Serverless with Azure Functions

Demo

Add a new function

[FunctionName("ProcessFromQueue")]
public static void ProcessFromQueue(
    [ServiceBusTrigger("ProcessFile01", Connection = "ServiceBusConnection")]Message incomingMessage,
    ILogger log)
{
    log.LogInformation($"{incomingMessage.MessageId} received");
}

• Send a message with ServiceBus Explorer

{
  "FileName": "xxx.txt"
}

The ServiceBus message is injected to the function.

Deserialize the message

[FunctionName("ProcessFromQueue")]
public static void ProcessFromQueue(
    [ServiceBusTrigger("ProcessFile01", Connection = "ServiceBusConnection")]Message incomingMessage,
    ILogger log)
{
    var message = Newtonsoft.Json.JsonConvert.DeserializeObject<ProcessFileMessage>(Encoding.UTF8.GetString(incomingMessage.Body));
    log.LogInformation($"{message.FileName}");
}

Read the file

• Inject the ExecutionContext to get access to the settings
• Read the file from blob container

[FunctionName("ProcessFromQueue")]
public static void ProcessFromQueue(
    [ServiceBusTrigger("ProcessFile01", Connection = "ServiceBusConnection")]Message incomingMessage,
    ExecutionContext context,
    ILogger log)
{
    var message = Newtonsoft.Json.JsonConvert.DeserializeObject<ProcessFileMessage>(Encoding.UTF8.GetString(incomingMessage.Body));
    var storageAccountConnectionString = context.GetConfig("StorageConnection");
    var fileContent = GetFileContent(storageAccountConnectionString, message.FileName);
    log.LogInformation($"Content of {message.FileName} is {fileContent}");
}

Insert the content to a table

• Inject the Table Binding to get access to the table storage
• Insert the content

[FunctionName("ProcessFromQueue")]
public static void ProcessFromQueue(
    [ServiceBusTrigger("ProcessFile01", Connection = "ServiceBusConnection")]Message incomingMessage,
    [Table("State", Connection = "StorageConnection")] CloudTable stateTable,
    ExecutionContext context,
    ILogger log)
{
    var message = Newtonsoft.Json.JsonConvert.DeserializeObject<ProcessFileMessage>(Encoding.UTF8.GetString(incomingMessage.Body));
    var storageAccountConnectionString = context.GetConfig("StorageConnection");
    var fileContent = GetFileContent(storageAccountConnectionString, message.FileName);
    var result = stateTable.ExecuteAsync(TableOperation.Insert(new FileContentEntity(message.FileName, fileContent))).Result;
    log.LogInformation($"Content of {message.FileName} is {fileContent} and is added to state with result {result.HttpStatusCode}");
}

Trigger from blob storage

• Add a new function with a BlobTrigger

[FunctionName("ProcessFromStorage")]
public static void ProcessFromStorage(
    [BlobTrigger("files/{fileName}", Connection = "StorageConnection")] Stream file,
    string fileName,
    ILogger log)
{
    var fileContent = GetFileContent(file);
    log.LogInformation($"Content of {fileName} is {fileContent}.");
}

The blob is injected as a stream

Insert the content to a table

• Inject the Table Binding to get access to the table storage
• Insert the content

[FunctionName("ProcessFromStorage")]
public static void ProcessFromStorage(
    [BlobTrigger("files/{fileName}", Connection = "StorageConnection")] Stream file,
    [Table("State", Connection = "StorageConnection")] CloudTable stateTable,
    string fileName,
    ILogger log)
{
    var fileContent = GetFileContent(file);
    var result = stateTable.ExecuteAsync(TableOperation.Insert(new FileContentEntity(fileName, Encoding.UTF8.GetString(fileContent)))).Result;
    log.LogInformation($"Content of {fileName} is {fileContent} and is added to state with result {result.HttpStatusCode}");
}