AzureStorageBlobNode

Code related to Azure Storage Blob written in Node.js

Note

Only for dev.

Operations implemented

• createZipFromBlobs (Create zip stream from all blobs with prefix(in specific subfolder) to response in Node.JS Web App)

Prerequisite

• intall two related packages

npm install azure-storage
npm install archiver

• add storageConnectionString in createZipFromBlobs.js

How to use

• put this module in current folder(or any folder we want) and import it

var storageOperation = require('./createZipFromBlobs.js');

• call the method(use router as an example)

router.get('/', function(req, res){
    console.log("start read stream to zip res");
    storageOperation.createZipFromBlobs(res, "containerName", "prefix", parallelRequestCount);
});

Explanation

paralleRequestCount is optional, default is 100. It is used to restrict the parallel request count sent to Storage.

I use createReadStream method in azure-storage module, which is uesd to open read stream between Web and Storage.

Originally my code sends all requests(based on blob count, no limit) to Storage. I met ECONNREST error due to two many read stream are openned and can't be closed in time. So I planned to sent at most 5000 once(listblob method can get at most 5000 blobpath once), but I still got ECONNREST.

Finally I turn to control the request manually in code(a simple loop), with the parameter paralleRequestCount.

Last word

I am new to Node.JS, feel free to pull request if you find my code is full of flaws, thanks for your patience.