I finally found an answer to a problem that had plagued me for months! How to script, or automate, tasks in vRealize; for example, destroying a deployed blueprint. The answer was simpler than I initially thought… It turns out that the Catalog Service REST API provides all that functionality that is required to automate specific tasks such as request a Blueprint to be deployed (built), get the IP address of a VM, or destroy a deployed blueprint.
- vRealize Automation 7 REST API Request Using PowerShell
At my workplace, we use vSphere and vRealize to provide virtual machines to students for labs, assignments, and exams. Since we are using VMs in this many areas, it means that is a high overhead of managing numerous VMs. Think of having a class of 50 students, with approximately 3-6 VMs per course… resulting in large numbers of VMs to manage! I have PowerCLI scripts to perform many tasks on vSphere, yet had no solution to managing vRealize deployments or blueprints directly. That was until I read How to script a vRealize Automation 7 REST API request, by Ryan Kelly. His vRealize Automation scripts were written in BASH… However, I wanted to use PowerShell. This is primarily due to my heavy use of the PowerCLI tool to manage vSphere, which is only available on Windows PowerShell.
This post goes into detail about how to write a PowerShell script to automate connection to the vRealize Automation REST API. This post finishes with the most simple task, to list the names of any vRealize deployments that the user has access to. The post has the following prerequisites:
- An account with access to a vRealize server
- Windows PowerShell
In addition, I have started to add PowerShell scripts and modules to my vSphereScripts repository on GitHub. Like the currently available vSphere scripts, these are targeted to automate management of virtual machines.
vRealize Automation 7 REST API Request Using PowerShell
The first thing to do is open Windows PowerShell ISE or Visual Studio Code and create a new file/script. Feel free to name it whatever you want, however, it is sensible to use the
.ps1 file extension to identify it as a PowerShell script.
Connecting to a vRealize server
The first piece of information needed is the hostname of the vRealize server. For the sake of this tutorial, we will specify the following hostname:
https://vra01.corp.local/. Add a line that specifies a variable named
$vra_server that has the string of the server, for example:
This value will be used multiple times, for each API request. So it makes sense to store the information in a variable.
In order to authenticate with the vRealize server, we must have valid credentials. We could use a simple approach to get the user credentials; either 1) Hard-code them into the script, or 2) Use the
Read-Host -Prompt module. However, both of these are insecure. Instead, I recommend using the
Get-Credential module, designed specifically for handling user credentials. The following code will ask the user for a username and password and store it in a
PSCredential object. We can then extract the username and password from this object. Add the following line to your script.
Get-Credential module can be a little finicky to deal with. We will need to extract data from the
PSCredential object later in the script. Next, we must specify the tenant address for vRealize. We will, again, store this in a variable for later use.
The tenant name should be
vsphere.local, as vRealize Automation requiquires vsphere.local as the default tenant name. Ok, so far we have three key pieces of information: 1) Username, 2) Password and 3) Tenant. We must send this information, using a POST, to the REST API. We must also send this information in JSON format. So we should convert and combine the information into a single JSON object. The following code will perform this task, and store the information in a JSON object variable called
It is important to quickly summarise what just happened. The
username=$credentials.username line populates the username from
PSCredential object) into the hash table. The password population is a little trickier. The password must be sent in plaintext, not a SecureString - as stored in the
PSCrential object. The Hey, Scripting Guy! Blog provided excellent advice on how to decrypt PowerShell secure string passwords by using
GetNetworkCredential().password. Finally, copying over the tenant information is a simple reference to the
Next, we need to craft the URL to perform the POST to. The suffix of the URL is
identity/api/tokens, which can simply be added to the
$vra_server variable to get the full URL. For example, the end result will be the following URL:
This is easily achieved using string concatenation:
We now need to specify the correct headers for the API request. We need to specify what type of data we are sending, and what type of data we want to receive back. In both cases, we want to specify JSON. From my experience, the easiest and most flexible method is to use a dictionary to store multiple header variables. This is demonstrated in the following code.
To summarize, on the first line we create a new dictionary with the variable name
$header that has a key type of string and a value type of string. The second line specifies an
Accept value of
application/json so that we get JSON data back. The third line specifies a
application/json so the server knows we are sending them JSON formatted data.
Everything is now configured to actually perform authentication against the server and get a bearer token to be used in every future API request. This token is exceptionally important, and we can use it multiple times until the token is expired. It is sent with an expiry time, so you can determine how long it is valid for.
To perform authentication and get the bearer token, we can leverage the
Invoke-RestMethod module, and perform a
-Method Post. Basically, we want to post the
$data JSON object to the
$uri. In other words, we post the credentials and tenant to the URL of the REST API. We must also specify that the POST should use the
$header value we previously specified. Basically, that we are sending JSON, and want JSON back in return. It is useful to grab the response, a JSON object, and store it in a variable. The variable name we will use is
$response. The following line of code performs the POST:
This is a very simple one-line solution. However, I prefer to wrap the REST request in a
catch to check the result, so we have an idea if things go wrong. The following code snippet tries to perform the POST, and if it fails will print some useful information including the status code error, which can be very useful for debugging.
The final part, we need to extract the bearer token from the JSON we received back from the server. The
$response variable will contain three values: 1)
expires is a string value of when the token will expire, 2)
tenant is another string value of the current tenant which should be
vsphere.local, and 3)
id which is a string value of the bearer token - this is the value we want! You can easily extract the bearer token using the following code:
However, this approach has a major drawback… It is not in the correct format for subsequent REST requests. Any subsequent REST API requests will want the bearer token with a string
Bearer before the actual token. For example:
Bearer 89ry29h293930r8uru. We can leverage some string concatenation to achieve this:
$bearer_token = "Bearer " + $response.id
Nicely done if you got this far and that you could successfully get the bearer token. This is somewhat challenging, but means we are now authenticated with the vRealize server and can now perform some actually useful REST API requests using our bearer token! The full script is provided below for reference.
Listing Catalog Items (Listing Available Blueprints)
Now that we have authenticated with the vRealize server, we can perform some useful tasks. To start, we will simply list the Blueprints - these are vRealize Blueprints that are available to the authenticated user! This is a very simple example but will provide the basis on what can be achieved and guide future tasks that can be performed.
entitledCatalogItemViews is the resource needed that is provided in the Catalog Consumer REST API. The
entitledCatalogItemViews will provide a list of catalog items (blueprints) that are active, associated with a service, and that the user we have authenticated with had entitlements to consume. Basically, catalog items that we are entitled to view, and use.
The following example will continue adding to the script we started above. So you will notice that we will re-use some variables we have already defined. Start by updating the
$uri to perform a request of
Next, we will need to add the bearer token to the already defined
$header variable. We must define this additional header, or else we will get an unauthenticated error. We can simply add another dictionary entry with the key value of
Authentication, and the value set to the contents of the
Now, we will use the
Invoke-RestMethod again. However, this time we will specify a
-Method Get because we are getting information from the vRealize server.
This is very similar to the previous
Invoke-RestMethod that we used. This time we get data from the
entitledCatalogItemViews API with the specified headers - including the bearer token. We save the resultant output in the variable named
$entitled_blueprints. The information we get back is exceptionally useful and forms the basis of automated requesting of Blueprints in vRealize.
Finally, we will loop through the JSON object that was returned and simply print the name of the vRealize blueprints we have access to. This is easily achieved using the following loop. Note how we use
$entitled_blueprints.content. This structure is an array of each Blueprint available.
The script should print out something similar to the output below. I just made up the virtual machine names to provide an example.
>>> Found the following vRealize Deployments... > Ubuntu_WebServer > Ubuntu-Server-Docker > Windows-Server-2016 > CentOS-BaseInstall
From here we could perform tasks like request a blueprint to be deployed. Very nice! To get an idea of the information available I have included a full JSON object for one vRealize deployment. As you can see the information is very detailed. Moreover, the information is highly useful when
To give you some ideas of what you can do with this information here are some examples and discussion. You can select a specific Blueprint from the JSON array using the index number. For example, the Blueprint I wanted to view information about is indexed at
10, so I can use the following code to print only the JSON object for that Blueprint:
After knowing the Blueprint index, you could determine the URL needed to request the template using the following code:
There are two links provided, one for requesting a template (index
0) and one for submitting a request (index
1). I know, this is getting a little messy, but you would not usually be dynamically determining this information in a script… Rather you would query the REST API for the URL manually, then write a script to automate multiple Blueprint requests.
The best method to learn how to use the information returned by the REST API is to dynamically program and test things in PowerShell. This is one of the great benefits of using PowerShell for this type of problem. Also, there is pretty good documentation provided on the vRealize server available at the following URL (make sure to change the domain name
vra01.corp.local to the actual address of your vRealize server).
On this vRealize hosted site you can view the documentation for the vRealize REST API and all of the functions and features provided.
This post covered how to connect to a vRealize REST API using Windows PowerShell and print information about vRealize Blueprints. This was a revelation to myself and will definitely make my life easier. Please leave a comment if you have any questions or feedback. Also, please let me know if this was useful, as I might continue this post with a series about common tasks that can be automated using the vRealize REST API… using PowerShell, of course!