Azure - transforming the csdef file

I adapted this idea from here: http://fabriccontroller.net/blog/posts/apply-xdt-transforms-to-your-servicedefinition-csdef-file/

Basically, we had a situation where we had an app hosted in Azure that was reliant on host headers to switch behavior. Now, host headers are defined within the .csdef as bindings - something like this:

    <Site name="Web">
        <Bindings>
          <Binding name="HttpIn" endpointName="HttpIn" />
          <Binding name="HttpIn_CO" endpointName="HttpIn_CO" hostHeader="www.xxx.co.uk" />
        </Bindings>
      </Site>
    </Sites>
    <Endpoints>
      <InputEndpoint name="HttpIn" protocol="http" port="80" />
      <InputEndpoint name="HttpIn_CO" protocol="http" port="82" />
    </Endpoints>

We also had to deploy this app in more than one country, with both sites behaving the same (with some content changes). As we were deploying the same app twice, with different headers, we had 2 options - either have n Azure projects where n is the number of countries we deploy to; or we transform the csdef to change the bindings depending on cloud configuration.

We chose the second option. The first thing I did was read the article linked at the top of this post *hint*.

The basic steps from this article are:

  1. Add the web config transform runner package to your solution
    PM> Install-Package WebConfigTransformRunner
  2. In Windows Explorer, create new .csdef files for each .cscfg file.
  3.  Manually edit the project file to add the new items as content
  4. Add a build target into the Azure project file
I followed these steps and got it all working. I was then immediately annoyed that I had two empty transform files... I had 3 .cscfg files Cloud, Cloud.AU and Local BUT I only wanted to transform Cloud.AU. So, I modified the build script to this:

<PropertyGroup>
 <ServiceDefinitionTransform>ServiceDefinition.$(TargetProfile).csdef</ServiceDefinitionTransform>
    <TransformRunnerExecutable>$(MSBuildProjectDirectory)\..\packages\WebConfigTransformRunner.1.0.0.1\Tools\WebConfigTransformRunner.exe</TransformRunnerExecutable>
  </PropertyGroup>
  <Target Name="AfterValidateServiceModel" Condition="Exists($(ServiceDefinitionTransform))">
  <Exec Command="&quot;$(TransformRunnerExecutable)&quot; @(TargetServiceDefinition) $(ServiceDefinitionTransform) @(TargetServiceDefinition)" />
  </Target>

All I did, was add a condition to the Target - "Exists($(ServiceDefinitionTransform))" which stops the target running if there's not a transform file for it.

I then deleted my 2 unused transform files and was left with one similar to this:

<?xml version="1.0" encoding="utf-8"?>
<ServiceDefinition  xmlns="http://schemas.microsoft.com/ServiceHosting/2008/10/ServiceDefinition" xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform" xdt:Locator="Condition(@name!='' and @schemaVersion!='')">
  <WebRole name="POMvc.Web" vmsize="Small" xdt:Locator="Match(name)" xdt:Transform="SetAttributes" >
    <Sites>
      <Site name="Web" xdt:Locator="Match(name)" xdt:Transform="Replace">
        <Bindings>
          <Binding name="HttpIn" endpointName="HttpIn" />
          <Binding name="HttpIn_CO" endpointName="HttpIn_CO" hostHeader="www.XXX.org.au" />
        </Bindings>
      </Site>
    </Sites>
  </WebRole>
</ServiceDefinition>

Notice that I'm also changing the VM size to reduce cost for the less used deployment :)

Comments

  1. Steve Kennaird18 November 2016 at 15:59

    Is this still working for you? I can't seem to get it to work, and am wondering if an Azure SDK update or something would have prevented this approach from working any more

    ReplyDelete
    Replies
    1. Rob Head18 November 2016 at 17:22

      As far as I'm aware it does... I'll double check on Monday and get back to you

      Delete
    2. Rob Head21 November 2016 at 08:59

      I double checked this morning and it's still working for me on SDK v2.9

      Delete
    3. Steve Kennaird21 November 2016 at 11:21

      Thanks for checking Rob, I must be doing something wrong. I'm on 2.9 too, so I'll have another look and try again

      Delete
  2. Steve Kennaird21 November 2016 at 16:01

    In case it helps anybody else, I was able to get this working with a similar approach...
    http://stevekennaird.com/different-vm-sizes-per-environment-azure-cloud-service-roles-csdef-transform

    ReplyDelete

Post a Comment

Popular posts from this blog

Trimming strings in action parameters in ASP.Net Web API

In standard MVC it's very easy to create a model binder to trim all of the strings passed into action methods. The approach I used for that was from here:  http://blogs.taiga.nl/martijn/2011/09/29/custom-model-binders-and-request-validation/ . It works well and it trims the properties of models too. The problem came when I tried to do the same thing for Web API. I added a similar StringTrimmingBinder and registered it as a service using the very non-discoverable API: var provider = new SimpleModelBinderProvider( typeof ( string ),  new StringTrimmingModelBinder()); GlobalConfiguration.Configuration.Services.Insert( typeof (ModelBinderProvider),  0,  provider); As a side note, I have no idea how you're supposed to find out how to register a model binder without opening up Bing and Googling it. Anyway, this worked great when the parameters to the action were actually strings but doesn't work with complex types as parameters. Now, I'v...
Read more

Full text search in Entity Framework 6 using command interception

Image
Background One of the main problems we encountered using Entity Framework was its lack of support for full text search. Our search function is based around a series of processors that attempt to match the incoming phrase against a set of patterns that we're expecting (10+). For example, there's one for dates and times, recent financial quarters as well as more domain specific ones. Everything is cached and so is really fast, except when it isn't: Here's the monitoring chart for our SQL DB in Azure That's a spike to 100% resource utilisation because we fall through to a phrase search as a last resort (which cannot be cached) - it's exceedingly rare but it still hurts. Before EF, the app used full text search and it was one of the casualties when the app was migrated to EF4 several years ago. The lack of full text search has been getting more and more painful as the amount of data has grown. We really needed full text search back... Command intercept...
Read more

Composing Expressions in C#

This post follows on from  Reusing predicates in Entity Framework . In my previous post I introduced the "and" extension method which allowed me to create a new entity framework safe expression from two existing expressions. Here's how we make that happen: The code is from a blogpost from Colin Meek from 2008:  InvocationExpression and LINQ to Entities . I'll just dump my version of the code here. The idea is exactly the same (even using the visitor as an immutable stack): public class InvocationExpander : ExpressionVisitor { private readonly ParameterExpression _parameter; private readonly Expression _expansion; private readonly InvocationExpander _previous; public static T Expand<T>(T expr) where T : LambdaExpression { return (T) new InvocationExpander().Visit(expr); } public InvocationExpander() { } private InvocationExpander(ParameterExpression parameter, Expression expansion, Invocati...
Read more