Steve Spencer's Blog

I’ve wanted to use Azure Machine Learning for a while but didn’t know where to start. Microsoft have released some gallery applications for Azure ML to take away some of the complexity and make it easy for developers to use the service. One item in the gallery that will be useful is Project Oxford. Project Oxford offers a number of features and the one I am going to talk about here is the Face API.

With the Face API you can train Azure ML with pictures of a number of people and then use the matching api to see whether any of the trained people appear in the image.

This is easy to setup and there is a good tutorial here: http://www.projectoxford.ai/doc/face/How-To/identifyperson

Firstly you will need to sign up and get a subscription key http://www.projectoxford.ai/doc/general/subscription-key-mgmt

Login to Azure portal with an Azure subscription, The link should open market place. Scroll down to find Face APIs and then click through to the purchase button and purchase. This api is currently free.

Your face api service will now be created. Once complete you need to extract the keys for use in your app. Click on your face api service then click the Manage Button

Click on show to view your key and copy it into your application

Download the face api from https://www.projectoxford.ai/sdk unzip and add to your project, then add a reference in your application.

Follow the code here: http://www.projectoxford.ai/doc/face/How-To/identifyperson

Be aware that when this is run you may get a bad request error (I used fiddler to see the error) when creating a Person Group. This seems to be due to case sensitivity and when I made the parameters lower case it worked! The sample code above is mixed case but the service seems to want all lowercase. Details of the error messages can be found here: https://dev.projectoxford.ai/docs/services/54d85c1d5eefd00dc474a0ef/operations/54f0387249c3f70a50e79b84 The body of the response contains the exact details of the error.

There are limitations on file size so I ended up editing mine down to below 4MB

Once trained you can detect multiple people in one photo graph and will identify those that it knows

I've trained it with a number of people especially as my daughter was identified as her mum :-)

Now I've added her into the training files she is not mistaken.

You might need to play around with the training files especially to take into account hats and glasses.

Enjoy

Last month Microsoft announced the Azure App Service (http://azure.microsoft.com/blog/2015/03/24/announcing-azure-app-service/). The App Service incorporates Web (sites) Apps and Mobile apps and introduces two new services: API Apps and Logic Apps.

API Apps allows you to build small RESTful services that can be combined together with Web, Mobile and/or Logic apps to build your application.

There is new tooling for Visual Studio (http://blogs.msdn.com/b/visualstudio/archive/2015/03/24/introducing-the-azure-api-apps-tools-for-visual-studio-2013.aspx) to help you build API apps, as well as providing the ability to debug your API App when it is deployed in Azure (http://azure.microsoft.com/en-us/documentation/articles/app-service-dotnet-remotely-debug-api-app/).

API Apps are documented using Swagger (http://swagger.io/) and there is a UI in the portal to allow you to run the app with sample data. To access the Swagger UI click the API App URL in the portal and add \swagger to the end. Click on the API method you are interested in and then click the Action button (POST in my example below).

This expands out to allow you to exercise the API.

An example API is documented here: https://azure.microsoft.com/en-us/documentation/articles/app-service-dotnet-create-api-app/

There is also a market place for API Apps which include API connectors for Office 365, Service Bus, OneDrive, Drop Box and various others. You need to install them as API apps before they can be used in other apps. All authentication to the services is done in the API app creation process and this therefore makes it easier to wire them together as the authentication is handled for you. Connectors can be used to trigger Logic Apps and also as Actions. Details of this along with the list of available connectors is here (http://azure.microsoft.com/en-us/documentation/articles/app-service-logic-use-biztalk-connectors/)

I'm going to blog in more detail about logic apps later, but for now here are a couple of tips for API Apps:

1. In order to enable swagger and to ensure that your APIs that return data are documented correctly there is some additional code that needs to be added. This is documented here: http://blogs.msdn.com/b/hosamshobak/archive/2015/03/31/logic-app-with-simple-api-app-with-inputs-and-outputs.aspx
2. When you create an API app, especially if you created it from the market place (e.g. Azure Storage Blob Connector, Service Bus Connector etc) you are asked for configuration at the time of creation. Once it is created, it is not obvious where to find the configuration. In the new Azure Portal, Browse to API Apps and click on the one you want to reconfigure. In the Essentials panel that appears click on the API app host link. Click the settings Icon followed by Application Settings. Scroll down and any settings for the API App will be visible and can be changed. This is useful if you need to remember which service bus topic and subscription are configured for example.

If you are unaware, older versions of the Azure Storage API will be turned off in December 2015. This means that any of your applications that use these older versions will stop working. If you are accessing the Storage API through an SDK then you most likely just need to rebuild with a newer supported version. If you are accessing the REST API directly then you will need to ensure that the code changes to support the newer API versions.

Full details of the changes can be found at: http://azure.microsoft.com/blog/2014/08/04/microsoft-azure-storage-service-version-removal/

When using configuration in Microsoft Azure websites, ensure that you put configuration that you are likely to change often in AppSettings. This allows you to make configuration changes in the Management portal of Azure rather than having to edit the web.config file directly. An example of where you might like to do this include settings that allow you to disable site features temporarily such as during an upgrade or routine maintenance.

App settings in the web config file are names/value pairs and are accessed as follows:

System.Configuration.ConfigurationManager.AppSettings["StevesSetting"]

Which can be seen in the web.config as follows:

<configuration>
  .
  <appSettings>
      <add key="StevesSetting" value="Webconfig setting" />
  </appSettings>
  .
</configuration>

In order to manage this configuration in the portal you need to navigate to your website and click the configure tab (in the old portal)

and scroll down to app settings, then add in the setting you wish to change

Or in the old portal navigate to the website and click settings then applications settings and scroll down to the app settings section

Recently I’ve been looking at using traffic manager to front up websites hosted in Azure Websites. I needed to setup a custom domain name instead of using mydomain.trafficmanager.net.

In order to use Traffic Manager with an Azure website the website needs to be setup using a Standard Hosting Plan.

Each website you want to be included in the traffic manager routing will need to be added as an endpoint in the traffic manager portal.

Once you have this setup you will need to add the DNS CNAME record for your domain. This needs to be configured at your Domain provider. You set the CNAME to point to mydomain.trafficmanager.net

In order for the traffic to be routed to your Azure hosted website(s), each website setup as an endpoint in traffic manager will need to have your mapped domain e.g. www.mydomain.com  configured. This is done under settings->Custom Domains and SSL in the new portal and under the configure tab –> manage domains (or click the Manage Domains button)

If you don’t add this then you will see this 404 error page whenever you try to navigate to the site through the traffic manager custom domain name:

I’ve been setting up one of our services as the backend service for Azure API management. Part of this process we have mapped DNS to point to the service. As the service is hosted in Azure Websites there are now two urls that exist which can be used to access the service. I wanted to stop a user from accessing the site using the azurewebsites.net url and only access it via the mapped domain. This is easy to achieve and can be configured in the web.config file of the service.

In the <system.webServer> section add the following configuration

<rewrite>
    <rules>
        <rule name="Block traffic to the raw azurewebsites url"  patternSyntax="Wildcard" stopProcessing="true">
          <match url="*" />
          <conditions>
            <add input="{HTTP_HOST}" pattern="*azurewebsites.net*" />
          </conditions>
          <action type="CustomResponse" statusCode="403" statusReason="Forbidden"
          statusDescription="Site is not accessible" />
        </rule>
    </rules>
</rewrite>

Now if I try and access my site through the azurewebsites.net url, I get a 403 error, but accessing through the mapped domain is fine.

Yesterday Scott Guthrie announced a number of enhancements to Microsoft Azure. One of the enhancements is the General Availability of Azure Media Services Live Media Streaming. This gives us the ability to stream live events on a service that has already been used to deliver big events such as the 2014 Sochi Winter Olympics and the 2014 FIFA World Cup.

I’ve look at this for a couple of our projects and found it relatively fast and easy to set up a live media event even from my laptop using its built in camera. There’s a good blob post that walks you through the process of setting up the Live Streaming service. I used this post and was quickly streaming both audio and video from my laptop.

The main piece of software that you need to install is a Video/Audio Encode the supports Smooth Streaming or RTMP. I used the WireCast encoder as specified in the post. You can try out the encoder for 2 weeks as long as you don’t mind seeing the Wirecast Logo on your video (which is removed if you buy a license). Media services pricing can be found here

The Media Services team have provided a MPEG-DASH player to help you test your live streams.

It appears that once you have created a stream that is is still accessible on demand after the event has completed.Also there is around a 20s delay when you receive the stream on your player.

One of the conundrums we have with deploying sites to test means that there is often a lot of configuration that is needed on a test site that is different to a live site. There is also the time and risk of deploying a new instance into the production sites once testing has completed.

Azure websites has introduced deployments slots which allows you to have multiple deployments and swap between them in a similar way you could do with the production and staging slots in cloud services. Websites has the added advantage that you can have more than two slots and you can call them whatever you want.

One approach we are looking at to ensure consistency with what is deployed is to configure up a number of slots on the website for a variety of uses e.g. Production, Staging, UAT. The issue with having multiple slots is that there are often sets of configurations that are required to ensure that each slot will work with the correct backend. By default all configuration stored in the appsettings in web.config will move with the slot. Details of the exact configuration settings that move with the deployment can be found here (http://azure.microsoft.com/en-gb/documentation/articles/web-sites-staged-publishing/)

For example, in my web.config file I have the following setting

<appSettings>

<add key="about" value="This is the web.config text" />

</appSettings>

This setting can be overridden in the Azure portal(s) and these by default will follow the deployment and not stay with the slot.

So in this example the "about" config will be set to "This is Now the Staging slot" and when the staging slot is swapped to be production, the new production configuration will also be "This is Now the Staging slot"

This is not necessarily what you want on production. Websites has a feature, that is currently unsupported by the management portal(s), which allows specific configuration items to become sticky i.e. they stay with the slot. There is a powershell cmdlet which allows individual appsettings to be marked as sticky and remain with the slot regardless of the deployment that is in the slot and they will also remain in the slot when the slots are swapped.

This can be set for both Appsettings and connection strings by running the following commands

Set-AzureWebsite -Name somesite -SlotStickyAppSettingNames @("about", "another_config_key")

Set-AzureWebsite -Name somesite -SlotStickyConnectionStringNames @("a_connection_string", "some_other_connectionstring")

After running the commands the example above will still have the configuration setting above, but once the deployment is swapped from the staging slot to production the configuration will remain on the staging slot.

This approach should now allow us to deploy to a UAT slot with UAT configuration and allow the customer to test, when they are happy we can move the same deployment that has just been tested to the staging slot with production configuration and be tested in isolation to live to ensure that it works. When you are happy that the staging slot is working this can then be swapped out to production.

For a more detailed introduction to slots and configuration see:

http://azure.microsoft.com/en-gb/documentation/articles/web-sites-staged-publishing/

http://blog.amitapple.com/post/2014/11/azure-websites-slots/#.VG22ik1yaAg

When an Azure Website is created and is in production it will most likely be running in a Standard or Basic configuration. These are both sets of Virtual Machines and can be shared across your websites. In the old portal you could only scale the group of websites together but the new Azure Management portal now allows you to move your websites on to different virtual machines so that if one site is more heavily loaded than others it can be scaled out separately if required. The set of virtual machines is known as a Web Hosting Plan. If you want to move one or more of your websites to a different set of virtual machines then you will need to create a new web hosting plan for this.

In the new portal click on “Browse” in the left hand bar

This brings up the Browse Menu.

Select “Web hosting plans”

You can see that I only have 1 web hosting plan and it is currently hosting two websites. I would like to move them onto separate virtual machines so that I can scale them out independently.

To do this I need to navigate to the web site I wish to move.

The top menu needs to be expanded by clicking the 3 dots on the right of the menu bar. this then displays the web hosting plan button.

Clicking this displays the web hosting plan associated with this web site

Clicking on the new hosting plan option allows you to create a new plan

I’ve selected a standard small instance to host my website.

After clicking OK the new hosting plan will be created and the website moved to it. After a short while you should see that the hosting plan has changed in this website as well.

Note: you now have two hosting plans both of which will be a separate billing entity. I am also led to believe that if you move everything off of a hosting plan you will still be charged for it.Hosting plans can be deleted once all the websites have been moved off of it. This is done in the Web hosting plan page. right click on the plan you want to delete and select the Delete option

1. Use public on the main program class.In order for web jobs to initialise correctly the main class that contains the web jobs needs to be made public. Once this has been added the individual jobs can then be read and should be visible in the output when running locally.

2. In order to store and view the invocation details for each web job you need to configure AzureWebJobsDashboard in the configure tab of the website you have deployed the web job to. Even if you have configured this in your app.config file.

If this is not configured in the website then you will receive the following error when you try and view the web jobs dashboard

3. Debug using Visual Studio. Once of the nice features of the web jobs SDK is the ability to run and debug the web job locally in Visual Studio. Following the Getting Started guide, you create a console application which you can debug in Visual Studio before deploying it to Azure

4. User TextWriter for debugging. The Azure Web Jobs SDK (see the logging section) provides a mechanism to log out information that can be viewed through the Azure Web jobs dashboard. By adding a TextWriter as an input parameter to your web job method, you can use WriteLine to then output information you wish to log.

5. Make your Blob Triggers more efficient by triggering them using BlobOutput. The mechanism that the BlobInput trigger uses has a 10-20 minute lag before the trigger can fire, but each time BlobOutput is used it triggers a rescan for Blob input.

“There is an optimization where any blob written via a [BlobOutput] (as opposed to being written by some external source) will optimistically check for any matching [BlobInputs],” See How does [BlobInput] work?. Storage Queues and Service Bus topics and Queues are generally processed within seconds so if you can use a queue to trigger a BlobOutput then use this to trigger any subsequent BlobInputs