Basic Delete Example

This sample deletes a document from an Elasticsearch server via the Elasticsearch Delete API and displays the results of the delete request.

For more information on the Elasticsearch Delete API, see the Elasticsearch Python Delete API and Elasticsearch REST Delete API documentation.

Prerequisites

• The samples configuration step has been completed (see Samples Configuration).

• The Elasticsearch API DXL service is running (see Elasticsearch DXL Service).

• In order to enable the use of the delete API, the API name needs to be listed in the apiNames setting under the [General] section in the "dxlelasticsearchservice.config" file that the service uses:

  [General]
  apiNames=delete,...
  

  For more information on the configuration, see the Elasticsearch DXL Python Service configuration documentation.

• Run through the steps in the Basic Index Example to store a document to Elasticsearch. This example will delete the stored document.

Running

To run this sample execute the sample/basic/basic_delete_example.py script as follows:

python sample/basic/basic_delete_example.py

If the document was previously stored via running the Basic Index Example, the output should appear similar to the following:

Response from delete:
{
    "_id": "12345",
    "_index": "opendxl-elasticsearch-client-examples",
    "_shards": {
        "failed": 0,
        "successful": 2,
        "total": 2
    },
    "_type": "basic-example-doc",
    "_version": 2,
    "found": true,
    "result": "deleted"
}

If the document to be deleted does not exist on the Elasticsearch server at the time the sample is run, the output should appear similar to the following:

Requested document was not found on the server

Details

The majority of the sample code is shown below:

# Create the client
with DxlClient(config) as dxl_client:

    # Connect to the fabric
    dxl_client.connect()

    logger.info("Connected to DXL fabric.")

    # Create client wrapper
    client = ElasticsearchClient(dxl_client)

    try:
        # Invoke the delete method
        resp_dict = client.delete(
            index=DOCUMENT_INDEX,
            doc_type=DOCUMENT_TYPE,
            id=DOCUMENT_ID)

        # Print out the response (convert dictionary to JSON for pretty
        # printing)
        print("Response from delete:\n{0}".format(
            MessageUtils.dict_to_json(resp_dict, pretty_print=True)))
    except NotFoundError:
        print("Requested document was not found on the server")

Once a connection is established to the DXL fabric, a dxlelasticsearchclient.client.ElasticsearchClient instance is created which will be used to invoke remote commands on the Elasticsearch DXL service.

Next, the dxlelasticsearchclient.client.ElasticsearchClient.delete() method is invoked with the index, type (doc_type), and id of the document to delete.

From the Elasticsearch Python Delete API documentation:

"Delete a typed JSON document from a specific index based on its id."

If the document to be deleted does not exist on the Elasticsearch server at the time the sample is run, the delete method will raise an elasticsearch.exceptions.NotFoundError exception. In this case, the sample catches the exception, displays an error message, and exits.

If the document to be deleted does exist on the Elasticsearch server at the time the sample is run, the final step is to display the contents of the returned dictionary (dict) which contains the results of the attempt to delete the document.