Design doc

Design goal and decision

1. Seamless Spring Cloud integration with Azure. Users can easily adopt Azure services without having to modify existing code. Only dependencies and a few configuration settings are needed.
2. Least configuration. This is done by taking advantage of Spring boot auto config to preconfigure default properties values based on Azure Resource Management API. Users can override these properties with their own.
3. Provision resource automatically. If resources are not existed, our modules will create them under user specified subscription and resource group.
4. No cloud vendor lock in. With our modules, users can easily consume Azure services as well as benefit from conveniences provided by Spring Cloud, without getting locked in with one specific cloud vendor.

Spring Cloud Azure Starter vs Spring Azure Starter vs Spring Boot Starter

Simply, these starters are ordered in decreasing level of abstraction, from high to low. But even if you choose the high level, you still have freedom to manipulate in low level.

1. Spring Cloud Azure Starter has prefix spring-cloud-azure-starter. These starters rely on high level abstraction provided by Spring Cloud. They use azure credential to do auto config and hide low level details of Azure SDK. They also provide automatic resource provision. For example, to use spring-cloud-azure-starter-servicebus, you just need to provide service bus namespace in property and use spring cloud stream abstraction to produce and consume message.
2. Spring Azure Starter has prefix spring-azure-starter. These starters rely on abstraction provided by Spring. They use azure credential to do auto config and hide low level details of Azure SDK. They also provide automatic resource provision. For example, to use spring-azure-starter-storage, you just need to provide storage account name in property and rely on Resource abstraction provided by Spring.
3. Spring Boot Starter has suffix spring-boot-starter. These starters rely on low level details of Azure SDK and some azure service specific property. For example, to use azure-storage-spring-boot-starter, you need to understand connection string in property and rely on CloudStorageAccount.

Our suggestion is try to use Spring Cloud Azure Starter or Spring Azure Starter unless your project already rely on low level Azure SDK.

Planned feature

Feature	Azure Service	Description	Status
Spring cloud Cache Starter	Redis	Auto config of redis properties
Spring cloud Resource	Storage account	Mapping storage as Spring resource
Spring cloud JDBC starter	Sql Database Mysql PostgreSql	Auto config of sql database
Spring cloud messaging	Event Hub Service Bus Queue Storage Notification Hub	Inbound and outbound adapter for consuming and producing message
Spring cloud stream binder	Event Hub	Event hub binder to provide as many function as Kafka
Spring cloud stream starter	Kafka-HDInsight Event Hub with Kafka API	Auto config of Kafka properties
Spring cloud CosmosDB starter	Cosmos DB	Auto config of connection properties and Spring Data CosmosDB
Spring cloud logging starter	Application Insight	Auto config of logger
Spring cloud trace	Applcation Insight	Auto config of sending trace
Spring Hadoop starter	Hadoop(HDInisght)	Auto config of hadoop
Spring mail	SendGrid	Auto config of mail service	Blocked on no Azure management API
Spring cloud Function	Azure Function	Auto config of Azure Function