usage.rst

Usage

Make sure you have installed the library <./install> and its dependencies already (enable the cli extra).

Create a simple Python module called example.py, and paste the following contents (or download it from here <examples/example.py>):

examples/example.py

Read through the comments for an explanation of the basic features of this library.

Now, simply run the following to display the tree of alerts you just defined:

$ python -m example show

This will print out to the console:

You can also generate a PrometheusRule manifest using:

$ python -m example gen-rule \
    --name example.rules --namespace example \
    --out example_rule.yaml

The generated manifest should look like this one <examples/example_rule.yaml>. Note that only DerivedAlert instances are part of this manifest (exiting alerts should not need any additional rules, and are only referred to in the derived expr).

Use the --help option to print a help message and discover more functionalities provided by these commands.

Going Further

To see a more advanced example, have a look at the MetalK8s alert tree defined under tools/lib-alert-tree/metalk8s. An easy access is provided through a tox environment:

$ tox -e alert-tree -- show