Evaluating the migration of Azure Functions to Microsoft Flow – Twitter IoT Integration



Almost 18 months ago I wrote this post on integrating Twitter with Azure Functions to Tweet IoT data. A derivative of that solution has been successfully running for about the same period. Azure Functions have been bullet proof for me.

After recently implementing Microsoft Flow as detailed in my Teenager Notification Device post here I started looking at a number of the Azure Functions I have running and looked at what would be better suited to being implemented with Flow. What could I simplify by migrating to Microsoft Flow?

The IoT Twitter Function linked above was one the simpler Functions I had running that I’ve transposed and it has been running seamlessly. I chose this particular function to migrate as the functions it was performing were actions that Microsoft Flow supported. Keep in mind (see the Summary), that there isn’t a one size fits all. Flow and Functions each have their place and often work even better together.


Transposing the IoT Twitter Function App to Microsoft Flow provided me with the same outcome, however the effort to get to that outcome is considerably less. As a quick comparison I’ve compared the key steps I needed to perform with the Azure Function to enable the integration vs what it took to implement with Microsoft Flow.

Function vs Flow.PNG

That’s pretty compelling. For the Azure Function I needed to register an App with Twitter and I needed to create an Azure Function App Plan to host my Azure Function. With Microsoft Flow I just created a Flow.

To setup and configure the Azure Function I needed to set up Deployment Options to upload the Twitter PowerShell Module (this is the third-party module), and I needed to store the two credential sets associated with the Twitter Account/App. In Microsoft Flow I just chose Twitter as an Action and provided conscent to the oAuth2 challenge.

Finally for the logic of the Azure Function I had to write the script to retrieve the data, manipulate it, and then post it to Twitter. In Microsoft Flow it was simply a case of configuring the workflow logic.

Microsoft Flow

As detailed above, the logic is still the same. On a schedule, get the data from the IoT Devices via a RestAPI, manipulate/parse the response and output a Tweet with the environment info. Doing that in Flow though means selection of an action and configuring it. No code, no modules, no keys.

Below is a resultant Flow (overview) to achieve the same result as my Azure Function that I originally implemented as an Azure Function as detailed here.

MS Flow - Twitter.PNG

The schedule part is triggered hourly. Using Recurrence it is easy to set the schedule (much easier than a CRON format in Azure Functions) complete with timezone (within the advanced section). I then get the Current time to allow me to acquire the Date and Time in a format that I will use in the resulting tweet.


Next is to perform the first RestAPI call to get the data from the first of the IoT devices. Parse the JSON response to get the temperature value.


Repeat the above step for the other IoT Device located in a different environment and parse that. Formulate the Tweet using elements of information from the Flow.

Repeat and Tweet

Looking at Twitter we see a resultant Tweet from the Flow.



This is a relatively simple flow. Bare in mind I haven’t included any logic to validate what is returned or perform any conditional operations during processing. But very quickly it is possible to retrieve, manipulate and output to a different medium.

So why don’t I used Flow for everything? The recent post I mentioned at the beginning for the Teenager Notification Device that also used a Flow, also uses an Azure Function. For that use case the integration of the IoT Device with Azure IoT is via MQTT. There isn’t currently that capability in Flow. But Flow was used to initiate an Action of initiating a trigger for an Azure Function that in turn sent an MQTT message to an IoT Device. The combination of Flow with Functions provides a lot of flexibility and power.


How to use a Powershell Azure Function to Tweet IoT environment data



This blog post details how to use a Powershell Azure Function App to get information from a RestAPI and send a social media update.

The data can come from anywhere, and in the case of this example I’m getting the data from WioLink IoT Sensors. This builds upon my previous post here that details using Powershell to get environmental information and put it in Power BI.  Essentially the difference in this post is outputting the manipulated data to social media (Twitter) whilst still using a TimerTrigger Powershell Azure Function App to perform the work and leverage the “serverless” Azure Functions model.


The following are prerequisites for this solution;

Create a folder on your local machine for the Powershell Module then save the module to your local machine using the powershell command ‘Save-Module” as per below.

Save-Module -Name InvokeTwitterAPIs -Path c:\temp\twitter

Create a Function App Plan

If you don’t already have a Function App Plan create one by searching for Function App in the Azure Management Portal. Give it a Name, Select Consumption so you only pay for what you use, and select an appropriate location and Storage Account.

Create a Twitter App

Head over to http://dev.twitter.com and create a new Twitter App so you can interact with Twitter using their API. Give you Twitter App a name. Don’t worry about the URL too much or the need for the Callback URL. Select Create your Twitter Application.

Select the Keys and Access Tokens tab and take a note of the API Key and the API Secret. Select the Create my access token button.

Take a note of your Access Token and Access Token Secret. We’ll need these to interact with the Twitter API.

Create a Timer Trigger Azure Function App

Create a new TimerTrigger Azure Powershell Function. For my app I’m changing from the default of a 5 min schedule to hourly on the top of the hour. I did this after I’d already created the Function App as shown below. To update the schedule I edited the Function.json file and changed the schedule to “schedule”: “0 0 * * * *”

Give your Function App a name and select Create.

Configure Azure Function App Application Settings

In your Azure Function App select “Configure app settings”. Create new App Settings for your Twitter Account, Twitter Account AccessToken, AccessTokenSecret, APIKey and APISecret using the values from when you created your Twitter App earlier.

Deployment Credentials

If you haven’t already configured Deployment Credentials for your Azure Function Plan do that and take note of them so you can upload the Twitter Powershell module to your app in the next step.

Take note of your Deployment Username and FTP Hostname.

Upload the Twitter Powershell Module to the Azure Function App

Create a sub-directory under your Function App named bin and upload the Twitter Powershell Module using a FTP Client. I’m using WinSCP.

From the Applications Settings option start Kudu.

Traverse the folder structure to get the path do the Twitter Powershell Module and note it.

Update the code to replace the sample from the creation of the Trigger Azure Function as shown below to import the Twitter Powershell Module. Include the get-help lines for the module so we can see in the logs that the modules were imported and we can see the cmdlets they contain.

Validating our Function App Environment

Update the code to replace the sample from the creation of the Trigger Azure Function as shown below to import the Twitter Powershell Module. Include the get-help line for the module so we can see in the logs that the module was imported and we can see the cmdlets they contain. Select Save and Run.

Below is my output. I can see the output from the Twitter Module.

Function Application Script

Below is my sample script. It has no error handling etc so isn’t production ready, but gives a working example of getting data in from an API (in this case IoT sensors) and sends a tweet out to Twitter.

Viewing the Tweet

And here is the successful tweet.


This shows how easy it is to utilise Powershell and Azure Function Apps to get data and transform it for use in other ways. In this example a social media platform. The input could easily be business data from an API and the output a corporate social platform such as Yammer.

Follow Darren on Twitter @darrenjrobinson