Introduce getConfig QoS Command

[AlbumenJ]

What is the purpose of the change

Add getConfig command to get config in runtime

Examples:

1. getConfig
2. getConfig ApplicationConfig
3. getConfig ReferenceConfig com.example.DemoService

➜  dubbo-samples git:(apache-master) ✗ telnet 127.0.0.1 22222
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
   ___   __  __ ___   ___   ____     
  / _ \ / / / // _ ) / _ ) / __ \  
 / // // /_/ // _  |/ _  |/ /_/ /    
/____/ \____//____//____/ \____/   
dubbo>getConfig
ApplicationModel: Dubbo Application[1.1](first-dubbo-provider)
ApplicationConfig: first-dubbo-provider
<dubbo:application enableFileCache="true" executorManagementMode="default" environment="product" parameters="{}" name="first-dubbo-provider" protocol="dubbo" />

ProtocolConfig: dubbo
<dubbo:protocol preferSerialization="fastjson2,hessian2" port="-1" name="dubbo" />

RegistryConfig: null
<dubbo:registry address="nacos://127.0.0.1:8848" protocol="nacos" port="8848" />

MetadataReportConfig: null
<dubbo:metadata-report address="nacos://127.0.0.1:8848" protocol="nacos" port="8848" parameters="{client=null}" />

ConfigCenterConfig: config-center-nacos-127.0.0.1-8848
<dubbo:config-center configFile="dubbo.properties" namespace="dubbo" group="dubbo" highestPriority="false" id="config-center-nacos-127.0.0.1-8848" timeout="30000" address="nacos://127.0.0.1:8848" protocol="nacos" check="true" port="8848" parameters="{client=null}" />

SslConfig: null
<dubbo:ssl />

ModuleModel: Dubbo Module[1.1.0]
ProviderConfig: null
<dubbo:provider deprecated="false" dynamic="true" />

ConsumerConfig: null
<dubbo:consumer sticky="false" />

ModuleConfig: null
<dubbo:module background="false" />

ModuleModel: Dubbo Module[1.1.1]
ProviderConfig: null
<dubbo:provider deprecated="false" dynamic="true" />

ConsumerConfig: null
<dubbo:consumer sticky="false" />

ModuleConfig: null
<dubbo:module background="false" />

ServiceConfig: org.apache.dubbo.samples.api.GreetingsService
<dubbo:service path="org.apache.dubbo.samples.api.GreetingsService" deprecated="false" dynamic="true" generic="false" ref="org.apache.dubbo.samples.provider.GreetingsServiceImpl@b2843cb" interface="org.apache.dubbo.samples.api.GreetingsService" />


dubbo>

Brief changelog

Verifying this change

Checklist

• Make sure there is a GitHub_issue field for the change (usually before you start working on it). Trivial changes like typos do not require a GitHub issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
• Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Check if is necessary to patch to Dubbo 3 if you are work on Dubbo 2.7
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Add some description to dubbo-website project if you are requesting to add a feature.
• GitHub Actions works fine on your own branch.
• If this contribution is large, please follow the Software Donation Guide.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

94.0% Coverage
0.0% Duplication

[AlbumenJ]

@chickenlj PTAL

[chickenlj]

I think this can be a handy tool for quickly investigating the effective configuration when there are problems hard to judge from logs.