Show HN: MongoDB on Cloudflare Workers with Do

2 hours ago 1

Example showing how to use mongodb with cloudflare workers with durable object for improved speed and reusable connection. During development, it uses original mongodb api calls without DO as durable object not supported in open-next dev. All the mongodb files present in lib/mongo folder.

Make sure to configure these .env variables for mongodb via wrangler secret put <ENV_NAME> or via cloudflare dashboard.

It also support sharding in durable object to bypass 1K/sec limitation although not required. Currently it set to 2 and you can configure the variable on lib/mongo/index.ts file (line 58: NUMBER_OF_DO_SHARDS)

Using mongodb transaction

Check api/hc/route.ts file for transaction usage.

FindCursor.ts - Contains the FindCursor class
AggregateCursor.ts - Contains the AggregateCursor class
types.ts - Contains shared interface definitions

import { getCollection } from '@/lib/mongo'; const collection = getCollection('myCollection'); // Basic find with cursor methods const docs = await collection.find({ status: 'active' }) .limit(10) .skip(5) .sort({ createdAt: -1 }) .toArray(); // With projection const docsWithProjection = await collection.find({ status: 'active' }) .project({ title: 1, description: 1, _id: 0 }) .limit(20) .toArray();

// Basic aggregation with cursor methods const results = await collection.aggregate([ { $match: { status: 'published' } } ]) .sort({ views: -1 }) .limit(10) .project({ title: 1, views: 1 }) .toArray(); // Complex aggregation pipeline const complexResults = await collection.aggregate([ { $match: { category: 'tech' } } ]) .group({ _id: '$author', totalViews: { $sum: '$views' }, articleCount: { $sum: 1 } }) .sort({ totalViews: -1 }) .limit(5) .toArray(); // Using native MongoDB aggregation operators const lookupResults = await collection.aggregate([ { $match: { status: 'active' } } ]) .lookup({ from: 'users', localField: 'authorId', foreignField: '_id', as: 'author' }) .unwind('$author') .project({ title: 1, 'author.name': 1, publishedAt: 1 }) .sort({ publishedAt: -1 }) .limit(20) .toArray();

Chaining Multiple Methods

// Complex query with multiple cursor methods const result = await collection.find({ category: 'tech' }) .sort({ publishedAt: -1, views: -1 }) .skip(10) .limit(5) .project({ title: 1, summary: 1, views: 1 }) .toArray(); // Async iteration support for await (const doc of collection.find({ status: 'active' }).limit(100)) { console.log(doc.title); }

// Using various cursor options const docs = await collection.find({ status: 'active' }) .sort({ createdAt: -1 }) .limit(20) .batchSize(5) .maxTimeMS(5000) .hint({ status: 1, createdAt: -1 }) .collation({ locale: 'en', strength: 2 }) .allowDiskUse(true) .toArray(); // Aggregation with options const aggResults = await collection.aggregate([ { $match: { views: { $gte: 100 } } } ]) .sort({ views: -1 }) .limit(10) .allowDiskUse(true) .maxTimeMS(10000) .batchSize(5) .toArray();