Quickly access and manage files in Azure Functions

As you may know, there's a possibility to access files used by your Azure Function and stored by it by going to Platform Features -> App Service Editor in the portal:

It allows you to quickly browse what is accessible to your function and check whether everything is okay. Additionally you can even edit files if needed. However, what is an alternative to logging to the portal and accessing Function App by a browser? Fortunately, there's another way of doing this by using Azure Storage Explorer.

Using Storage Explorer

If you don't have Storage Explorer yet, you can easily install it from this link. Once installed, you can add a storage account used by a Function App to be able to browse its files:

Click on "Add Account"

Use storage account name and key

Enter account name and key

Once you have configured new storage account, it should be accessible from the storage account browser.

Accessing files

To access files stored by a Function App you have to choose a storage account you previously added and go to File Shares - it should display a file share names exactly as your Function App, which allows you to access files from the underlying App Service. From there you can easily access, download and modify them as you wish.

Note that this functionality is available only for "newer" Functions Apps since those created some time ago, didn't link itself to a file share.

Migrating schema and data in Azure Table Storage

Recently I faced a problem, when I had to change and adjust schema in tables stored in Azure Table Storage. The issue there was to actually automate changes so I don't have to perform them manually on each environment. This was the reason why I created a simple library called AzureTableStorageMigratorwhich helps in such tasks and eases the whole process.

The basics

The base idea was to actually create two things:

  • a simple fluent API, which will take care of chaining all tasks
  • a table which will hold all migration metadata

Current version(1.0) gives you following possibilities:

  • void Insert<T>(string tableName, T entity, bool createIfNotExists = false)
  • void DeleteTable(string tableName)
  • void CreateTable(string tableName)
  • void RenameTable<T>(string originTable, string destinationTable)
  • void Delete<T>(string tableName, T entity)
  • void Delete(string tableName, string partitionKey)
  • void Delete(string tableName, string partitionKey, string rowKey)
  • void Clear(string tableName)

and when you take a look at the example of usage:

var migrator = new Migrator();
migrator.CreateMigration(_ =>
  _.Insert("table1", new DummyEntity { PartitionKey = "pk", RowKey = DateTime.UtcNow.Ticks.ToString(), Name = "foo"});
  _.Insert("table1", new DummyEntity { PartitionKey = "pk", RowKey = DateTime.UtcNow.Ticks.ToString(), Name = "foo2"});
  _.Insert("table2", new DummyEntity { PartitionKey = "pk", RowKey = DateTime.UtcNow.Ticks.ToString(), Name = "foo"});
}, 1, "1.1", "My first migration!");

you'll see, that's pretty straightforward and self-describing. 

The way how it works is very simple - each CreateMigration() method is described using 3 different values - its id, version number and description. Each time this method is called, it'll add a new record to the versionData table to make sure, that metadata is saved and the same migration won't be run twice.

Why should I use it?

In fact it's not a matter of what you "should" do but rather what is "good" for your project. Versioning is generally a good idea, especially if you follow CI/CD pattern, where the goal is to deploy and rollback with ease. If you perform migrations by hand, you'll eventually face the situation, where rollback is either very time-consuming or almost impossible. 

It's good to remember that making your database a part of your repository(of course in terms of storing schema, not data) is considered a good practice and is one of the main parts of many modern projects.

What's next?

I published ATSM because I couldn't find a tool similar to it, which would help me version tables in Table Storage easily. For sure some new features will be added in the future, however if you find this project interesting, feel free to post an issue or a request - I'll be more than happy to discuss it.