1. Using the MongoDB aggregation pipeline for complex querying

    TypeScript

    The MongoDB aggregation pipeline is a powerful feature provided by MongoDB that allows you to perform complex data processing and transformation on your MongoDB collections. It can handle tasks such as filtering, projecting, grouping, sorting, and joining documents, amongst other operations, enabling you to execute complex queries and data analysis.

    In terms of working with MongoDB in a cloud environment, Pulumi provides resources for deploying and managing MongoDB instances. Specifically, the azure.cosmosdb.MongoCollection resource can be used as a part of Azure Cosmos DB's API for MongoDB which supports the MongoDB aggregation pipeline.

    Below is a program written in TypeScript that creates a MongoDB collection in Azure Cosmos DB using Pulumi. This collection can then be used to leverage MongoDB's aggregation pipeline.

    Let's walk through the Pulumi program that sets up an Azure Cosmos DB account, a MongoDB database within it, and then creates a collection:

    import * as pulumi from "@pulumi/pulumi"; import * as azure from "@pulumi/azure"; // Create an Azure Resource Group const resourceGroup = new azure.core.ResourceGroup("myResourceGroup", { location: "West US", }); // Create an Azure DocumentDB (CosmosDB) account const dbAccount = new azure.cosmosdb.Account("myDocumentdbAccount", { resourceGroupName: resourceGroup.name, location: resourceGroup.location, offerType: "Standard", kind: "MongoDB", capabilities: [ { name: "EnableAggregationPipeline", }, ], consistencyPolicy: { consistencyLevel: "Session", }, geoLocations: [ { location: resourceGroup.location, failoverPriority: 0, }, ], }); // Create a MongoDB Database within the account const database = new azure.cosmosdb.MongoDatabase("myDatabase", { name: "databaseName", resourceGroupName: resourceGroup.name, accountName: dbAccount.name, throughput: 400, }); // Create a collection within the MongoDB database const collection = new azure.cosmosdb.MongoCollection("myCollection", { name: "collectionName", resourceGroupName: resourceGroup.name, accountName: dbAccount.name, databaseName: database.name, throughput: 400, shardKey: "myShardKey", }); // Export the connection string for the MongoDB instance for easy access export const connectionString = pulumi.all([dbAccount.name, database.name, collection.name]).apply( ([account, db, coll]) => `mongodb://${account}.documents.azure.com:10255/${db}/${coll}?ssl=true&replicaSet=globaldb` );

    Explanation:

    1. We start by importing the necessary packages from Pulumi.

    2. We create a new Azure Resource Group that will contain our Cosmos DB instance.

    3. We then create a Cosmos DB account configured for MongoDB usage. The offerType is set to Standard and the kind is set to MongoDB. We also enable the EnableAggregationPipeline capability, which allows us to use the MongoDB aggregation framework.

    4. We create a MongoDB Database within the Cosmos DB account. Here we assign throughput, which represents the performance level of the database.

    5. We create a MongoDB Collection inside the database we just created. We set the shardKey, which determines the distribution of data across partitions (if creating a sharded collection).

    6. Lastly, we export the connection string needed to connect to this MongoDB collection, formatted as a MongoDB URI, which includes the account, database, and collection names.

    Remember to install the Pulumi CLI, set up your Azure account, and configure Pulumi to use your Azure credentials. Once that's done, you can run this code using the Pulumi CLI to deploy this infrastructure.

    Keep in mind the connection string exported by this program should be treated as sensitive data and in practice, you might want to use secret management tools to handle such information securely.

    For more details on the resources used in this program, you can visit the documentation:

    This will set up the necessary infrastructure, and then you can perform your complex querying using the MongoDB aggregation pipeline on this collection.