Hello World

The following is a simple example to give you an idea of how CloudSlang is structured and can be used to ensure your environment is set up properly to run flows.

Prerequisites

This example uses the CloudSlang CLI to run a flow. See the CloudSlang CLI section for instructions on how to download and run the CLI.

Although CloudSlang files can be composed in any text editor, using a modern code editor with support for YAML syntax highlighting is recommended. See Sublime Integration for instructions on how to download, install and use the CloudSlang snippets for Sublime Text.

Code files

In a new folder, create two new CloudSlang files, hello_world.sl and print.sl, and copy the code below.

hello_world.sl

namespace: examples.hello_world

flow:
  name: hello_world
  workflow:
    - sayHi:
        do:
          print:
            - text: "'Hello, World'"

print.sl

namespace: examples.hello_world

operation:
  name: print
  inputs:
    - text
  action:
    python_script: print text
  results:
    - SUCCESS

Run

Start the CLI from the folder in which your CloudSlang files reside and enter run hello_world.sl at the cslang> prompt.

The output will look similar to this:

- sayHi
Hello, World
Flow : hello_world finished with result : SUCCESS
Execution id: 101600001, duration: 0:00:00.790

Explanation

The CLI runs the flow in the file we have passed to it, namely hello_world.sl. The flow begins with an import of the operations file, print.sl, using its namespace as the value for the imports key. Next, we enter the flow named hello_world and begin its workflow. The workflow has one task named sayHi which calls the print operation from the operations file that was imported. The flow passes the string "'Hello, World'" to the text input of the print operation. The print operation performs its action, which is a simple Python script that prints the input, and then returns a result of SUCCESS. Since the flow does not contain any more tasks the flow finishes with a result of SUCCESS.

More

For a more comprehensive walkthrough of the CloudSlang language’s features, see the New Hire Tutorial.