[Epic] Improve test matrix to include all supported spring versions

[saragluna]

Context:

Currently Spring Cloud Azure supports multi Spring Boot and Spring Cloud versions, but those versions are not actively tested.
we need to figure out how to enable a testing matrix to actively test all support spring versions and Spring Cloud Azure libraries.

• Spring projects release monthly.
• Several types of libraries can be released from Spring projects, snapshot, prerelease, and GA.
• We use multiple Spring projects in Spring Cloud Azure: Spring Framework, Spring Boot, Spring Data, Spring Integration, Spring Cloud Stream, etc.

Strong has a poc for how to get dependency versions: https://github.com/Azure/spring-cloud-azure-tools/tree/t1/src/main/java/com/azure/spring/dev/tools/dependency

Goal:

The Spring Cloud Azure dev branch should align with Spring Boot on the current Spring Boot version.

• Spring Cloud Azure's source code dependency version should rely on the return value from https://spring.io/project_metadata/spring-boot with current: true.
• When the current version from https://spring.io/project_metadata/spring-boot changes, we should catch up ASAP.
• Track:
  • [FEATURE-REQ]Auto upgrade versions in Spring Cloud Azure to align with Spring Boot current version #5
  • Need to change the PR contents Update Github Actions #10

The Spring Cloud Azure dev branch should maintain a test matrix for dependent Spring projects. -- UT

• Spring Cloud Azure defines their supported Spring Boot versions,
  • The supported versions change along with Spring releases.
  • Such as supported-versions.json, listing 2.5.1 and 2.6.1 for example.
• Spring Cloud Azure tests on each milestone and GA releases of dependent Spring projects.
• Track:
  • [FEATURE-REQ] Provide new compatibility test for multiple Spring Boot version #7
  • Need to set different startup methods to start different test scopes [FEATURE REQ] Set up different usage scenarios for Spring Cloud Azure compatibility tests azure-sdk-for-java#29794

The Spring Cloud Azure should have integration tests, containing all Spring Cloud Azure libraries, to run against each version. -- IT

• Ideally, we can call Azure Spring Initializr to generate such a sample project and run it, expecting it throws no exceptions.
• If not the ideal case, we can write such a sample project (probably we put it in the SDK repo) and run it against each version. [FEATURE REQ]Add integration tests for Spring Cloud Azure azure-sdk-for-java#29717
  • Optional IT tasks will work on:
    • [FEATURE REQ]Add integration tests for Spring Cloud Azure autoconfigured keyvault certificates sdk client azure-sdk-for-java#30312
    • [FEATURE REQ] Add integration tests for Connectivity of spring-kafka with eventhubs azure-sdk-for-java#30313
    • [FEATURE REQ]Add integration tests for Connectivity of redis azure-sdk-for-java#30314
    • [FEATURE REQ] Support MI to connect Azure resources in Spring Cloud Azure ITs azure-sdk-for-java#30316
    • [FEATURE REQ] Support Multiple Spring Versions for Spring Cloud Azure ITs azure-sdk-for-java#30336
    • Azure AD IT

Solutions

• The Spring Cloud versions, should be parsed from API like curl -G https://start.spring.io/pom.xml -d packaging=war -o pom.xml and retrieved automatically
• The version matrix should be persistent somewhere, such as spring-cloud-azure-tools repo.

Originally posted by @saragluna in microsoft/spring-cloud-azure#930 (comment)

[saragluna]

1. The structure of (spring-cloud-azure-supported-spring.json) (temporary name)
   tools repo project produce a json file:

[
  {
	"current":  "true"  (unique in the list, should equal spring cloud azure source code)
	"spring-boot-version": "2.6.8"
	"spring-cloud-version": "2021.0.2"
	"releaseStatus": "SNAPSHOT",
	"snapshot": "true"
	"supportStatus": "endoflife | supported | todo" (our support information need manual maintenance)
										      (new entry is default to todo, and we can use another pipeline to test the supportability)
										      (spring metadata removes one version, we can try to create an issue to suggest/query whether we should mark the version to EoL(end of life))
  },
  {
	"current":  "true" 
	"spring-boot-version": "2.6.7"
	"spring-cloud-version": "2021.0.1"
	"releaseStatus": "SNAPSHOT",
	"snapshot": "true"
	"supportStatus": "endoflife | supported | todo"
  }
]

2. What's the JSON file should consist of?
   [history Spring project metadata] = [spring cloud azure json].

3. What will happen if a version is EoL but still returned from the Spring metadata?
   For example, 2.3.13 is end of life; we need to set its EOL manually.

4. If the tools output a JSON file, should the sdk pull the file, or should the tools create a PR to the sdk repo?
   tools: output a JSON

   • sdk pipeline pulls JSON from tools

     - It's easy, it only requires an HTTP call
     - this need the tools repo to be a public repo
     

   • tools push JSON to the sdk repo,

     - To create a PR to the SDK repo
     - The JSON represents our supportability
     - Spring Cloud Azure's supportability is traceable through PR
     - It's how azure-core Jackson does
     

5. If we detect a change in the value of current: true, what should we do?
   we need to create a PR to the sdk repo:

   • upgrade version_txt
   • upgrade versions