Load Settings From Configuration Files¶

It is often useful to load settings from configuration files in different parts of the workflow. The loadns() (short for “load namespace”) makes this easy:

It supports loading from JSON, YAML, TOML and Python files.
It assigns all loaded variables to a namespace, which is easier to use than a dictionary.
It can load from multiple files and merge them into a single namespace.
The step calling loadns() is automatically amended with the loaded files as inputs, unless this is disabled.

Example¶

Example source files: docs/getting_started/load_namespace/

This is just a simple example with a single configuration file and a single script that uses it. In a real-world scenario, you would typically have multiple configuration files and scripts.

Create a file plan.py with the following contents:

#!/usr/bin/env python3
from stepup.core.api import runsh, static

static("config.toml")
runsh("./print_sentence.py")

It calls a script print_sentence.py, which loads a configuration file config.toml and prints a sentence to the standard output.

Create the script print_sentence.py with the following contents:

#!/usr/bin/env python3
from stepup.core.api import loadns

config = loadns("config.toml")
print(f"I love {config.fruit} an {config.vegetable} salad.")

Finally, create the configuration file config.toml with the following contents:

fruit = "apple"
vegetable = "carrot"

Make the appropriate files executable and run the plan:

chmod +x plan.py print_sentence.py
stepup boot -n 1

You should get the following screen output:

  DIRECTOR │ Listening on /tmp/stepup-########/director (StepUp 3.0.0)
   STARTUP │ (Re)initialized boot script
  DIRECTOR │ Launched worker 0
     PHASE │ run
     START │ runpy ./plan.py
   SUCCESS │ runpy ./plan.py
     START │ runsh ./print_sentence.py
   SUCCESS │ runsh ./print_sentence.py
─────────────────────────────── Standard output ────────────────────────────────
I love apple an carrot salad.
────────────────────────────────────────────────────────────────────────────────
  DIRECTOR │ Trying to delete 0 outdated output(s)
  DIRECTOR │ Stopping workers
  DIRECTOR │ See you!

As you can see, the sentence contains elements from the configuration file.

Try the Following¶

Run the plan again with stepup boot -n 1. The steps are not executed again, as expected.
Change some fields in the configuration file and run the plan again. This time, the step print_sentence.py is executed again, now with the new values from the configuration file.