Azure Function NodeJS: blobService.createAppendBlobFromLocalFile Promise does not resolve - node.js

Question

I am new to azure functions and I am currently just trying to save an image as a blob to my storage. However, my Promise never resolve but the functions ends successfully. The image exists in my directory.
Here is my code so far:
module.exports = async function (context, req) {
const path = require('path');
const storage = require('azure-storage');
const STORAGE_ACCOUNT_NAME = 'something';
const ACCOUNT_ACCESS_KEY = 'also something';
const blobService = storage.createBlobService(STORAGE_ACCOUNT_NAME, ACCOUNT_ACCESS_KEY);
const filePath = './product-example.jpg';
function uploadLocalFile (filePath) {
return new Promise((resolve, reject) => {
const fullPath = path.resolve(filePath);
context.log('before call');
blobService.createAppendBlobFromLocalFile('productimageupload', 'image-upload-post', fullPath, function(err) {
if(err) {
context.log('err');
reject(err);
} else {
context.log('resolve');
resolve({message: 'resolved successfully'});
}
});
});
};
const output = uploadLocalFile(filePath);
context.log(output);
};
Here is the Protokoll output when executing the function:
2019-04-23T11:03:46 Welcome, you are now connected to log-streaming service.
2019-04-23T11:03:59.185 [Information] Executing 'Functions.branding-tool-app' (Reason='This function was programmatically called via the host APIs.', Id=xyz)
2019-04-23T11:04:00.793 [Information] before call
2019-04-23T11:04:00.794 [Information] Promise { <pending> }
2019-04-23T11:04:00.926 [Information] Executed 'Functions.xyz' (Succeeded, Id=xzy)
As you can see the Promise has still the status 'pending' and is not resolve in the createBlob function. What am I doing wrong here?

Answer 1

Here is the complete function for uploading localfile to blob
await uploadLocalFile(aborter, containerURL, localFilePath);
console.log(`Local file "${localFilePath}" is uploaded`);
async function uploadLocalFile(aborter, containerURL, filePath) {
filePath = path.resolve(filePath);
const fileName = path.basename(filePath);
const blockBlobURL = BlockBlobURL.fromContainerURL(containerURL, fileName);
return await uploadFileToBlockBlob(aborter, filePath, blockBlobURL);
}
For reference i am passing the complete quick start functionality.
const {
Aborter,
BlockBlobURL,
ContainerURL,
ServiceURL,
SharedKeyCredential,
StorageURL,
uploadStreamToBlockBlob,
uploadFileToBlockBlob
} = require('#azure/storage-blob');
const fs = require("fs");
const path = require("path");
if (process.env.NODE_ENV !== "production") {
require("dotenv").config();
}
const STORAGE_ACCOUNT_NAME = process.env.AZURE_STORAGE_ACCOUNT_NAME;
const ACCOUNT_ACCESS_KEY = process.env.AZURE_STORAGE_ACCOUNT_ACCESS_KEY;
const ONE_MEGABYTE = 1024 * 1024;
const FOUR_MEGABYTES = 4 * ONE_MEGABYTE;
const ONE_MINUTE = 60 * 1000;
async function showContainerNames(aborter, serviceURL) {
let response;
let marker;
do {
response = await serviceURL.listContainersSegment(aborter, marker);
marker = response.marker;
for(let container of response.containerItems) {
console.log(` - ${ container.name }`);
}
} while (marker);
}
async function uploadLocalFile(aborter, containerURL, filePath) {
filePath = path.resolve(filePath);
const fileName = path.basename(filePath);
const blockBlobURL = BlockBlobURL.fromContainerURL(containerURL, fileName);
return await uploadFileToBlockBlob(aborter, filePath, blockBlobURL);
}
async function uploadStream(aborter, containerURL, filePath) {
filePath = path.resolve(filePath);
const fileName = path.basename(filePath).replace('.md', '-stream.md');
const blockBlobURL = BlockBlobURL.fromContainerURL(containerURL, fileName);
const stream = fs.createReadStream(filePath, {
highWaterMark: FOUR_MEGABYTES,
});
const uploadOptions = {
bufferSize: FOUR_MEGABYTES,
maxBuffers: 5,
};
return await uploadStreamToBlockBlob(
aborter,
stream,
blockBlobURL,
uploadOptions.bufferSize,
uploadOptions.maxBuffers);
}
async function showBlobNames(aborter, containerURL) {
let response;
let marker;
do {
response = await containerURL.listBlobFlatSegment(aborter);
marker = response.marker;
for(let blob of response.segment.blobItems) {
console.log(` - ${ blob.name }`);
}
} while (marker);
}
async function execute() {
const containerName = "demo";
const blobName = "quickstart.txt";
const content = "hello!";
const localFilePath = "./readme.md";
const credentials = new SharedKeyCredential(STORAGE_ACCOUNT_NAME, ACCOUNT_ACCESS_KEY);
const pipeline = StorageURL.newPipeline(credentials);
const serviceURL = new ServiceURL(`https://${STORAGE_ACCOUNT_NAME}.blob.core.windows.net`, pipeline);
const containerURL = ContainerURL.fromServiceURL(serviceURL, containerName);
const blockBlobURL = BlockBlobURL.fromContainerURL(containerURL, blobName);
const aborter = Aborter.timeout(30 * ONE_MINUTE);
console.log("Containers:");
await showContainerNames(aborter, serviceURL);
await containerURL.create(aborter);
console.log(`Container: "${containerName}" is created`);
await blockBlobURL.upload(aborter, content, content.length);
console.log(`Blob "${blobName}" is uploaded`);
await uploadLocalFile(aborter, containerURL, localFilePath);
console.log(`Local file "${localFilePath}" is uploaded`);
await uploadStream(aborter, containerURL, localFilePath);
console.log(`Local file "${localFilePath}" is uploaded as a stream`);
console.log(`Blobs in "${containerName}" container:`);
await showBlobNames(aborter, containerURL);
const downloadResponse = await blockBlobURL.download(aborter, 0);
const downloadedContent = downloadResponse.readableStreamBody.read(content.length).toString();
console.log(`Downloaded blob content: "${downloadedContent}"`);
await blockBlobURL.delete(aborter)
console.log(`Block blob "${blobName}" is deleted`);
await containerURL.delete(aborter);
console.log(`Container "${containerName}" is deleted`);
}
execute().then(() => console.log("Done")).catch((e) => console.log(e));
Reference
https://github.com/Azure-Samples/azure-storage-js-v10-quickstart