Javascript

javascript expressions use to the otto Javascript VM

display-with-javascript.yaml

apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: http-check
spec:
  http:
    - name: USD
      url: https://api.frankfurter.app/latest?from=USD&to=GBP,EUR,ILS
      display:
        javascript: |
          currencyCodes = { "EUR": "€", "GBP": "£", "ILS": "₪"}
          display = ""
          for (var currency in json.rates) {
            if (display != "") {
              display += ", "
            }
            display += currency + " = " + currencyCodes[currency] + json.rates[currency] + ", "
          }
          "$1 = " + display

Troubleshooting

You can print to the console for rapid development e.g. console.log(JSON.stringify(json)), this will only be shown in the logs

Underscore

The underscore library is automatically imported so you can do the following:

display-format-with-underscore.yaml

apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: http-check
spec:
  http:
    - name: USD
      url: https://api.frankfurter.app/latest?from=USD&to=GBP,EUR,ILS
      display:
        javascript: |
          currencyCodes = { "EUR": "€", "GBP": "£", "ILS": "₪"}
          "$1 = " + _.map(json.rates, function(rate, currency) {
               return currencyCodes[currency] + rate;
          }).join(", ");