Enable CORS Support in Cosmos DB using PowerShell

Support for Cross-Origin Resource Sharing (CORS) was recently added to Cosmos DB. If you want to enable CORS on an existing Cosmos DB account or create a new Cosmos DB account with CORS enabled it is very easy to do with Azure Resource Manager (ARM) templates or the Azure Portal.

But what if you’re wanting to find out the state of the CORS setting on an account or set it using PowerShell? Well, look no further.

The Cosmos DB PowerShell module (version 3.0.0 and above) supports creating Cosmos DB accounts with CORS enabled as well as updating and removing the CORS headers setting on an existing account. You can also retrieve the CORS setting for an existing Cosmos DB account.

Installing the CosmosDB Module

The first thing you need to do is install the CosmosDB PowerShell module from the PowerShell Gallery by running this in a PowerShell console:

This will also install the Az PowerShell modules Az.Accounts and Az.Resources modules if they are not installed on your machine. The *-CosmosDbAccount functions in the CosmosDB module are dependent on these modules.

Note: The CosmosDB PowerShell module and the Az PowerShell modules are completely cross-platform and support Linux, MacOS and Windows. Running in either Windows PowerShell (Windows) or PowerShell Core (cross-platform) is supported.

Versions of the CosmosDB PowerShell module earlier than 3.0.0.0 use the older AzureRm/AzureRm.NetCore modules and do not support the CORS setting.

Authenticating to Azure with ‘Az’

Before using the CosmosDB PowerShell module accounts functions to work with CORS settings you’ll first need to authenticate to Azure using the Az PowerShell Modules. If you’re planning on automating this process you’ll want to authenticate to Azure using a Service Principal identity.

Side note: if you’re using this module in an Azure DevOps build/release pipeline the Azure PowerShell task will take care of the Service Principal authentication process for you:

But if you’re just doing a little bit of experimentation then you can just use an interactive authentication process.

To use the interactive authentication process just enter into your PowerShell console:

then follow the instructions.

Create a Cosmos DB Account with CORS enabled

Once you have authenticated to Azure, you can use the New-CosmosDbAccount function to create a new account:

This will create a new Cosmos DB account with the name dsrcosmosdbtest in the resource group dsrcosmosdbtest-rgp in the West US location and with CORS allowed origins of https://www.fabrikam.com and https://www.contoso.com.

Important: the New-CosmosDbAccount command assumes the resource group that is specified in the ResourceGroup parameter already exists and you have contributor access to it. If the resource group doesn’t exist then you can create it using the New-AzResourceGroup function or some other method.

It will take Azure a few minutes to create the new Cosmos DB account for you.

Side note: But if you want your PowerShell automation or script to be able to get on and do other tasks in the meantime, then add the -AsJob parameter to the New-CosmosDbAccountcall. This will cause the function to immediately return and provide you a Job object that you can use to periodically query the state of the Job. More information on using PowerShell Jobs can be found here.

Be aware, you won’t be able to use the Cosmos DB account until the Job is completed.

If you look in the Azure Portal, you will find the new Cosmos DB account with the CORS allowed origin values set as per your command:

Get the CORS Allowed Origins on a Cosmos DB Account

Getting the current CORS Allowed Origins value on an account is easy too. Just run the following PowerShell command:

This will return a string containing all the CORS Allowed Origins for the Cosmos DB account dsrcosmosdbtest.

You could easily split this string into an array variable by using:

Update the CORS Allowed Origins on an existing Cosmos DB Account

To set the CORS Allowed Origins on an existing account use the Set-CosmosDbAccount function:

This will take a few minutes to update. So you can use the -AsJob parameter to run this as a Job.

Remove the CORS Allowed Origins from an existing Cosmos DB Account

You can remove the CORS Allowed Origins setting by setting using the Set-CosmosDbAccount function but passing in an empty string to the AllowedOrigin parameter:

This will take a few minutes to update as well. As always, you can use the -AsJob parameter to run this as a Job.

 

Final Words

Hopefully, you can see it is fairly simple to automate and work with the Cosmos DB CORS Allowed Origins setting using the PowerShell Cosmos DB module.

If you have any issues or queries or would like to contribute to the PowerShell Cosmos DB module, please head over to the GitHub repository.

 

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Converting a PowerShell Project to use Azure DevOps Pipelines

I wrote an article on converting my Cosmos DB PowerShell module to use a CI process in Azure DevOps over on the awesome PowerShell Magazine. Check it out here.

Disable TLS 1.0, TLS 1.1 and 3DES in Azure API Management using an ARM Template

Recently, I’ve been putting together a continuous delivery pipeline (using VSTS) for our Azure API Management service using Azure Resource Manager (ARM) templates. One of the things I needed to be able to do to secure this service properly is to disable TLS 1.0, TLS 1.1 and 3DES. This is pretty easy to do in the portal:

However, we only allow changes to be made via our continuous delivery pipeline (a good thing by the way) then I had to change the ARM template.

Side note: Disabling TLS 1.0, TLS 1.1 and 3DES is pretty important for keeping your system secure. But if you have an Azure Application Gateway in front of your API Management service, then you’ll also need to configure the Azure Application Gateway to disable TLS 1.0 and TLS 1.1. This is done in a slightly different way, but can also be done in an ARM Template (post a comment if you’re not sure how to do this and I’ll write another post).

I found the documentation for the API Management service resource here. This shows it can be done by setting the customProperties object in the ARM Template. But the documentation isn’t completely clear.

But after a little bit of trial and error I managed to figure it out and get it working. What you need to do is add the following customProperties to the properties of the API Management service resource:

This is what the complete ARM template looks like:

Side note: the template above is based off the Azure Quickstart Template for API Management.

Hopefully you find this if you’re looking for an example of how to do this and it saves you some time.

 

Managing Users & Permissions in Cosmos DB with PowerShell

If you’re just getting started with Cosmos DB, you might not have come across users and permissions in a Cosmos DB database. However, there are certain use cases where managing users and permissions are necessary. For example, if you’re wanting to be able to limit access to a particular resource (e.g. a collection, document, stored procedure) by user.

The most common usage scenario for users and permissions is if you’re implementing a Resource Token Broker type pattern, allowing client applications to directly access the Cosmos DB database.

Side note: The Cosmos DB implementation of users and permissions only provides authorization – it does not provide authentication. It would be up to your own implementation to manage the authentication. In most cases you’d use something like Azure Active Directory to provide an authentication layer.

But if you go hunting through the Azure Management Portal Cosmos DB data explorer (or Azure Storage Explorer) you won’t find any way to configure or even view users and permissions.

To manage users and permissions you need to use the Cosmos DB API directly or one of the SDKs.

But to make Cosmos DB users and permissions easier to manage from PowerShell, I created the Cosmos DB PowerShell module. This is an open source project hosted on GitHub. The Cosmos DB module allows you to manage much more than just users and permissions, but for this post I just wanted to start with these.

Requirements

This module works on PowerShell 5.x and PowerShell Core 6.0.0. It probably works on PowerShell 3 and 4, but I don’t have any more machines running this version to test on.

The Cosmos DB module does not have any dependencies, except if you call the New-Cosmos DbContext function with the ResourceGroup parameter specified as this will use the AzureRM PowerShell modules to read the Master Key for the connection directly from your Cosmos DB account. So I’d recommend installing the Azure PowerShell modules or if you’re using PowerShell 6.0, install the AzureRM.NetCore modules.

Installing the Module

The best way to install the Cosmos DB PowerShell module is from the PowerShell Gallery. To install it for only your user account execute this PowerShell command:

Install-Module -Name CosmosDB -Scope CurrentUser

Or to install it for all users on the machine (requires administrator permissions):

Install-Module -Name CosmosDB

Context Variable

Update 2018-03-06

As of Cosmos DB module v2.0.1, the connection parameter has been renamed to context and the New-CosmosDbConnection function has been renamed New-CosmosDbContext. This was to be more inline with naming adopted by the Azure PowerShell project. The old connection parameters and New-CosmosDbConnection function is still available as an alias, so older scripts won’t break. But these should be changed to use the new naming if possible as I plan to deprecate the connection version at some point in the future.

This post was updated to specify the new naming, but screenshots still show the Connection aliases.

Before you get down to the process of working with Cosmos DB resources, you’ll need to create a context variable containing the information required to connect. This requires the following information:

1. The Cosmos DB Account name
2. The Cosmos DB Database name
3. The Master Key for the account (you can have the Cosmos DB PowerShell module get this directly from your Azure account if you wish).

To create the connection variable we just use the New-CosmosDbContext:

If you do not wish to specify your master key, you can have the New-CosmosDbContext function pull your master key from the Azure Management Portal directly:

Note: This requires the AzureRM.Profile and AzureRM.Resoures module on Windows PowerShell 5.x or AzureRM.Profile.NetCore and AzureRM.Resources.NetCore on PoweShell Core 6.0.0.

Managing Users

To add a user to the Cosmos DB Database use the New-CosmosDBUser function:

New-CosmosDbUser -Context $context -Id 'daniel'

To get a list of users in the database:

Get-CosmosDbUser -Context $context

To get a specific user:

Get-CosmosDbUser -Context $context -Id 'daniel'

To remove a user (this will also remove all permissions assigned to the user):

Remove-CosmosDbUser -Context $context -Id 'daniel'

Managing Permissions

Permissions in Cosmos DB are granted to a user for a specific resource. For example, you could grant a user access to just a single document, an entire collection or to a stored procedure.

To grant a permission you need to provide four pieces of information:

1. The Id of the user to grant the permission to.
2. An Id for the permission to create. This is just string to uniquely identify the permission.
3. The permission mode to the permission: All or Read.
4. The Id of the resource to grant access to. This can be generated from one of the Get-CosmosDb*ResourcePath functions in the CosmosDB PowerShell module.

In the following example, we’ll grant the user daniel all access to the TestCollection:

Once a permission has been granted, you can use the Get-CosmosDbPermission function to retrieve the permission and with it the Resource Token that can be used to access the resource for a limited amount of time (between 10 minutes and 5 hours).

Note: as you have the Master Key already, using the Resource Token isn’t required.

For example, to retrieve all permissions for the user with Id daniel and a resource token expiration of 600 seconds:

Get-CosmosDbPermission -Context $context -UserId 'daniel' -TokenExpiry '600' |
fl *

You can as expected delete a permission by using the Remove-CosmosDbPermission function:

Remove-CosmosDbPermission -Context $context -UserId 'daniel' -Id 'AccessTestCollection'

Final Thoughts

So this is pretty much all there is to managing users and permissions using the Cosmos DB PowerShell module. This module can also be used to manage the following Cosmos DB resources:

• Attachments
• Collections
• Databases
• Documents
• Offers
• Stored procedures
• Triggers
• User Defined Functions

You can find additional documentation and examples of how to manage these resources over in the Cosmos DB PowerShell module readme file on GitHub.

Hopefully this will help you in any Cosmos DB automation tasks you might need to implement.

 

Stop, Start or Restart all Web Apps in Azure using PowerShell

Here is a short (and sometimes handy) single line of PowerShell code that can be used to restart all the Azure Web Apps in a subscription:

Note: Use this with care if you’re working with production systems because this _will_ restart these Web Apps without confirming first.

This would be a handy snippet to be able to run in the Azure Cloud Shell. It could also be adjusted to perform different actions on other types of resources.

To stop all Web Apps in a subscription use:

To start them all again:

The key part of this command is the GetEnumerator() method because most Azure Cmdlets don’t return an array of individual objects into the pipeline like typical PowerShell cmdlets. Instead returning a System.Collections.Generic.List object, which requires a slight adjustment to the code. This procedure can be used for most Azure Cmdlets to allow the results to be iterated through.

Thanks for reading.

Install Nightly Build of Azure CLI 2.0 on Windows

The Azure PowerShell cmdlets are really first class if you’re wanting to manage Azure with PowerShell. However, they don’t always support the very latest Azure components and features. For example, at the time of writing this there is no Azure PowerShell module for managing Azure Container Instances.

The solution to this is to install the Nightly Build of Azure CLI 2.0. However, on Windows it is not entirely clear the easiest way to do this. So, in this post I’ll provide a PowerShell script that will:

1. Install Python 3.x using Chocolatey
2. Use PIP (Python package manager) to install the latest nightly build packages
3. Update the Environment Path variable so that you can use Azure CLI 2.0.

Note: If you have the stable build of Azure CLI 2.0 installed using the MSI then you’ll need to configure your Environment Path variable to find the Az command that you’d like to use by default. I personally removed the stable build of Azure CLI 2.0 to make it easier.

Performing the Install

Make sure you’ve got Chocolatey installed. If you aren’t sure what Chocolatey is, it is a package management system for Windows – not unlike Apt-Get or Yum for Linux. It is free and awesome. In this process we’ll use Chocolatey to install Python for us. If you haven’t got Chocolatey installed, see this page for instructions.

Next, download and run this PowerShell script in a PowerShell Administrator Console:

You could save the content of this script into a PS1 file and then execute it like this:

It will then download and install Python, then use PIP to install the current nightly build packages. After a few minutes the installation will complete:

You can then run:

Az Login

To get started.

If you’re a bit new to Azure CLI 2.0, then another great way is to use Azure CLI Interactive:

Az Interactive

If you need to update to a newer nightly build, just run the script again and it will update your packages.

Easy as that! Now you can experiment with all the latest automation features in Azure without needing to wait for a new version of Azure CLI 2.0 or for latest Azure PowerShell cmdlets.

Edge Builds

If you want to install even more “bleeding edge” builds (built straight off the master branch on every merge to master) then you can make a small adjustment to the script above:

On line 34 change the URL of the feed from:

https://azureclinightly.blob.core.windows.net/packages

To:

https://azurecliprod.blob.core.windows.net/edge

Thanks for reading!

 

 

Sonatype Nexus Containers with Persistent Storage in Azure Container Instances

On the back of yesterdays post on running Azure Container Instance containers with persistent storage, I thought I’d try a couple of other containers with my script.

Note: I don’t actually plan on running any of these apps, I just wanted to test out the process and my scripts to identify any problems.

I tried:

• Sonatype Nexus 2 – sonatype/nexus:oss
• Sonatype Nexus 3 – sonatype/nexus3:latest
• Jenkins – jenkins/jenkins

And here are the results of my tests:

Sonatype Nexus 2

Works perfectly and the container starts up quickly (under 10 seconds):

I passed the following parameters to the script:

Note: The Nexus 2 server is only accessible on the path /nexus/.

Sonatype Nexus 3

Works perfectly but after takes at least a minute to be accessible after the container starts. But this is normal behavior for Nexus 3.

I passed the following parameters to the script:

Jenkins

Unfortunately Jenkins does not work with a persistent storage volume from an Azure Share. It seems to be trying to set the timestamp of the file that will contain the InitialAdminPassword, which is failing:

I passed the following parameters to the script:

So, this is still a little bit hit and miss, but in general Azure Container Instances look like a very promising way to run different types of services in containers without a lot of overhead. With a bit of automation, this could turn out to be a cost effective way to quickly and easily run some common services.