Copy Data From Azure Blob Storage to AWS S3

Managed to get something working on this - it might be useful for someone else.

I decided to write an azure function that uses a HTTP request as a trigger.

These two posts helped me a lot;

How can I use NuGet packages in my Azure Functions?

Copy from Azure Blob to AWS S3 using C#

Please note my answer to the Nuget packages if you are using Azure functions 2.x.

Here is the code - you can modify the basis of this to your needs. I return a JSON Serialized object because Azure Data Factory requires this as a response from a http request sent from a pipeline;

#r "Microsoft.WindowsAzure.Storage"
#r "Newtonsoft.Json"
#r "System.Net.Http"

using System.Net;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Primitives;
using Newtonsoft.Json;
using Microsoft.WindowsAzure.Storage.Blob;
using System.Net.Http;
using Amazon.S3; 
using Amazon.S3.Model;
using Amazon.S3.Transfer;
using Amazon.S3.Util;


public static async  Task<IActionResult> Run(HttpRequest req, ILogger log)
{
    log.LogInformation("Example Function has recieved a HTTP Request");

    // get Params from query string
    string blobUri = req.Query["blobUri"];
    string bucketName = req.Query["bucketName"];

    // Validate query string
    if (String.IsNullOrEmpty(blobUri) || String.IsNullOrEmpty(bucketName)) {

        Result outcome = new Result("Invalid Parameters Passed to Function",false,"blobUri or bucketName is null or empty");
        return new BadRequestObjectResult(outcome.ConvertResultToJson());
    }

    // cast the blob to its type
    Uri blobAbsoluteUri = new Uri(blobUri);
    CloudBlockBlob blob = new CloudBlockBlob(blobAbsoluteUri);

    // Do the Copy
    bool resultBool = await CopyBlob(blob, bucketName, log);

    if (resultBool) { 
        Result outcome = new Result("Copy Completed",true,"Blob: " + blobUri + " Copied to Bucket: " + bucketName);
        return (ActionResult)new OkObjectResult(outcome.ConvertResultToJson());       
    }
    else {
        Result outcome = new Result("ERROR",false,"Copy was not successful Please review Application Logs");
        return new BadRequestObjectResult(outcome.ConvertResultToJson()); 
    }  
}

static async Task<bool> CopyBlob(CloudBlockBlob blob, string existingBucket, ILogger log) {

        var accessKey = "myAwsKey";
        var secretKey = "myAwsSecret";
        var keyName = blob.Name;

        // Make the client 
        AmazonS3Client myClient = new AmazonS3Client(accessKey, secretKey, Amazon.RegionEndpoint.EUWest1);

        // Check the Target Bucket Exists; 
        bool bucketExists = await AmazonS3Util.DoesS3BucketExistAsync (myClient,existingBucket);

        if (!bucketExists) {
            log.LogInformation("Bucket: " + existingBucket + " does not exist or is inaccessible to the application");
            return false;
        }

        // Set up the Transfer Utility
        TransferUtility fileTransferUtility = new TransferUtility(myClient);

        // Stream the file
        try {

            log.LogInformation("Starting Copy");

            using (var stream = await blob.OpenReadAsync()) {

                // Note: You need permissions to not be private on the source blob
                log.LogInformation("Streaming");

                await fileTransferUtility.UploadAsync(stream,existingBucket,keyName);

                log.LogInformation("Streaming Done");   
            }

            log.LogInformation("Copy completed");
        }
        catch (AmazonS3Exception e) {
                log.LogInformation("Error encountered on server. Message:'{0}' when writing an object", e.Message);
            }
        catch (Exception e) {
                log.LogInformation("Unknown encountered on server. Message:'{0}' when writing an object", e.Message);
                return false;
        }

        return true; 
    }

public class Result {

    public string result;
    public bool outcome;
    public string UTCtime;
    public string details; 

    public Result(string msg, bool outcomeBool, string fullMsg){
        result=msg;
        UTCtime=DateTime.Now.ToString("yyyy-MM-dd h:mm:ss tt");
        outcome=outcomeBool;
        details=fullMsg;
    }

    public string ConvertResultToJson() {
        return JsonConvert.SerializeObject(this);
    } 
}