Updating Amazon SQS queues - AWS SDK for .NET

Do you want to deploy your .NET applications to AWS in just a few simple clicks? Try our new .NET CLI tooling for a simplified deployment experience! Read our blog post and submit your feedback on GitHub!

For additional information, see the section for the deployment tool in this guide.

Updating Amazon SQS queues

This example shows you how to use the AWS SDK for .NET to update an Amazon SQS queue. After some checks, the application updates the given attribute with the given value, and then shows all attributes for the queue.

If only the queue URL is included in the command-line arguments, the application simply shows all attributes for the queue.

The following sections provide snippets of this example. The complete code for the example is shown after that, and can be built and run as is.

Show queue attributes

The following snippet shows the attributes of the queue identified by the given queue URL.

The example at the end of this topic shows this snippet in use.

// // Method to show all attributes of a queue private static async Task ShowAllAttributes(IAmazonSQS sqsClient, string qUrl) { GetQueueAttributesResponse responseGetAtt = await sqsClient.GetQueueAttributesAsync(qUrl, new List<string>{ QueueAttributeName.All }); Console.WriteLine($"Queue: {qUrl}"); foreach(var att in responseGetAtt.Attributes) Console.WriteLine($"\t{att.Key}: {att.Value}"); }

Validate attribute name

The following snippet validates the name of the attribute being updated.

The example at the end of this topic shows this snippet in use.

// // Method to check the name of the attribute private static bool ValidAttribute(string attribute) { var attOk = false; var qAttNameType = typeof(QueueAttributeName); List<string> qAttNamefields = new List<string>(); foreach(var field in qAttNameType.GetFields()) qAttNamefields.Add(field.Name); foreach(var name in qAttNamefields) if(attribute == name) { attOk = true; break; } return attOk; }

Update queue attribute

The following snippet updates an attribute of the queue identified by the given queue URL.

The example at the end of this topic shows this snippet in use.

// // Method to update a queue attribute private static async Task UpdateAttribute( IAmazonSQS sqsClient, string qUrl, string attribute, string value) { await sqsClient.SetQueueAttributesAsync(qUrl, new Dictionary<string, string>{{attribute, value}}); }

Complete code

This section shows relevant references and the complete code for this example.

NuGet packages:

Programming elements:

using System; using System.Collections.Generic; using System.Threading.Tasks; using Amazon.SQS; using Amazon.SQS.Model; namespace SQSUpdateQueue { // = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = // Class to update a queue class Program { private const int MaxArgs = 3; private const int InvalidArgCount = 2; static async Task Main(string[] args) { // Parse the command line and show help if necessary var parsedArgs = CommandLine.Parse(args); if(parsedArgs.Count == 0) { PrintHelp(); return; } if((parsedArgs.Count > MaxArgs) || (parsedArgs.Count == InvalidArgCount)) CommandLine.ErrorExit("\nThe number of command-line arguments is incorrect." + "\nRun the command with no arguments to see help."); // Get the application arguments from the parsed list var qUrl = CommandLine.GetArgument(parsedArgs, null, "-q"); var attribute = CommandLine.GetArgument(parsedArgs, null, "-a"); var value = CommandLine.GetArgument(parsedArgs, null, "-v", "--value"); if(string.IsNullOrEmpty(qUrl)) CommandLine.ErrorExit("\nYou must supply at least a queue URL." + "\nRun the command with no arguments to see help."); // Create the Amazon SQS client var sqsClient = new AmazonSQSClient(); // In the case of one command-line argument, just show the attributes for the queue if(parsedArgs.Count == 1) await ShowAllAttributes(sqsClient, qUrl); // Otherwise, attempt to update the given queue attribute with the given value else { // Check to see if the attribute is valid if(ValidAttribute(attribute)) { // Perform the update and then show all the attributes of the queue await UpdateAttribute(sqsClient, qUrl, attribute, value); await ShowAllAttributes(sqsClient, qUrl); } else { Console.WriteLine($"\nThe given attribute name, {attribute}, isn't valid."); } } } // // Method to show all attributes of a queue private static async Task ShowAllAttributes(IAmazonSQS sqsClient, string qUrl) { GetQueueAttributesResponse responseGetAtt = await sqsClient.GetQueueAttributesAsync(qUrl, new List<string>{ QueueAttributeName.All }); Console.WriteLine($"Queue: {qUrl}"); foreach(var att in responseGetAtt.Attributes) Console.WriteLine($"\t{att.Key}: {att.Value}"); } // // Method to check the name of the attribute private static bool ValidAttribute(string attribute) { var attOk = false; var qAttNameType = typeof(QueueAttributeName); List<string> qAttNamefields = new List<string>(); foreach(var field in qAttNameType.GetFields()) qAttNamefields.Add(field.Name); foreach(var name in qAttNamefields) if(attribute == name) { attOk = true; break; } return attOk; } // // Method to update a queue attribute private static async Task UpdateAttribute( IAmazonSQS sqsClient, string qUrl, string attribute, string value) { await sqsClient.SetQueueAttributesAsync(qUrl, new Dictionary<string, string>{{attribute, value}}); } // // Command-line help private static void PrintHelp() { Console.WriteLine("\nUsage: SQSUpdateQueue -q queue_url [-a attribute -v value]"); Console.WriteLine(" -q: The URL of the queue you want to update."); Console.WriteLine(" -a: The name of the attribute to update."); Console.WriteLine(" -v, --value: The value to assign to the attribute."); } } // = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = // Class that represents a command line on the console or terminal. // (This is the same for all examples. When you have seen it once, you can ignore it.) static class CommandLine { // // Method to parse a command line of the form: "--key value" or "-k value". // // Parameters: // - args: The command-line arguments passed into the application by the system. // // Returns: // A Dictionary with string Keys and Values. // // If a key is found without a matching value, Dictionary.Value is set to the key // (including the dashes). // If a value is found without a matching key, Dictionary.Key is set to "--NoKeyN", // where "N" represents sequential numbers. public static Dictionary<string,string> Parse(string[] args) { var parsedArgs = new Dictionary<string,string>(); int i = 0, n = 0; while(i < args.Length) { // If the first argument in this iteration starts with a dash it's an option. if(args[i].StartsWith("-")) { var key = args[i++]; var value = key; // Check to see if there's a value that goes with this option? if((i < args.Length) && (!args[i].StartsWith("-"))) value = args[i++]; parsedArgs.Add(key, value); } // If the first argument in this iteration doesn't start with a dash, it's a value else { parsedArgs.Add("--NoKey" + n.ToString(), args[i++]); n++; } } return parsedArgs; } // // Method to get an argument from the parsed command-line arguments // // Parameters: // - parsedArgs: The Dictionary object returned from the Parse() method (shown above). // - defaultValue: The default string to return if the specified key isn't in parsedArgs. // - keys: An array of keys to look for in parsedArgs. public static string GetArgument( Dictionary<string,string> parsedArgs, string defaultReturn, params string[] keys) { string retval = null; foreach(var key in keys) if(parsedArgs.TryGetValue(key, out retval)) break; return retval ?? defaultReturn; } // // Method to exit the application with an error. public static void ErrorExit(string msg, int code=1) { Console.WriteLine("\nError"); Console.WriteLine(msg); Environment.Exit(code); } } }

Additional considerations

  • To update the RedrivePolicy attribute, you must quote the entire value and escape the quotes for the key/value pairs, as appropriate for you operating system.

    On Windows, for example, the value is constructed in a manner similar to the following:

    "{\"deadLetterTargetArn\":\"DEAD_LETTER-QUEUE-ARN\",\"maxReceiveCount\":\"10\"}"