Having spring bean properties refreshed automatically from properties file - spring

I'm using Spring 2.5.6. I have a bean whose properties are being assign from a property file via a PropertyPlaceholderConfigurer. I'm wondering whether its possible to have the property of the bean updated when the property file is modified. There would be for example some periodic process which checks the last modified date of the property file, and if it has changed, reload the bean.
I'm wondering if there is already something that satisfies my requirements. If not, what would be the best approach to solving this problem?
Thanks for your help.

Might also look into useing Spring's PropertyOverrideConfigurer. Could re-read the properties and re-apply it in some polling/schedular bean.
It does depend on how the actual configured beans use these properties. They might, for example, indirectly cache them somewhere themself.

If you want dynamic properties at runtime, perhaps another way to do it is JMX.

One way to do this is to embed a groovy console in your application. Here's some instructions. They were very simple to do, btw - took me very little time even though I'm not that familiar with groovy.
Once you do that you can simply go into the console and change values inside the live application on the fly.

You might try to use a custom scope for the bean that recreates beans on changes of the properties file. See my more extensive answer here.

Spring Cloud Config has facilities to change configuration properties at runtime via the Spring Cloud Bus and using a Cloud Config Server. The configuration or .properties or .yml files are "externalized" from the Spring app and instead retrieved from a Spring Cloud Config Server that the app connects to on startup. That Cloud Config Server retrieves the appropriate configuration .properties or .yml files from a GIT repo (there are other storage solutions, but GIT is the most common). You can then change configuration at runtime by changing the contents of the GIT repo's configuration files--The Cloud Config Server broadcasts the changes to any Client Spring applications via the Spring Cloud Bus, and those applications' configuration is updated without needing a restart of the app. You can find a working simple example here: https://github.com/ldojo/spring-cloud-config-examples

Related

Any way to split Spring Boot configuration into multiple properties files without having to specify an environment variable/system property

New to Spring Boot here, long-time Spring Framework user though.
I'm looking for a way to split my externalised configuration into multiple .properties files, for better readability and manageability.
I already saw this SO answer: having the ability to specify a list of configuration file names in spring.config.name (which, by the way, doesn't seem to be mentioned in Boot reference documentation, correct me if I'm wrong) would solve my problem perfectly, however that configuration property can be specified only via system properties or environment variables. If I try to specify it inside my application.properties file, it gets ignored. The same happens for spring.config.additional-location. I understand this happens because, when application.properties is read, it's too late to tell Spring Boot to search for different externalised configuration file names. However this is not a proper solution, because the way I split my configuration should be an "implementation detail" that the consumer of my application shouldn't be aware of, so I don't expect the consumer to specify an external parameter otherwise my application breaks out-of-the-box.
I think that a way to do this should be provided. Perhaps some import mechanism for .properties files or the ability to specify spring.config.name even in application.properties (some known and reasonable limitations would be acceptable).
The best I could find out is to use #PropertySource, but this is not profile aware: unless you use some ugly nested class hack, or you put spring.profiles.active variable in the resource name (which will break if multiple profiles have been activated), you won't get the benefit you have for application.properties profile-specific files.
I was not able to find an "official way" to do this, apart from some statements from Spring Boot devs that say that they're rather promoting the use of a single (possibly giant...) externalised configuration file. It seems like this position is not so popular, judging from the post reactions on GitHub, and IMHO it really seems to be a basic feature missing. I have been working with multiple properties files in Spring Framework (using XML configuration) for years and I never felt that having an only huge file would have been better.
If I understand it right, in Boot 1.x this was in some way possible using the location attribute of #ConfigurationProperties, which is however missing in Boot 2.x.
Any suggestion?
Have you tried with Spring Profile?
What you can do is create application-file1.properties/yml, application-file2.properties/yml and put it in config location and then add spring.profile.active=<your env profiles>,file1,file2.
It will load the files.
This profile entry can be in bootstrap.yml, or JVM args to application, in Manifest-<env>.yml in case of Pivotal Cloud Foundry. Not sure on AWS and other cloud provider.
Hope this will help.

Quarkus: How to define and read properties file (or application.properties) outside application or at runtime?

In Quarkus, We have properties file inside project itself called application.properties.
Is there any Quarkus way to define external properties file in my use case like i am developing a mail sender and i want to add recipients in future.
Is it possible to give application.properties outside at local and inject it at runtime?
You can add a configuration file in your application working directory under config/application.properties : https://quarkus.io/guides/config#overriding-properties-at-runtime
There is ongoing discussion to have more runtime configuration capabilities here: https://github.com/quarkusio/quarkus/issues/1218
You can achieve this by keeping .properties (or .yaml) in Spring Cloud Config Server.
It's really easy to set it up. It's is well documented in following link (official documentation):
Quarkus - Reading properties from Spring Cloud Config Server
As loïc says, you can follow the convention and create a config/application.properties. You can also use the property quarkus.config.locations to specify additional config locations. It can be defined at runtime like below
java -Dquarkus.config.locations=app-config/config.properties -jar my-app.jar

Spring Cloud Config fails to update properties dynamically

I have a Camel Spring Boot application where I am printing the value of a property which is set using Spring Cloud Config Server (via Git commit id plugin). The issue is that the value of the property in Camel application is not updated once the value is committed to Git. I have to restart the Camel application which fails the purpose of Spring Cloud Config server. Please note that we are using Git file system in our local machine.
The name of the properties file is CamelSpringBootSample-dev.properties.
As soon as I commit, the config server publishes the updated value at the endpoint on refresh:
http://localhost:8888/CamelSpringBootSample/dev
I have also made the Camel application end point available at:
http://localhost:8181/actuator/env
Here the value of the property is not updated on refresh. However, if I restart the Camel application, the value is reflecting.
The source code for all the three projects are uploaded in github.com.
The config server: https://github.com/sreejeshraj/config-server
The Camel client project (which uses the config server to configure itself): https://github.com/sreejeshraj/camel-config-server
Please do not get misled by the repository name camel-config-server. This is the client of config server, but I accidentally named it incorrectly, apologies.
The local git repository where the configuration properties are stored: https://github.com/sreejeshraj/Git-Config
Please note that I have used the annotation #RefreshScope in my Spring bean component class.
Can you please help me with this? Thanks in advance.
You have to set:
management.endpoints.web.exposure.include=refresh
in bootstrap.properties or bootstrap.yml.
and trigger the /actuator/refresh endpoint.
See #RefreshScope and /refresh not working
Note that as said in the comments, Camel does not update its values when a Spring beans is refreshed and there is no plan to implement this feature. (https://issues.apache.org/jira/browse/CAMEL-13892). You probably could find a solution through Spring Cloud Bus.
As #ortomala-lokni already pointed out, you need to refresh your configuration consumers after an update happened.
If you want a centralized solution for this task (for refreshing many components automatically), take a look at Spring Cloud Bus.
This page gives a quite good overview about the subject.
I had a situation where I had both application.properties and bootstrap.properties file in my client. I that case you should specify spring.application.name and spring.cloud.config.server.git.uri inside bootstrap.yml. I didn't refresh properties having spring.application.name inside applicaiton.properties.

Properties change with out a server restart

I have externalized all my application needed property files from webapps in tomcat. Now i can simply change a property file value without a need of rebuilding the war file and deploy it again. However each change to property file is associated with server recyling.
Is there a way how the recycling can be avoided for a property file change.
I am using spring to read the property files for few webapps and java property traditional way for few webapps.
Please suggest how to acheive
You may want to consider spring-cloud-config-server or spring-cloud-consul all of these options supports distributed properties management as well as value changes refresh without a need to recycle app servers.
And you can use #RefreshScope for Spring #Beans that want to be reinitialized when configuration changes, they also provide the following Management endpoints out of the box and many more as explained on the project git page
/refresh for refreshing the #RefreshScope beans
/restart for restarting the Spring context (disabled by default)
This is supported by either option (spring-cloud-config-server or spring-cloud-consul)
You may also give cfg4j a try. It supports reloading configuration from local files as well as remote services (git repository, Consul, etc.).

Spring cloud config server - more than 1 properties file per app

Does anybody knows if it is possible to expose more than 1 property file per application in Spring Cloud config server?
For example I would like to have defined in my git repo properties for the same app, but in different files:
myapp-customer-services.yml
myapp-products-services.yml
and have all those properties defined inside the files, exposed under "myapp".
No that's not possible currently. I'm not sure it really makes much sense to be honest, since you can easily clearly delineate different sets of properties within a YAML file using separate documents.
Yes it is possible to expose more than 1 property file per application in Spring Cloud config server
You can access it in you client by using following properties
first specify profile which you want
example
myapp-customer.yml
myapp-products.yml
spring.profiles.active=customer,products
spring.cloud.config.name=myapp

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