support Nacos cluster

[IanCao]

Please answer these questions before submitting pull request

• Why submit this pull request?

• Bug fix

• New feature provided

• Improve performance

• Related issues

---

Bug fix

• Bug description.

• How to fix?

---

New feature or improvement

• Describe the details and related test reports.

[wu-sheng]

Please check Nacos license issue first, then we could talk about this PR.

[IanCao]

There is something missing in the screenshot, could you provide the difference between before and after the nacos dependency? Which libs version update? Which libs are added?

the check result： five jars added, no jar's version update.
the five jar list:

1. cluster-nacos-plugin-6.2.0-SNAPSHOT.jar
2. fastjson-1.2.47.jar
3. nacos-api-1.0.0.jar
4. nacos-client-1.0.0.jar
5. nacos-common-1.0.0.jar

[IanCao]

i have updated the license, plz review

[wu-sheng]

SkyWalking dist LICENSE file has not been updated.

• Nacos lib should be included here, https://github.com/apache/skywalking/blob/master/apm-dist/release-docs/LICENSE#L310
• Fastjson lib should be included here, https://github.com/apache/skywalking/blob/master/apm-dist/release-docs/LICENSE#L220

[wu-sheng]

fastjson notice should be removed. It doesn't include more things than its license file.

[IanCao]

ok

[wu-sheng]

@peng-yongsheng Please recheck the document/LICENSE first, the new Nacos version with the exclusions should be good.

[peng-yongsheng]

Hi @IanCao, can you help me to correct some mistakes about not clear dependency management. I checked the dependency tree. And I found those third-party libraries are not managed by the OAP module's dependency manager, etc.. jackson-core, jackson-annotations, jackson-databind, commons-codec, commons-lang3.
This is not caused by you. Those libraries are not managed before. ^_^

[wu-sheng]

@peng-yongsheng could we change those through different pull request? Look like irrelevant.

[peng-yongsheng]

Image source

From this compile dependencies list, his exclude list is right and the third-party library's licenses are no problem. @wu-sheng

[peng-yongsheng]

@peng-yongsheng could we change those through different pull request? Look like irrelevant.

Those third-party libraries are using by gPRC and zookepper, but with different version. I'm not sure the OAP server is work well after the version changed.

[peng-yongsheng]

@peng-yongsheng could we change those through different pull request? Look like irrelevant.

@wu-sheng I think keeping those third-party libraries version is the best solution. He can only test the nacos client without test the whole OAP server. So, he can find the version number from current master source then put them into the dependency management.

[peng-yongsheng]

Waiting for dependency management.

[wu-sheng]

@peng-yongsheng I am just suggesting, we could try to work on another pull request to make sure the dependency clear for current master, then we update this pr.

[IanCao]

Hi @IanCao, can you help me to correct some mistakes about not clear dependency management. I checked the dependency tree. And I found those third-party libraries are not managed by the OAP module's dependency manager, etc.. jackson-core, jackson-annotations, jackson-databind, commons-codec, commons-lang3.
This is not caused by you. Those libraries are not managed before. ^_^

ok, i'll make the dependency management more clear and open a new pr to fix