def ensure_experiment_is_valid(experiment: Experiment):
"""
A chaos experiment consists of a method made of activities to carry
sequentially.
There are two kinds of activities:
* probe: detecting the state of a resource in your system or external to it
There are two kinds of probes: `steady` and `close`
* action: an operation to apply against your system
Usually, an experiment is made of a set of `steady` probes that ensure the
system is sound to carry further the experiment. Then, an action before
another set of of ̀close` probes to sense the state of the system
post-action.
This function raises :exc:`InvalidExperiment`, :exc:`InvalidProbe` or
:exc:`InvalidAction` depending on where it fails.
"""
logger.info("Validating the experiment's syntax")
if not experiment:
raise InvalidExperiment("an empty experiment is not an experiment")
if not experiment.get("title"):
raise InvalidExperiment("experiment requires a title")
if not experiment.get("description"):
raise InvalidExperiment("experiment requires a description")
tags = experiment.get("tags")
if tags:
if list(filter(lambda t: t == '' or not isinstance(t, str), tags)):
raise InvalidExperiment(
"experiment tags must be a non-empty string")
validate_extensions(experiment)
config = load_configuration(experiment.get("configuration", {}))
load_secrets(experiment.get("secrets", {}), config)
ensure_hypothesis_is_valid(experiment)
method = experiment.get("method")
if not method:
raise InvalidExperiment("an experiment requires a method with "
"at least one activity")
for activity in method:
ensure_activity_is_valid(activity)
# let's see if a ref is indeed found in the experiment
ref = activity.get("ref")
if ref and not lookup_activity(ref):
raise InvalidActivity("referenced activity '{r}' could not be "
"found in the experiment".format(r=ref))
rollbacks = experiment.get("rollbacks", [])
for activity in rollbacks:
ensure_activity_is_valid(activity)
warn_about_deprecated_features(experiment)
validate_controls(experiment)
logger.info("Experiment looks valid")
def test_extensions_must_have_name():
with pytest.raises(InvalidExperiment):
exp = experiments.Experiment.copy()
set_extension(exp, {"somekey": "blah"})
validate_extensions(exp)