I've answered this question related to Azure Webjob and Resizing a image stored as a blob and so I am trying to do the same using a Function App
Each time a new blob is uploaded, I send a a new queue message.
My function is triggered by the queue message and bind to the uploaded blob. I also have a second input binding that binds to another CloudBlobContainer to be able to upload new resized images to another blob container.
My function looks like that:
#r "System.Web"
using System.IO;
using System.Web;
using ImageResizer;
using Microsoft.Azure.WebJobs;
using Microsoft.WindowsAzure;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Blob;
private static readonly int[] Sizes = { 800, 500, 250 };
public static void Run(string filename, Stream blobStream, CloudBlobContainer container, TraceWriter log)
{
log.Verbose($"C# Queue trigger function processed: {filename}");
// Extract the filename and the file extension
var name = Path.GetFileNameWithoutExtension(filename);
var ext = Path.GetExtension(filename);
// Get the mime type to set the content type
var mimeType = MimeMapping.GetMimeMapping(filename);
foreach (var width in Sizes)
{
// Set the position of the input stream to the beginning.
blobStream.Seek(0, SeekOrigin.Begin);
// Get the output stream
var outputStream = new MemoryStream();
ResizeImage(blobStream, outputStream, width);
// Get the blob reference
CloudBlockBlob blob = container.GetBlockBlobReference($"{name}-w{width}.{ext}");
// Set the position of the output stream to the beginning.
outputStream.Seek(0, SeekOrigin.Begin);
blob.UploadFromStream(outputStream);
// Update the content type => don't know if required
blob.Properties.ContentType = mimeType;
blob.SetProperties();
}
}
private static void ResizeImage(Stream input, Stream output, int width)
{
var instructions = new Instructions
{
Width = width,
Mode = FitMode.Carve,
Scale = ScaleMode.Both
};
var imageJob = new ImageJob(input, output, instructions);
// Do not dispose the source object
imageJob.DisposeSourceObject = false;
imageJob.Build();
}
The associated function.json
file:
{
"bindings": [
{
"queueName": "newfileuploaded",
"connection": "crazytunastorageaccount_STORAGE",
"name": "filename",
"type": "queueTrigger",
"direction": "in"
},
{
"path": "input-images/{queueTrigger}",
"connection": "crazytunastorageaccount_STORAGE",
"name": "blobStream",
"type": "blob",
"direction": "in"
},
{
"name": "container",
"type": "blob",
"path": "output-images",
"connection": "crazytunastorageaccount_STORAGE",
"direction": "in"
}
],
"disabled": false
}
And the project.json
file:
{
"frameworks": {
"net46":{
"dependencies": {
"ImageResizer": "4.0.5",
"WindowsAzure.Storage": "4.3.0"
}
}
}
}
Now when I compiled the function, I always got this error:
Microsoft.Azure.WebJobs.Host: Error indexing method 'Functions.ResizeBlobImage'. Microsoft.Azure.WebJobs.Host: Can't bind Blob to type 'Microsoft.WindowsAzure.Storage.Blob.CloudBlobContainer'.
Is this type supported for the moment ?
See Question&Answers more detail:
os