Backport from branch opendistro-1.12.0.0 to 7.9.1

[zhongnansu]

Issue #, if available:

Description of changes:

• Cherry-pick commits except [reports-scheduler] Add support for Elasticsearch 7.10.0 #203 [Kibana-reports]Add support for Kibana 7.10.0 #205 which is a version upgrade from 7.9.1 to 7.10.0
• fix some conflicts that relates to 7.10 in other commits
• change the constant LOCAL_HOST from 5601 to 9200 for AES
• add a constant BASE_PATH = "/_plugin/kibana" for AES
• use patch release common-utils:1.11.1.0 in build.gradle

TODO

• come up a solution to close the code gap between AES and OD. Need to use plugin-config for at least port and basePath. This will also remove the limitation of current reporting on OD, where reporting only works if user use default server.basePath and server.port in Kibana.yml. The code change should be pushed to dev branch and backport to 7.9.1 branch if needed.

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[davidcui1225]

LGTM

[joshuali925]

@zhongnansu looks like basepath can be retrieved from core.http.basePath.get(request) or core.http.basePath.serverBasePath
https://github.com/elastic/kibana/blob/v7.9.1/src%2Fcore%2Fserver%2Fhttp%2Fbase_path_service.ts#L31-L36

and port is core.http.getServerInfo().port
https://github.com/elastic/kibana/blob/v7.9.1/src%2Fcore%2Fserver%2Fhttp%2Ftypes.ts#L272-L275

if they don't work maybe read from frontend url or ping a few possible localhost:<port>/<path>/api/status to see which one responds?

[zhongnansu]

core.http.basePath.serverBasePath

Good point! I wasn't able to find how to access port before. Your solution sounds promising, the only thing left is to rebuild the input validation for the relative url. Do you know if there is a way to expose basePath to UI, or access basePath from UI code? Basically, we need to clean the url from UI before passing to server, so that the old input validation will work and robust with minor modification

[joshuali925]

That will be part of the basename here. I think it would be something like /basepath/app/opendistro-reports, you can get Kibana server.basepath if you remove the plugin path.

[ylasri]

Hi @zhongnansu

Only some parameters from Kibana.yml are exposed via CoreSetup

• server.port
• server.host
• server.name
• server.basePath

Theses parameters can be accessed as follow from any server method that has CoreSetup as a parameter

  const { protocol, port, hostname, name } = core.http.getServerInfo();
  const basePath = core.http.basePath.serverBasePath;

core.http.getServerInfo() is type of HttpServerInfo 

/** @public */
export interface HttpServerInfo {
  /** The name of the Kibana server */
  name: string;
  /** The hostname of the server */
  hostname: string;
  /** The port the server is listening on */
  port: number;
  /** The protocol used by the server */
  protocol: 'http' | 'https' | 'socket';
}

The CoreSetup can instance is the one used at the server level plugin initilization

public setup(core: CoreSetup) {
  ....
  //Register server side APIs
  registerRoutes(router, core);
  ....
}