Thursday, August 27, 2015

Setting up delegated authentication between web apps in Azure Active Directory - quirks

When setting up your Azure App ID for your web apps, it's extremely important that you follow the recommended format of "https://<your tenant name>/<your app name>"

Otherwise, delegated authentication will NOT work!!

Wednesday, August 26, 2015

Using ADAL in Javascript to enable use of Azure Active Directory from an AngularJS SPA

Check this out, apparently it came out last fall in Azure:

http://www.cloudidentity.com/blog/2014/10/28/adal-javascript-and-angularjs-deep-dive/


Enabling group membership claims in delegated tokens in Azure Active Directory

In your application manifest, add the following to the root object:

{
   ....
  "groupMembershipClaims": "All",
   ....
}


Fixing redirect loops in Azure web apps that use Azure Active Directory for authentication

We've recently been using Azure Active Directory to handle authentication for a bunch of our Line-Of-Business applications that we're moving into the cloud. Unfortunately, we've been noticing that in some circumstances, we encounter redirect loops that the browser can't break out of and I've been scratching my head over it. As it turns out, the loops had a common cause: going to a URL in the application that started with http://.

Since we're all good programmers here ;), we always want to be using best practices and enforcing secure connections anyway, but it also turned out to be the fix: adding [RequireHttps] to the top of our filters list in FilterConfig.cs solved the problem and closed a security hole at the same time.

As for the initial cause: why would anybody be using HTTP anyway ? It turns out that HTTP is the default scheme for URLs in the Azure portal when you're viewing the settings for an application and people were clicking on those links to go straight into the app.

Alex

Tuesday, August 25, 2015

Parameterizing ApplicationInsights.config

I've been working on a lot of web applications in Azure recently, and we're using Application Insights to analyze logs and instrument events in the application. Additionally, we're using MSDeploy to deploy all of our applications as we're trying to get to the point of having Continuous Delivery on-premise. Because we use multiple environments, we need to use the parameters.xml file and SetParameters files to set parameters at deployment time, meaning that we also need to parameterize the InstrumentationKey used by Application Insights to determine which instance of App Insights gets the instrumentation for which application.

This is a bit of a challenge because the XPath support for the parameters.xml file is incomplete and leaves something to be desired. At first glance, I tried to use the naive XPath expression to parameterize our InstrumentationKey:

Match="/ApplicationInsights/InstrumentationKey"

I realized that this wasn't working after checking our deployments, so after some Googling, I found the recommendation that to parameterize an *element* rather than an attribute, you need to use "/text()" in your XPath expression (which makes sense if you know enough about XPath and XQuery). So I tried it:

Match="/ApplicationInsights/InstrumentationKey/text()"

Still didn't work. Then I was stumped for a while and let things simmer.

After a couple more hours and getting frustrated, it hit me: when parameterizing another element a few weeks prior, I ran into issues because a parent element of the one that I wanted to parameterize overrode the default namespace. I checked the ApplicationInsights.config file, and sure enough, the default namespace was the non-empty namespace. I had to use a wildcard to solve the previous problem, so I tried the following:

Match="/*/InstrumentationKey/text()"

Still didn't work, much to my surprise this time. After a little bit more Googling around, I found out that this time it was because the *root* element itself used a non-empty namespace, and overrode the default. I stumbled across this response by Vishal Joshi to a comment on one of his blog posts, which included a suggestion for it using something I didn't even know you could do with XPath (and I've actually got quite a bit of experience using XPath): use the local-name query operator to match only on local name rather than fully qualified name. If you're querying a document that uses an empty default namespace, they're both the same, hence why the simple match expressions work 99% of the time. Updating my query to this:

Match="//*[local-name()='InstrumentationKey']/text()"

... worked like a charm!

Creating users in a SQL Azure database

... is not as straight forward as you would think. It has some slightly different requirements for syntax than what you'd normally use to create users in a local or on-premise SQL Server instance.

You can see the tutorial page on MSDN here.

Thursday, August 20, 2015

Logging your application with App Insights instead of Windows Azure Diagnostics

We've recently started deploying applications to Microsoft Azure. Unfortunately, we don't use Cloud Apps for our web apps, and instead use MSDeploy on the command line to enable automated deployment. Consequently, we don't have any .csdef files in which to implement Windows Azure Diagnostics (WAD).

Fortunately, there's a suitable replacement for applications in Azure App Service (rather than Cloud Services): Application Insights. Not only does this provide a TraceListener for tracing your application, but also provides a whole suite of other useful diagnostics, making this something that you should really be using anyway.  Using the links here and here, I was able to get up to speed with App Insights within an hour and a half, and implement a working solution for our application.

Wednesday, August 19, 2015

Using the Azure Key Vault: an experiment

So, I've found this article on MSDN about how to use the Azure Key Vault for storing secrets, e.g. encryption keys. Let's see how it goes.

**UPDATE** : So, apparently we won't be able to use the Key Vault because use of the key vault at this time requires that your application be used in conjunction with Azure Active Directory, which ours does not. That's unfortunate.

A really quick note about deploying SQL Server .dacpac files to SQL Azure

When you're using SqlPackage.exe to deploy a .dacpac to Azure, you must have access to the 'master' table in order for the tool to retrieve information necessary to create a diff of the database and deploy the differences during the Publish action.

For that reason, you need the 'sa' account, because simply having 'db_owner' on the Azure database is not sufficient.

Tuesday, August 18, 2015

Debugging database deployments with MSDeploy and SqlPackage

I recently had problems deploying a database to Azure, and thanks to this article, I now know why. The best part of this experience is that I've learned to debug this in a much easier manner than relying on the unhelpful error message:

*** An error occurred during deployment plan generation. Deployment cannot continue.
Failed to import target model my-database-name. Detailed message Value cannot be null.
Parameter name: conn
Value cannot be null.
Parameter name: conn

The short of it is that:

1) you need to enable a log trace with these commands for dbDacFx and SSDT:

logman create trace -n DacFxDebug -p "Microsoft-SQLServerDataTools" 0x800 -o "%LOCALAPPDATA%\DacFxDebug.etl" -ets

logman create trace -n SSDTDebug -p "Microsoft-SQLServerDataToolsVS" 0x800 -o "%LOCALAPPDATA%\SSDTDebug.etl" -ets

2) Go execute the command that's causing you grief
3) Execute the following commands to stop the logging trace:

logman stop DacFxDebug -ets

logman stop SSDTDebug -ets

4) Open 'eventvwr' in the Run dialog available from the Start Menu
5) Go to the right side 'Actions' pane, and click on 'Open Saved Log'.
6) When prompted to convert the log, click 'No'.

The logs will display under the 'Saved Logs' folder in the left hand navigation tree, and you'll be able to inspect the errors that occurred. Good luck with deployment!

Thursday, August 06, 2015

Adding extra files to your MSDeploy web package with MSBuild

I've recently started getting much more in depth with Azure. I've ported some web apps up into Azure, and now I need WebJobs. I've written the jobs, manually uploaded them into my web apps, tested them out and they work great. Now I need to ensure that the WebJobs get automatically deployed with my Web Application.

As it turns out, web jobs are just a sub folder with some naming conventions underneath the App_Data folder in your web application. Unfortunately, getting those files into that folder as part of the packaging process is a couple extra (non-obvious) steps.

Following this article on ASP.NET, I was able to add in the extra files. It took a lot more Googling than I care to admit to in order to find this article. As it turns out, you really need to pick your search terms well.