Monitor Configuration

Monitor configurations define how Stylus tests your infrastructure components. Each monitor consists of a test script that runs on a schedule and reports the status back to Stylus.

Standard Monitor

A standard monitor consists of a single test for a single host.

test:
  # (optional) The internal ID to use for this test. If omitted, the ID is inferred from the monitor directory's name.
  id: foo
  # How often the test is run. The interval restarts from the last success or failure of the test.
  interval: 60s
  # How long the script will be given to run before it is killed.
  timeout: 30s
  # The test command to run, relative to the monitor directory. The PATH is not used and the file must be
  # directly executable.
  command: test.sh

Logging

Output from the test's standard output and standard error streams are captured and available from the logging endpoint.

Monitor States

The state of a monitor is determined by the return value of the test script.

• Blank: A test that has not run or completed yet
• Yellow: A test that has timed out
• Red: Tests that fail by returning a value other than zero
• Green: Tests that return zero (success)

Group Monitors

A group may be configured such that a single script may update states for multiple monitors. See Advanced Configuration for examples of configuring such a group monitor.

Metadata

Tests scripts may also set metadata associated with the run. More information on this is available in Advanced Configuration.

Testing Your Configurations

Since monitor scripts with metadata can be tricky to get right, Stylus includes a stylus test command that lets you develop your test script interactively. The output shows your script's stdout and stderr, plus the parsed monitor state as JSON, and the final rendered CSS.