Category: Swift

I had a need to send a POST request with a JSON body from Swift and as I had KituraNet and SwiftyJSON already around, it proved to reasonably easy. To send a POST request using KituraNet, I wrote this code: let url = "http://httpbin.org/post". // Change to the actual URL let dataToSend = ["foo": ["bar": "baz"]] // Change to the actual data // body needs to be of type Data, use SwiftyJSON to convert let… continue reading.

Posted on 10 April 2017 in OpenWhisk, Swift

I've already written about OpenWhisk web actions and how they allow you to send a status code and HTTP headers to the client by returning a dictionary with the keys status, headers and body from your main() method: func main(args: [String:Any]) -> [String:Any] { return [ "body": "Hello world", "statusCode": 200, "headers": [ "Content-Type": "text/xml", ], ] } If this test action is in the default namespace, then we create it with wsk action update… continue reading.

Posted on 27 March 2017 in OpenWhisk, Swift

As OpenWhisk is a Functions as a Service system, it makes sense to create actions that do one thing and call other actions when they want other work done. As an example, in DrinksChooser, the choose action calls the incrementDrinkCount action which increments the count of the recommended drink in Redis. This way, choose doesn't have to know anything about Redis as that's not its job. In OpenWhisk's Swift environment, there's the Whisk.invoke() method to… continue reading.

Posted on 23 March 2017 in OpenWhisk, Swift

There is only one way to pass data into your OpenWhisk action: parameters. Your function receives a dictionary of parameters and returns one. Let's explore how you can set these parameters. Parameters passed to the action You can see this by creating this action: test.swift func main(args: [String:Any]) -> [String:Any] { return args } Add the action to OpenWhisk with: wsk action update params params.swift -a web-export true and test: $ wsk action invoke -b… continue reading.

Posted on 20 March 2017 in OpenWhisk, Swift

With a standard OpenWhisk action, we return a dictionary of the data and let OpenWhisk deal with converting it to JSON etc. OpenWhisk will also set the correct 200 status code. How do we handle an error though? It turns out that if there is a key called "error" in our returned dictionary, then all the other data is ignored and an error is sent back. To show this, consider this action: func main(args: [String:Any])… continue reading.

Posted on 13 March 2017 in OpenWhisk, Swift

The first way that you learn to call your OpenWhisk action over HTTP is a POST request that is authenticated using your API key. This key allows all sorts of write access to your account, so you never release it. If you want to access the action over HTTP without the API key, you have two choices: Web Actions or API Gateway. This article discusses how to use Web Actions as they are very useful… continue reading.

Posted on 6 March 2017 in OpenWhisk, Swift

I'm interested in serverless computing and as I write Swift, the OpenWhisk platform comes up high when you Google. This turns out to be a really good choice as OpenWhisk is Open Source so I can read the source code (and have done!). In principle, I can also run my own instance of it if I need to to for regulatory reasons, or just to avoid vendor lock-in. Commercially, the whole point of Serverless (aka… continue reading.

Posted on 27 February 2017 in OpenWhisk, Swift