Mastering CRUD Operations with OpenSearch in Python: A Practical Guide-Python教程-PHP中文网

Mastering CRUD Operations with OpenSearch in Python: A Practical Guide

OpenSearch, an open-source alternative to Elasticsearch, is a powerful search and analytics engine built to handle large datasets with ease. In this blog, we’ll demonstrate how to perform basic CRUD (Create, Read, Update, Delete) operations in OpenSearch using Python.

Prerequisites:

Python 3.7+
OpenSearch installed locally using Docker
Familiarity with RESTful APIs

Step 1: Setting Up OpenSearch Locally with Docker

To get started, we need a local OpenSearch instance. Below is a simple docker-compose.yml file that spins up OpenSearch and OpenSearch Dashboards.

version: '3'
services:
  opensearch-test-node-1:
    image: opensearchproject/opensearch:2.13.0
    container_name: opensearch-test-node-1
    environment:
      - cluster.name=opensearch-test-cluster
      - node.name=opensearch-test-node-1
      - discovery.seed_hosts=opensearch-test-node-1,opensearch-test-node-2
      - cluster.initial_cluster_manager_nodes=opensearch-test-node-1,opensearch-test-node-2
      - bootstrap.memory_lock=true
      - "OPENSEARCH_JAVA_OPTS=-Xms512m -Xmx512m"
      - "DISABLE_INSTALL_DEMO_CONFIG=true"
      - "DISABLE_SECURITY_PLUGIN=true"
    ulimits:
      memlock:
        soft: -1
        hard: -1
      nofile:
        soft: 65536
        hard: 65536
    volumes:
      - opensearch-test-data1:/usr/share/opensearch/data
    ports:
      - 9200:9200
      - 9600:9600
    networks:
      - opensearch-test-net

  opensearch-test-node-2:
    image: opensearchproject/opensearch:2.13.0
    container_name: opensearch-test-node-2
    environment:
      - cluster.name=opensearch-test-cluster
      - node.name=opensearch-test-node-2
      - discovery.seed_hosts=opensearch-test-node-1,opensearch-test-node-2
      - cluster.initial_cluster_manager_nodes=opensearch-test-node-1,opensearch-test-node-2
      - bootstrap.memory_lock=true
      - "OPENSEARCH_JAVA_OPTS=-Xms512m -Xmx512m"
      - "DISABLE_INSTALL_DEMO_CONFIG=true"
      - "DISABLE_SECURITY_PLUGIN=true"
    ulimits:
      memlock:
        soft: -1
        hard: -1
      nofile:
        soft: 65536
        hard: 65536
    volumes:
      - opensearch-test-data2:/usr/share/opensearch/data
    networks:
      - opensearch-test-net

  opensearch-test-dashboards:
    image: opensearchproject/opensearch-dashboards:2.13.0
    container_name: opensearch-test-dashboards
    ports:
      - 5601:5601
    expose:
      - "5601"
    environment:
      - 'OPENSEARCH_HOSTS=["http://opensearch-test-node-1:9200","http://opensearch-test-node-2:9200"]'
      - "DISABLE_SECURITY_DASHBOARDS_PLUGIN=true"
    networks:
      - opensearch-test-net

volumes:
  opensearch-test-data1:
  opensearch-test-data2:

networks:
  opensearch-test-net:

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Run the following command to bring up your OpenSearch instance:
docker-compose up
OpenSearch will be accessible at http://localhost:9200.

Step 2: Setting Up the Python Environment

python -m venv .venv
source .venv/bin/activate
pip install opensearch-py

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We'll also structure our project as follows:

├── interfaces.py
├── main.py
├── searchservice.py
├── docker-compose.yml

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Step 3: Defining Interfaces and Resources (interfaces.py)

In the interfaces.py file, we define our Resource and Resources classes. These will help us dynamically handle different resource types in OpenSearch (in this case, users).

from dataclasses import dataclass, field

@dataclass
class Resource:
    name: str

    def __post_init__(self) -> None:
        self.name = self.name.lower()

@dataclass
class Resources:
    users: Resource = field(default_factory=lambda: Resource("Users"))

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Step 4: CRUD Operations with OpenSearch (searchservice.py)

In searchservice.py, we define an abstract class SearchService to outline the required operations. The HTTPOpenSearchService class then implements these CRUD methods, interacting with the OpenSearch client.

# coding: utf-8

import abc
import logging
import typing as t
from dataclasses import dataclass
from uuid import UUID

from interfaces import Resource, Resources
from opensearchpy import NotFoundError, OpenSearch

resources = Resources()


class SearchService(abc.ABC):
    def search(
        self,
        kinds: t.List[Resource],
        tenants_id: UUID,
        companies_id: UUID,
        query: t.Dict[str, t.Any],
    ) -> t.Dict[t.Literal["hits"], t.Dict[str, t.Any]]:
        raise NotImplementedError

    def delete_index(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
        data: t.Dict[str, t.Any],
    ) -> None:
        raise NotImplementedError

    def index(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
        data: t.Dict[str, t.Any],
    ) -> t.Dict[str, t.Any]:
        raise NotImplementedError

    def delete_document(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
        document_id: str,
    ) -> t.Optional[t.Dict[str, t.Any]]:
        raise NotImplementedError

    def create_index(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
        data: t.Dict[str, t.Any],
    ) -> None:
        raise NotImplementedError


@dataclass(frozen=True)
class HTTPOpenSearchService(SearchService):
    client: OpenSearch

    def _gen_index(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
    ) -> str:
        return (
            f"tenant_{str(UUID(str(tenants_id)))}"
            f"_company_{str(UUID(str(companies_id)))}"
            f"_kind_{kind.name}"
        )

    def index(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
        data: t.Dict[str, t.Any],
    ) -> t.Dict[str, t.Any]:
        self.client.index(
            index=self._gen_index(kind, tenants_id, companies_id),
            body=data,
            id=data.get("id"),
        )
        return data

    def delete_index(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
    ) -> None:
        try:
            index = self._gen_index(kind, tenants_id, companies_id)
            if self.client.indices.exists(index):
                self.client.indices.delete(index)
        except NotFoundError:
            pass

    def create_index(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
    ) -> None:
        body: t.Dict[str, t.Any] = {}
        self.client.indices.create(
            index=self._gen_index(kind, tenants_id, companies_id),
            body=body,
        )

    def search(
        self,
        kinds: t.List[Resource],
        tenants_id: UUID,
        companies_id: UUID,
        query: t.Dict[str, t.Any],
    ) -> t.Dict[t.Literal["hits"], t.Dict[str, t.Any]]:
        return self.client.search(
            index=",".join(
                [self._gen_index(kind, tenants_id, companies_id) for kind in kinds]
            ),
            body={"query": query},
        )

    def delete_document(
        self,
        kind: Resource,
        tenants_id: UUID,
        companies_id: UUID,
        document_id: str,
    ) -> t.Optional[t.Dict[str, t.Any]]:
        try:
            response = self.client.delete(
                index=self._gen_index(kind, tenants_id, companies_id),
                id=document_id,
            )
            return response
        except Exception as e:
            logging.error(f"Error deleting document: {e}")
            return None

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Step 5: Implementing CRUD in Main (main.py)

In main.py, we demonstrate how to:

Create an index in OpenSearch.

Index documents with sample user data.

Search for documents based on a query.

Delete a document using its ID.

main.py

# coding=utf-8

import logging
import os
import typing as t
from uuid import uuid4

import searchservice
from interfaces import Resources
from opensearchpy import OpenSearch

resources = Resources()

logging.basicConfig(level=logging.INFO)

search_service = searchservice.HTTPOpenSearchService(
    client=OpenSearch(
        hosts=[
            {
                "host": os.getenv("OPENSEARCH_HOST", "localhost"),
                "port": os.getenv("OPENSEARCH_PORT", "9200"),
            }
        ],
        http_auth=(
            os.getenv("OPENSEARCH_USERNAME", ""),
            os.getenv("OPENSEARCH_PASSWORD", ""),
        ),
        use_ssl=False,
        verify_certs=False,
    ),
)

tenants_id: str = "f0835e2d-bd68-406c-99a7-ad63a51e9ef9"
companies_id: str = "bf58c749-c90a-41e2-b66f-6d98aae17a6c"
search_str: str = "frank"
document_id_to_delete: str = str(uuid4())

fake_data: t.List[t.Dict[str, t.Any]] = [
    {"id": document_id_to_delete, "name": "Franklin", "tech": "python,node,golang"},
    {"id": str(uuid4()), "name": "Jarvis", "tech": "AI"},
    {"id": str(uuid4()), "name": "Parry", "tech": "Golang"},
    {"id": str(uuid4()), "name": "Steve", "tech": "iOS"},
    {"id": str(uuid4()), "name": "Frank", "tech": "node"},
]

search_service.delete_index(
    kind=resources.users, tenants_id=tenants_id, companies_id=companies_id
)

search_service.create_index(
    kind=resources.users,
    tenants_id=tenants_id,
    companies_id=companies_id,
)

for item in fake_data:
    search_service.index(
        kind=resources.users,
        tenants_id=tenants_id,
        companies_id=companies_id,
        data=dict(tenants_id=tenants_id, companies_id=companies_id, **item),
    )

search_query: t.Dict[str, t.Any] = {
    "bool": {
        "must": [],
        "must_not": [],
        "should": [],
        "filter": [
            {"term": {"tenants_id.keyword": tenants_id}},
            {"term": {"companies_id.keyword": companies_id}},
        ],
    }
}
search_query["bool"]["must"].append(
    {
        "multi_match": {
            "query": search_str,
            "type": "phrase_prefix",
            "fields": ["name", "tech"],
        }
    }
)

search_results = search_service.search(
    kinds=[resources.users],
    tenants_id=tenants_id,
    companies_id=companies_id,
    query=search_query,
)

final_result = search_results.get("hits", {}).get("hits", [])
for item in final_result:
    logging.info(["Item -> ", item.get("_source", {})])

deleted_result = search_service.delete_document(
    kind=resources.users,
    tenants_id=tenants_id,
    companies_id=companies_id,
    document_id=document_id_to_delete,
)
logging.info(["Deleted result -> ", deleted_result])

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Step 6: Running the project

docker compose up
python main.py

Results:

It should print found & deleted records information.

Step 7: Conclusion

In this blog, we’ve demonstrated how to set up OpenSearch locally using Docker and perform basic CRUD operations with Python. OpenSearch provides a powerful and scalable solution for managing and querying large datasets. While this guide focuses on integrating OpenSearch with dummy data, in real-world applications, OpenSearch is often used as a read-optimized store for faster data retrieval. In such cases, it is common to implement different indexing strategies to ensure data consistency by updating both the primary database and OpenSearch concurrently.

This ensures that OpenSearch remains in sync with your primary data source, optimizing both performance and accuracy in data retrieval.

References:

https://github.com/FranklinThaker/opensearch-integration-example

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