Azure function to get all the blob storage containers in my storage account

FunctionGetBlobContainers.cs

using System; 
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks; 
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Azure.WebJobs.Host;

namespace AzBlobFuncApp
{
    public static class FunctionGetBlobContainers
    {
        /// <summary>
        /// AZ function triggered by HTTP GET to return all the blob storage containers in our system.
        /// This is going to be used by logic apps.
        /// </summary>
        /// <param name="req"></param>
        /// <param name="log"></param>
        /// <returns></returns>
        [FunctionName("GetBlobContainers")]
        public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "get", Route = null)]HttpRequestMessage req, TraceWriter log)
        {
            log.Info($"{DateTime.UtcNow} : Executing azFunc GetBlobContainers()");
              
            var azConnectionString = GetEnvironmentVariable("StorageConnectionString");

            var storageHelper = new StorageHelper(
               log,
               azConnectionString);

            // we only need names of the containers
            var containers = storageHelper.GetContainers().Select(x=>x.Name).ToList();

            return req.CreateResponse(HttpStatusCode.OK, containers);
        }

        /// <summary>
        /// retrieves the env variable from local.settings.json or from settings once deployed.
        /// </summary>
        /// <remarks>
        /// env var is stored in Values:{"something"}</remarks>
        /// <param name="name"></param>
        /// <returns></returns>
        public static string GetEnvironmentVariable(string name)
        {
            return Environment.GetEnvironmentVariable(name, EnvironmentVariableTarget.Process);
        } 
    }
}

StorageHelper.cs

using System;
using System.Collections.Generic;
using Microsoft.Azure.WebJobs.Host;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Blob;
using Microsoft.WindowsAzure.Storage.RetryPolicies;

namespace AzBlobFuncApp
{
    /// <summary>
    /// Helper class to connect to az blob storage and get containers
    /// </summary>
    public class StorageHelper
    {
        private const int RetryDeltaBackOff = 4;
        private const int RetryMaxAttemts = 5;
        private const int RetryMaxExecutionTime = 30;

        private readonly TraceWriter _logger;
        private readonly string _connectionString;

        public StorageHelper(
            TraceWriter logger,
            string sourceConnectionString)
        {
            _logger = logger;
            _connectionString = sourceConnectionString;
        }

        /// <summary>
        /// Returns all the containers in our storage account.
        /// Retries if any error occurs for resiliency.
        /// </summary>
        /// <returns></returns>
        public IEnumerable<CloudBlobContainer> GetContainers()
        {
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse(_connectionString);
            CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
            blobClient.DefaultRequestOptions.RetryPolicy = new ExponentialRetry(TimeSpan.FromSeconds(RetryDeltaBackOff), RetryMaxAttemts);
            blobClient.DefaultRequestOptions.MaximumExecutionTime = TimeSpan.FromSeconds(RetryMaxExecutionTime);

            return blobClient.ListContainers();
        }
    }
}