Azure Create Function App from Portal - Blob Trigger to resize Image

In this article, I am going to show, 

• what is Azure Function?
• How we can create an Azure Function from Azure Portal?
• How we can trigger our Azure Function?

I am going to explain all above through an example. I have created a Storage Account with two container

1. source
2. destination
   
   

What I am going to create in this article:

Azure Portal – Function App – BlobTriggerFunction.  I will upload an Image to source Container and will process on it and after resizing it, I will save this pic to destination Container.

Open Azure Portal: https://portal.azure.com

Login with you subscription.

Below is my Azure Storage Account:

Image 1.

Now add a new Azure Function:

Image 2.

Function App has been created. Now add + to add new function.

Image 3.

Make sure Run time version is ~1 of newly created function App.

Image 4.

Now add a trigger for this function. So here, I am going to use Blob Trigger.

Image 5.

Here we are going to upload Images in source container and will process on it and will save resized image in destination container.

Image 6.

Below is default code.

Image 7.

Now add a project.json file

Image 8.

Add below code in your project.json file. Save it. It will install NuGet packages. See log.

{
"frameworks":{
             "net46":{
                "dependencies":{
                            "ImageResizer":"4.0.5"
                               } 
                    }
             }
}

Image 9.

Now click on Integrate on Left side.

Image 10.

Set output.

Image 11.

Open run.csx file and add below code:

#r "System.Drawing" 

using ImageResizer;
using System.Drawing;
using System.Drawing.Imaging; 

public static void Run(Stream inImage, string name, string extension, Stream outImage, TraceWriter log)
{
    log.Info($"C# Blob trigger function Processed blob\n Name:{name} \n Size: {inImage.Length} Bytes"); 

    var settings= new ImageResizer.ResizeSettings
                       {
                                MaxWidth=250,
                                Format="jpg",
                                Quality=50
                     };
     ImageResizer.ImageBuilder.Current.Build(inImage,outImage,settings);   
} 

Image 12.

Now upload an image in source container from Azure portal or Storage Explorer:

Image 13.

Image uploaded in source Container:

Image 14.

Blob will trigger and will save Image in destination Container after resizing it:

Image 15.

Check your Image J

Image 16.