Supposed we had a couple of services service-1,service-2, service-3, we can handle global configurations like DB configs,environment configs etc using an externalized service like spring cloud config server or consul. But what is the best way to handle admin related settings in Micro-services e.g Max funding amount, vat, transaction limit etc setting that don't need a programmer to change ? note multiple services can use these values.
one way of doing this would be creating a bean which loads the data at the start of the app from db. In db you can have a table with admin privileges provide simple insert/update queries to the user who can/wants execute them. This user can be admin of the app who is using your app.
Other way would be creating your own properties/attributes and providing them in application.properties file. You can load those properties any of the beans which you think will need them.
eg (for spring boot):-
spring.max.transaction.limit -- in application.poperties
#Value("${spring.max.transaction.limit}")
private String transactionLimit; -- in the bean
Related
I am implementing a Spring Boot application which will be providing a multitenant environment. That is achieved in my case by using a database schema for each customer. Example see this project.
Now I am wondering how to implement tenant-specific configurations. I am using #ConfigurationProperties to bundle my property values, but these are getting instantiated once and not for each tenant.
What if I would like to use Spring Cloud Config with multiple tenant specific git repository as an configuration backend. Would it be possible when using a jdbc backend for Spring Cloud Config?
Is there any way with default Spring mechanisms or do I have to implement a database based configuration framework myself?
Edit: For example I have two tenants called Tenant1 and Tenant2. Both are running over the same application in the same context and are writing in the database schemes tenant_1 and tenant_2.
Identification of tenants is happening over keycloak (see Spring Keycloak multi tenant example). So I identify the tenantId from the jwt token and select the database connection like described here.
But now I would need the same mechanism for #Configuration beans. Since #Configuration beans are as far as I know Singletons, so there is always ONE configuration per application scope, and not ONE configuration per tenant.
So using Spring Cloud Config Tenant1 is using https://git-url/tenant1, Tenant2 is using Hashicorp Vault as backend and perhaps Tenant3 will be using a jdbc based configuration backend. And all of that in ONE (of course scalable) application.
In case your application uses tenant specific files (html templates etc), the following can be applied. As I have used the below approach for handling many tenants and works fine and easy to maintain.
I would suggest that you maintain a consistent configuration source (JDBC) for all of your tenant configurations. This helps you have a single source that is cacheable and scalable for your application. Also, you could have your tenants navigate to a configuration page to manage their settings and alter them to suit their needs at any point of time on the fly. (Example Settings: Records Per Page, Theme, Logo, Filters etc...)
Having the tenant configuration in files in git will be a difficult task when you wanted to auto-provision tenant's when they sign-up as it will involve couple of distributed services. Having them in a TenantSettings table with the tenantId as a column could help you get the data in no time and will be easy.
You can use Spring Cloud Config for your scenario and it is adoptable. It is easily configurable and provides out of the box features. For your specific scenario, you can have any number of microservices running yet all controlled by one Spring Cloud Config Server which is connected to one Git Repository. Your all microservices are asking configuration properties from Spring Cloud Config Server and it is directly fetching properties from Git Repository. That repository can have multiple property files. It can hold common properties for all the microservices or specific service based configuration properties. If you want to keep confidential properties more securely, that is also made possible via HashiCorp vault. I will leave an image below for you to get a better idea about this concept.
In the below image, you can see the Git Repository with common configuration property files and specific configuration property files for different services yet in same repository.
I will add another image for you to get a better idea how does this can be arranged with application profiles as well.
Finally I will add something additional to show the power of Spring Cloud Config and out of the box features it allows us to play with. You can automatically refresh configuration properties in running application as well. You can configure Spring Cloud Config to do that. I will add an architectural diagram to achieve that.
References for this answer is taken from Spring in Action, Fifth Edition
Craig Walls
How would one go about managing the data in their PostgreSQL database on their JHipster generated server? My goal is to be able to periodically check the items in the database and perform certain tasks based on the database contents.
I'm new to using JHipster and I'm not sure how I'd go about adding or removing entities as well as adding items to entities on the server. I understand that services facilitate doing these operations for the client-side, but I can't see how I would use the same approach to do what I need on the server (if this is even the correct approach).
To schedule a task on backend you can annotate a public method of a service with #Scheduled, you can find an example in the code generated by JHipster in UserService class look at the removeNotActivatedUsers() method.
I am trying to develop a microservice by using sprin and spring boot with postgresql database. I am here using distributted datbase. So for particular region I am using one DB, and for other region I am using different DB. Currently I only tried with one database. I added datasource name , username and password in application.properties.
Here my doubt is that, if I am using multiple distributed database, how cam mention different DB source URL in configuration (application.properties)? I am using following structure to use one database currently,
spring.datasource.url=jdbc:postgresql://localhost/milleTech_users
spring.datasource.username=postgres
spring.datasource.password=postgresql
spring.jpa.generate-ddl=true
Like above.
So if I am using multiple DB for multiple region How I can give configuration conditionally here? I am new to microservice world and distributed database design pattern.
Multiple Database details cannot be managed within a single application.properties.
Consider using Spring Cloud Config where in you can create multiple application.properties with different profile names for every application.
In your case, the profile names could reflect the region. When you deploy to a particular region, launch the app with that profile name so that the required config would be loaded and appropriate database connection would be used
Edit :
Also in your case, if you can set environment variables, you can explore on the following option mentioned in this thread
I have a REST web service exposed at http://server:8080/my-production-ws by JBoss (7). My spring (3.2) configuration has a datasource which points to a my-production-db database. So far so good.
I want to test that web service from the client side, including PUT/POST operations but I obviously don't want my tests to affect the production database.
Is there an easy way to have spring auto-magically create another web service entry point at http://server:8080/my-test-ws or maybe http://server:8080/my-production-ws/test that will have the exact same semantics as the production web service but will use a my-test-db database as a data source instead of my-production-db?
If this is not possible, what is the standard approach to integration testing in that situation?
I'd rather not duplicate every single method in my controllers.
Check the spring Profiles functionality, this should solve the problem. With it its possible to create two datasources with the same bean name in different profiles and then activate only one depending on a parameter passed to the the JVM.
I have a project that has the following requeriments:
Allow users to login in the same Web Application using different schemas following a criteria;
Dynamically route the datasource against a rule - for example, users in Company A should access schema A, users in Company B should access schema B;
The business logic which authenticates the user`s should be in a business component - EJB, because new applications can be added and this logic must be outside the Web Application.
I read about using Dynamic Data Source Routing. The CustomerContextHolder has a field which is ThreadLocal. Is ThreadLocal a guarantee that the user A will access the schema A following my criteria? Will the code be thread safe?
The way i understand is that you need multi tenency for spring along with datasource.
Probably you have have a look to spring extension which might help
https://github.com/mariofts/spring-multitenancy