why do we need spring cloud config server

by Prof. Art Little Published 2 years ago Updated 2 years ago

Spring Cloud Config provides server and client-side support for externalized configuration in a distributed system. With the Config Server you have a central place to manage external properties for applications across all environments.

What is Spring Cloud-config?

Spring cloud config is providing support of externalized configuration for server side and client-side system which was distributed. This is a guide to Spring Cloud Config. Here we discuss the definition, What is spring cloud-config, Spring cloud config Server respectively.

What is config server in Spring Boot?

Spring Cloud Config Server provides an HTTP resource-based API for external configuration (name-value pairs or equivalent YAML content). The server is embeddable in a Spring Boot application, by using the @EnableConfigServer annotation. Consequently, the following application is a config server: ConfigServer.java.

Can a configuration system force an application to use configuration data?

A configuration system cannot force an application to use configuration data in any particular way. Consequently, overrides are not enforceable. However, they do provide useful default behavior for Spring Cloud Config clients. Tip

How does Spring Cloud config server clone the remote repository?

As Spring Cloud Config Server has a clone of the remote git repository after check-outing branch to local repo (e.g fetching properties by label) it will keep this branch forever or till the next server restart (which creates new local repo).

Why do we need a config server?

Config Server is an externalized application configuration service. It is based on the open-source Spring Cloud Config project, which provides a centralized server for delivering external configuration properties to an application and a central source for managing this configuration across deployment environments.

What is the use of config server in Microservices?

Central configuration server provides configurations (properties) to each micro service connected. As mentioned in the above diagram, Spring Cloud Config Server can be used as a central cloud config server by integrating to several environments.

What are the features of spring cloud config server?

"Spring cloud config server" provides client-side support for externalized configuration in a distributed system. With the distributed configurations, we have a central place to manage external properties for applications across all environment.

Why do we need spring cloud dependency?

It provides us to monitor our every service, by providing one common UI. It helps developers to keep track of their services. easy to use, handle, and implements as well.

How does Spring cloud Config server work?

Spring Cloud Config is Spring's client/server approach for storing and serving distributed configurations across multiple applications and environments. This configuration store is ideally versioned under Git version control and can be modified at application runtime.

How does config server work?

Configuration Server runs on the Tomcat port 8888 and application configuration properties are loaded from native search locations. Now, in file:///C:/configprop/, place your client application - application. properties file. For example, your client application name is config-client, then rename your application.

What is the importance of SpringBootApplication?

Spring Boot @SpringBootApplication annotation is used to mark a configuration class that declares one or more @Bean methods and also triggers auto-configuration and component scanning. It's same as declaring a class with @Configuration, @EnableAutoConfiguration and @ComponentScan annotations.

What is the use of spring configuration?

Spring @Configuration annotation is part of the spring core framework. Spring Configuration annotation indicates that the class has @Bean definition methods. So Spring container can process the class and generate Spring Beans to be used in the application.

How many types of configuration are there in spring?

The book states that there are 3 ways to configure the Spring Container.

What is Spring Cloud config client?

Spring Cloud Config provides server-side and client-side support for externalized configuration in a distributed system. With the Config Server, you have a central place to manage external properties for applications across all environments.

How do I create a Spring Cloud config server?

Setting up Spring Cloud Config ServerStep 1: Create a Maven project using Spring Initializr https://start.spring.io/Step 2: Choose the Spring Boot version 2.2. ... Step 3: Provide the Group name. ... Step 4: Provide the Artifact id. ... Step 5: Add the Spring Boot DevTools and Config Server dependencies.More items...

What is difference between spring boot and Spring Cloud?

Spring Boot is a Java-based open-source framework for developing services. Its major goal is to cut down on development and testing time. Their apps don't need as much Spring setup as other Spring applications. Spring Cloud is a tool for centralizing form management.

What is the purpose of config?

In computing, configuration files (commonly known simply as config files) are files used to configure the parameters and initial settings for some computer programs. They are used for user applications, server processes and operating system settings.

What is microservices configuration?

Microservice configuration management is defined as the process of tracking changes to microservices and their consuming applications over time. In microservices, you have multiple applications and multiple instances to configure and manage.

What are the 3 components of a microservice?

Components of Microservices. There are the following components of microservices: Spring Cloud Config Server. Netflix Eureka Naming Server.

What is configuration server in spring boot?

What is Spring Cloud Config?from spring.io

Spring Cloud Config provides server and client-side support for externalized configuration in a distributed system. With the Config Server you have a central place to manage external properties for applications across all environments. The concepts on both client and server map identically to the Spring Environment and PropertySource abstractions, so they fit very well with Spring applications, but can be used with any application running in any language. As an application moves through the deployment pipeline from dev to test and into production you can manage the configuration between those environments and be certain that applications have everything they need to run when they migrate. The default implementation of the server storage backend uses git so it easily supports labelled versions of configuration environments, as well as being accessible to a wide range of tooling for managing the content. It is easy to add alternative implementations and plug them in with Spring configuration.

What port does Spring Boot use?from cloud.spring.io

Like all Spring Boot applications, it runs on port 8080 by default, but you can switch it to the more conventional port 8888 in various ways. The easiest, which also sets a default configuration repository, is by launching it with spring.config.name=configserver(there is a configserver.ymlin the Config Server jar). Another is to use your own application.properties, as shown in the following example:

Why do I need to clone a repository?from cloud.spring.io

Setting a repository to be cloned when the Config Server starts up can help to identify a misconfigured configuration source (such as an invalid repository URI) quickly , while the Config Server is starting up . With cloneOnStartnot enabled for a configuration source, the Config Server may start successfully with a misconfigured or invalid configuration source and not detect an error until an application requests configuration from that configuration source.

What is aws-java-sdk-corejar?from cloud.spring.io

The aws-java-sdk-corejar is an optional dependency. If the aws-java-sdk-corejar is not on your classpath, the AWS Code Commit credential provider is not created, regardless of the git server URI.

Where does config.name come from?from spring.io

The value of config.name in the sample (or any other values you bind to in the normal Spring Boot way) can come from local configuration or from the remote Config Server. The Config Server will take precedence by default. To see this look at the /env endpoint in the application and see the configServer property sources.

Does Spring Cloud Config Server have a git repository?from cloud.spring.io

Spring Cloud Config Server supports a git repository URL with placeholders for the {application}and {profile}(and {label}if you need it, but remember that the label is applied as a git label anyway). So you can support a “one repository per application”policy by using a structure similar to the following:

Can you set Spring Cloud to accept empty?from cloud.spring.io

You can set spring.cloud.config.server.accept-empty to false so that Server would return a HTTP 404 status, if the application is not found.By default, this flag is set to true.

What is spring cloud config?

At the time of developing our application is going from development to testing environment and then it will be going into the production environment, we can manage configuration in all environment using spring boot config, also it will manage all the thing which was required for the application for transferring it from one environment to another environment..

Creating spring cloud config

First, we need to setup config server after creating config server we need to build the client which was used to consume the configuration at the time of server startup.

Server uses SSH configuration and properties

We can also use SSH configuration in the spring cloud config project. JGit requires the PEM format RSA keys.

Conclusion

Spring cloud config is nothing but the client and server approach which was used for serving distributed configuration. Using spring cloud config we can manage the external properties of all applications. Spring cloud config is providing support of externalized configuration for server side and client-side system which was distributed.

What is Spring Cloud Config Server?

Spring Cloud Config Server provides an HTTP resource-based API for external configuration (name-value pairs or equivalent YAML content). The server is embeddable in a Spring Boot application, by using the @EnableConfigServerannotation. Consequently, the following application is a config server:

What port does Spring Boot use?

Why do I need to clone a repository?

What is aws-java-sdk-corejar?

The aws-java-sdk-corejar is an optional dependency. If the aws-java-sdk-corejar is not on your classpath, the AWS Code Commit credential provider is not created, regardless of the git server URI.

Does Spring Cloud Config Server have a git repository?

Can you set Spring Cloud to accept empty?

You can set spring.cloud.config.server.accept-empty to false so that Server would return a HTTP 404 status, if the application is not found.By default, this flag is set to true.

Does Spring Cloud Config Server support AWS CodeCommit?

Spring Cloud Config Server also supports AWS CodeCommitauthentication. AWS CodeCommit uses an authentication helper when using Git from the command line. This helper is not used with the JGit library, so a JGit CredentialProvider for AWS CodeCommit is created if the Git URI matches the AWS CodeCommit pattern. AWS CodeCommit URIs follow this pattern://git-codecommit.${AWS_REGION}.amazonaws.com/${repopath}.

What is the name of the configuration file?

The name of the configuration file is composed like a normal Spring application.properties, but instead of the word ‘application' a configured name, e.g. the value of the property ‘spring.application.name' of the client is used, followed by a dash and the active profile. For example:

When setting up a repository containing YAML files, do you have to surround your encrypted and prefixed values?

Tip: When setting-up a repository containing YAML files, you have to surround your encrypted and prefixed values with single-quotes! With Properties this is not the case.

Can configuration store be modified?

This configuration store is ideally versioned under Git version control and can be modified at application runtime. While it fits very well in Spring applications using all the supported configuration file formats together with constructs like Environment, PropertySource or @Value, it can be used in any environment running any programming language.

Can you embed a config server into an application?

Embed the config server into an application, where it configures itself from a Git repository, instead of running as standalone application serving clients. Therefore some bootstrap properties must be set and/or the @EnableConfigServer annotation must be removed, which depends on the use case.

Often-Changing Configurations

A famous pro-argument of some users is that you can reload your Spring configuration without restarting or redeploying. For me, there are two things that should be thought about when it comes to this significant use-case:

Configs for different Profiles

Another argument for a cloud config server is having different profiles, e.g. for different environments or multiple tenants. Spring is already capable of managing configuration for different profiles very well, and it has excellent documentation…

Better Alternatives

Management of your application configuration is a concern that should be handled by or near your infrastructure and deployment. Most cloud and hosting infrastructures provide excellent configuration management by using environment variables or injecting configuration files.

Final Words

I personally only see very rare use-cases where Spring Cloud Config adds real value today. Especially when you’re hosting in a private or public cloud, you should consider using its onboard configuration management mechanisms. They are often way more powerful than a config-server, without adding dependencies.

The app

We’ll build a small application that provides a Rest API to generate text messages. The templates for these messages will be configured in configuration files, hosted in a remote repository, which will be read by a configuration server. The infrastructure of our application will be as follows:

Rest API

First, we will build a simple application providing only 2 endpoints, one of them will be responsible for generating a welcome message, and the other will be responsible for generating a goodbye message. Our application will be named text-message-generator and initially, we will build it with Spring Web and Lombok dependencies.

Text Message Generator Configuration

Now let’s configure the name and port of our application, we’ll leave our application.yml (or application.properties) file as follows:

Remote configurations repository

We will create a remote repository on GitHub (for educational purposes we will create it as a public repository). Our repository will only have a folder containing two configuration files, one for the development environment and one for the production environment.

Configuration server

What we will do now is to create an independent application, which will be our configuration server, this application will read the configurations that will be hosted in our Remote repository.

Integrating the two projects

Now we need to make our API that generates messages, ask the configuration server for the message templates already configured in our remote repository. To do this, we will need to add the Spring Cloud Config Client dependency to our text-message-generator project, considering our project will be a client of our config server.

Spring Boot Actuator

If you want to be able to update the settings without the need to restart the server, you can use Spring Boot Actuator to perform this job. To do this, simply add the dependency of the Spring Boot Actuator in the POM.XML of the text-message-generator project: