@kbn/core-data-streams-server

Motivation

While its possible to use @kbn/data-streams as a standalone package by passing an appropriate esClient object during inititalize() (to handle communication with Elasticsearch), the core data streams service allows for a coordinated initialization of your data stream indices as part of the CoreSetup and CoreStart plugin initalization routine.

Some additional benefits to using the core data streams service:

You no longer have to pass the privileged kibana es client (core.elasticsearch.client.asInternalUser), but can rely on the internal behavior of this service during initializeAllDataStreams() which will take care of passing it as soon as its available.
Core can coordinate updates to existing data streams a bit better i.e. avoid a flood of requests from multi Kibana clusters
Change detection data streams are easier to detect/keep track of via Core registrations

Examples

Please refer to examples/data_streams_example/server/index.ts

export const plugin = (ctx: PluginInitializerContext) => {
  return {
    setup({ dataStreams }: CoreSetup) {
      dataStreams.registerDataStream(dataStream);
    },
    start({ dataStreams }: CoreStart) {
      const initializeClient = async () => {
        return await dataStreams.initializeClient<typeof dataStreamMappings, DataStreamDocument>(
          dataStream.name
        );
      };
      return {
        createSpecialDocument: async () => {
          const client = await initializeClient();
          const document: DataStreamDocument = {
            '@timestamp': +new Date(),
            name: 'John Doe',
            description: 'This is a test document for my data stream.',
            age: 30,
            unMappedField: 'Unmapped field but exists in the document _source',
          };

          const result = await client.create({
            documents: [document],
          });

          ctx.logger.get('data-streams-example').info(JSON.stringify(result, null, 2));
        },
        getDocument: async (id: string) => {
          const client = await initializeClient();

          const result = await client.search({
            query: {
              term: { description: 'This is a test document for my data stream.' },
            },
          });

          return result;
        },
      };
    },
    stop() {},
  };
};