Health Evaluation

All checks expose a health stats of passing (Green) or failing (Red), for example the HTTP check fails if the status is 200 >= code < 299 these default behaviors can be changed using the test field:

In the example below the http check will fail if the SSL certificate expiry age is below 7 days

http-check-expr.yaml

apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: http-check-expr
spec:
  interval: 30
  http:
    - name: http pass response 200 status code
      endpoint: https://httpbin.demo.aws.flanksource.com/status/200
      test:
        expr: "code in [200,201,301] && sslAge < Duration('7d')"

Boolean

test expressions must return a bool or boolean type string ('true' or 'false')

See Cel Expressions for a function reference

Javascript and Go Templating

While test fields do support Javascript and Go Text Templates, they are not recommended for health evaluations due to their verbosity and performance.

Variables

Each check exposes different variables to use in the display expression, See the Result Variables section for each check.