Inherit AwsSigV4 in .child

[bandinib-amzn]

Description

There are some use cases where you may need multiple instances of the client. You can easily do that by calling new Client() as many times as you need, but you will lose all the benefits of using one single client, such as the long living connections and the connection pool handling.

As of today, we have client.child API, which returns a new client instance that shares the connection pool with the parent client. But this only supported for Basic Authentication type (with username and password). This PR adds the child client support for AWSSigv4.

Example:

const client = new Client({
  ...AwsSigv4Signer({
    region: 'us-west-2',
    service: 'es',
    getCredentials: () =>
      new Promise((resolve, reject) => {
        AWS.config.getCredentials((err, credentials) => {
          if (err) {
            reject(err);
          } else {
            resolve(credentials);
          }
        });
      }),
  }),
  node: 'https://search-xxx.region.es.amazonaws.com', // OpenSearch domain URL
});

const child = client.child({
  auth: {
        credentials: {
          accessKeyId: 'foo',
          secretAccessKey: 'bar',
          sessionToken: 'foobar',
        },
        region: 'eu-west-1',
        service: 'es',
      }
});

Issues Resolved

#696

Check List

• New functionality includes testing.
  • All tests pass
• Linter check was successfull - yarn run lint doesn't show any errors
• Commits are signed per the DCO using --signoff
• Changelog was updated.

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[seraphjiang]

Thanks @bandinib-amzn would you explain what's usage for this enhancement. e.g. support what feature in OSD. and targeting which version of OSD release.

@ananzh @kavilla @dblock and team would you help to take a look.

[seraphjiang]

@Flyingliuhub @BionIT @ZilongX @zengyan-amazon would you also help to take a look.

[dblock]

LGTM, just needs that console.log removed

[Flyingliuhub]

getCredentialsCalled and count are used similarly to track the count. Should we use a consistent name, or should we make count more meaningful name here?

[bandinib-amzn]

getCredentialsCalled is tracking how many times getCredentials function called. and count is tracking requests. I would keep count to be consistent with other UT.

[bandinib-amzn]

Thanks @bandinib-amzn would you explain what's usage for this enhancement. e.g. support what feature in OSD. and targeting which version of OSD release.

@ananzh @kavilla @dblock and team would you help to take a look.

We already have the client.child API, which returns a new client instance that shares the connection pool with the parent client. However, this feature is currently only supported for Basic Authentication (with username and password). This pull request incorporates the AwsSigV4 functionality into .child. Utilizing connection pooling offers numerous benefits, including connection reuse and recycling.

In OpenSearch-Dashboards, when utilizing the multi-data source feature to create data sources, we employ the opensearch-js library to instantiate the client. Currently, we leverage .child for basic authentication, as demonstrated here.

However, similar support for AWSSigV4 has not been implemented, necessitating the creation of a new client every time. With this modification, we can generate multiple child clients from the same parent client (on the same node and SSL) by passing credentials via auth.

We are targeting OSD 2.13 release. @dblock How is the release schedule look like for opensearch-js? Thanks!