
public class FileUploadProperties {
private File folder;
// getters and setters ommitted
}
will bind to app.uploads.folder and ensure that it is a File. For extra validation you can do it manually in the setter, or you can implement Validator in your FileUploadProperties or you can use JSR-303 annotations on the fields. By default an external property in app.uploads.* that doesn't bind will throw an exception (e.g. a mis-spelled property name, or a conversion/format error).
If you use Spring Boot Autoconfigure #EnableAutoConfigure you don't have to do anything else, but if it's just vanilla Spring (Boot) you need to say #EnableConfigurationProperties in your #Configuration somewhere as well.
A bonus feature: if you also use the Spring Boot Actuator you will also get JMX and HTTP support (in a webapp) for inspecting the bindable and bound properties of #ConfigurationProperties beans. The HTTP endpoint is "/configprops".