Developing software in the Real World

Passing secrets to your OpenWhisk action

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

Add the action to OpenWhisk with: wsk action update params params.swift -a web-export true and test:

If you use a Web Action (unauthenticated HTTP requests), then OpenWhisk will… continue reading.

Quick tip: OpenWhisk autocompletion

I've just discovered how to enable Bash autocompletion for the wsk command line tool! $ cd /usr/local/bin $ wsk sdk install bashauto This will create a file called wsk_cli_bash_completion.sh in your /usr/local/bin directory. Now, source this file within your .bash_profile or equivalent: $ echo -e "\n# OpenWhisk autocompletion\nsource ~/bin/wsk_cli_bash_completion.sh" >> ~/.bash_profile Start a new terminal window, (or source ~/.bash_profile in your current one) and you can now press the tab key after typing wsk to… continue reading.

Error handling in OpenWhisk actions

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:

If we… continue reading.

OpenWhisk web actions

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.

Serverless Swift on OpenWhisk

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.