Azure: Generate Topics Programmatically

The following code invokes an Azure topics generator:

using System.Threading.Tasks;
using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.Logging;
using static System.Environment;

namespace Courier.ServiceBus.Functions
{
    public static class CourierAcceptedFn
    {
        [FunctionName(nameof(CourierAcceptedFn))]
        public static async Task Run([ServiceBusTrigger("Topic.courier-accepted", "Subscription.all-messages",
                                                        Connection = "ServiceBusConnectionKey")]string json,
                                                        ILogger log)
        {
            var request       = await nameof(CourierAcceptedFn).Update(json, "courier-accepted", log);
            var connectionKey = GetEnvironmentVariable("StorageConnectionString");

            await request.GenerateTopics(connectionKey, log);
        }
    }
}

 

Here’s the topics generator:

namespace Courier.ServiceBus
{
    internal static class TopicsCreator
    {
        public static async Task GenerateTopics(this Request request, string connectionKey, ILogger log)
        {
            await request.CreateTopic("Topic.courier-eta"               , connectionKey, log);
            await request.CreateTopic("Topic.customer-cancelled"        , connectionKey, log);
            await request.CreateTopic("Topic.courier-arrived-at-pickup" , connectionKey, log);
            await request.CreateTopic("Topic.courier-enroute-to-dropoff", connectionKey, log);
            await request.CreateTopic("Topic.courier-arrived-at-dropoff", connectionKey, log);
            await request.CreateTopic("Topic.courier-dropped-off"       , connectionKey, log);
            await request.CreateTopic("Topic.courier-arrived-at-pickup" , connectionKey, log);
        }

        static async Task CreateTopic(this Request request, string topicPrefix, string connectionKey, ILogger log)
        {
            try
            {
                var topicName = createTopicId(topicPrefix, request.RequestId);
                var result = await AzureTopic.createAsync(topicName, connectionKey);

                if (result.IsError)
                    log.LogError($"{nameof(CreateTopic)} failed:\n{result.ErrorValue}");
            }
            catch (Exception ex)
            {
                log.LogError($"{topicPrefix} failed:\n{ex.GetBaseException().Message}");
            }
        }
    }
}

 

Here’s the Azure topic CRUD operations:

namespace Courier

open System.Threading.Tasks
open Microsoft.Azure.ServiceBus.Management

module AzureTopic =

    let existsAsync(topicName:string) (connectionstring:string) : Task =

        async {

            try
                let  client = ManagementClient(connectionstring)
                let! result = client.TopicExistsAsync(topicName) |> Async.AwaitTask
                return Ok result

            with
                ex -> return Error  Async.StartAsTask

    let createAsync(topicName:string) (connectionstring:string) : Task =

        async {

            try
                let  client = ManagementClient(connectionstring)
                let! found  = client.TopicExistsAsync(topicName) |> Async.AwaitTask

                if not found then

                    let description = TopicDescription(topicName, EnablePartitioning= true)
                    do! client.CreateTopicAsync(description) |> Async.AwaitTask |> Async.Ignore
                    return Ok ()

                else
                    return Error  return Error  Async.StartAsTask

    let deleteAsync(topicName:string) (connectionstring:string) : Task =

        async {

            try
                let  client = ManagementClient(connectionstring)
                let! found  = client.TopicExistsAsync(topicName) |> Async.AwaitTask

                if found then

                    do! client.DeleteTopicAsync(topicName) |> Async.AwaitTask
                    return Ok ()

                else
                    return Error  return Error  Async.StartAsTask