Built-In File Connector & Dynamic Connection Settings

Question

Greetings,

 

We have a need to list, read, & write files from within Azure from/to external Windows shares. I'm able to accomplish this using standard Logic Apps and built-in file connectors, however, I have quite a number of different external systems I need to access & will not know which ones until runtime. The same is also true of the from/to location in either Azure Files or Azure Blob Storage. For example, a typical operation might copy a collection of files from Azure File Storage to a directory on an external Windows file share.

 

_I have found that for a built-in file connector the external Windows share & Azure source/destination seems to be mounted internally based upon information provided to the connectors at design time, & is stored in environment variables that do not appear anywhere if I download the app content, e.g. __FILESHARESTORAGE_FileSystem-18 =

Answer 1

How can we handle multiple external file shares dynamically?

When dealing with multiple file shares in Azure Logic Apps, one way to achieve dynamic access is through parameterization. By setting up parameters for your Logic App, you can specify key connection details—such as server names, share paths, and credentials—at runtime. This enables your Logic App to connect to different shares without hardcoding each location, allowing you to adjust the settings on the fly as new shares are needed.

How can we store and manage connection information securely?

To securely store sensitive information like connection strings and access credentials, Azure Key Vault is an ideal solution. By keeping these details in Key Vault, you ensure they are encrypted and only accessible to authorized users or applications. Within your Logic App, you can configure each file connector to retrieve necessary settings from Key Vault at runtime, which keeps your connections secure and prevents hardcoded credentials in the app.

Can we dynamically retrieve connection details at runtime?

Yes! You can achieve this by setting up an API or HTTP-triggered endpoint that your Logic App can call to retrieve specific connection information. For instance, an Azure Function or other API can serve as a dynamic source for connection settings. This API can accept parameters related to the required file share and return the appropriate connection details, allowing your Logic App to connect to various shares as needed without predefining them at design time.

Is it possible to use dynamic expressions for file paths and connections?

Dynamic expressions can help you adjust certain properties at runtime, even if full dynamic connections aren’t supported. You can use expressions to populate file paths, filenames, or other properties based on Logic App inputs or variables, allowing more flexibility in specifying file destinations. Though some connector properties remain static, dynamic expressions on paths and other values offer a level of adaptability for each file operation.

What if we need a more advanced, fully dynamic connection solution?

For highly customized needs, building a custom connector could be a good fit. With a custom connector, you can create dynamic input fields and define advanced connection logic that matches your runtime requirements. This approach allows the Logic App to handle complex file transfer scenarios, offering greater flexibility in dynamically switching between various external file shares.