HTTP

This check performs queries on HTTP endpoints, and HTTP Namespaces to monitor their activity.

apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: http-check
spec:
  interval: 30
  http:
    - name: http pass response 200 status code
      endpoint: https://httpbin.demo.aws.flanksource.com/status/200
      thresholdMillis: 3000
      responseCodes: [201, 200, 301]
      maxSSLExpiry: 7

Field	Description	Scheme
name*	Name of the check, must be unique within the canary	string
url*	HTTP URL	string
body	Request Body Contents	string
body	Request Body Contents	string
headers	Header fields	[]EnvVar
maxSSLExpiry	Max SSL expiry days	integer
method	HTTP Request method. Defaults to GET	string
responseCodes	Expected response codes	[]int
responseContent	Expected response content	string
templateBody	If true body will be templated	boolean
thresholdMillis	Request timeout. Defaults to 5000	integer
tlsConfig	TLS Config	TLSConfig
description	Description for the check	string
display	Expression to change the formatting of the display	Expression
icon	Icon for overwriting default icon on the dashboard	Icon
labels	Labels for check	map[string]string
metrics	Metrics to export from	[]Metrics
test	Evaluate whether a check is healthy	Expression
transform	Transform data from a check into multiple individual checks	Expression
username		EnvVar
password		EnvVar

TLS Config

Field	Description	Scheme
ca	PEM encoded certificate of the CA to verify the server certificate	EnvVar
cert	PEM encoded client certificate	EnvVar
handshakeTimeout	Timeout for SSL Handshake (defaults to 10 seconds)	integer
insecureSkipVerify	Controls whether a client verifies the server's certificate chain and host name	boolean
key	PEM encoded client private key	EnvVar

You can specify either the ca or the pair of client cert & key

Example

apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: http-check
spec:
  interval: 30
  http:
    - name: http pass response 200 status code
      url: https://httpbin.demo.aws.flanksource.com/status/200
      tlsConfig:
        ca:
          valueFrom:
            secretKeyRef:
              name: ca-cert
              key: ca.pem

Result Variables

Result variables can be used in test, display and transform expressions

Name	Description	Scheme
code	HTTP response code	int
headers	HTTP response headers	map[string]string
elapsed	HTTP Request duration	time.Duration
sslAge	Time until SSL certificate expires	time.Duration
content	HTTP Response body	string
json	If Content-Type=application/json response body converted into JSON object	JSON

The above canary (http-check.yaml) is functionally equivalent to http-check-expr.yaml below

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] and sslAge > Duration('7d')"

Authentication

Basic Authentication

http_auth.yaml
apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: http-basic-auth
spec:
  http:
    - name: "basic auth fail"
      endpoint: https://httpbin.demo.aws.flanksource.com/basic-auth/hello/world
      responseCodes: [401]
    - name: "basic auth pass"
      endpoint: https://httpbin.demo.aws.flanksource.com/basic-auth/hello/world
      responseCodes: [200]
      username:
        value: hello
      password:
        value: world

OAuth

Template Body Variables

Name	Scheme
metadata.name	string
metadata.metadata.namespace	string
metadata.labels	map[string]string
{fields from []env}	any

Variables defined in env will be available to template with the name that's configured on the spec. Eg: In the following spec, the vars my_secret_path and my_secret_var, defined in env, are available during templating.

Templating request body from env variables

http_template.yaml
apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: templated-http
spec:
  interval: 30
  http:
    - name: templated-http
      endpoint: https://webhook.site/#!/9f1392a6-718a-4ef5-a8e2-bfb55b08afca/f93d307b-0aaf-4a38-b9b3-db5daaae5657/1
      responseCodes: [200]
      templateBody: true
      envVar:
        - name: db
          valueFrom:
            secretKeyRef:
              name: db-user-pass
              key: username
      body: |
        {
          "canary": "{{.canary.name}}",
          "secret": "{{.db}}"
        }

See Escaping variables

Metrics

HTTP Check Metrics
canary_check_http_response_status{status, statusClass, url}	Counter	Response code counter for each endpoint
canary_check_http_ssl_expiry{url}	Gauge

Status class is one of 1xx, 2xx, 3xx, 4xx, 5xx

Adding custom metrics

metrics.yaml
apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: http-pass-single
spec:
  interval: 30
  http:
    - name: http-minimal-check
      url: https://httpbin.demo.aws.flanksource.com/status/200
      metrics:
        - name: httpbin_count
          type: counter
          value: "1"
          labels:
            - name: check_name
              valueExpr: check.name
            - name: code
              valueExpr: code
        - name: httpbin_2xx_duration
          type: counter
          value: elapsed.getMilliseconds()
          labels:
            - name: check_name
              valueExpr: check.name

Transforming metrics into individual checks

metrics.yaml
apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: exchange-rates
  annotations:
    trace: "true"
spec:
  schedule: "every 30 @minutes"
  http:
    - name: exchange-rates
      url: https://api.frankfurter.app/latest?from=USD&to=GBP,EUR,ILS
      transform:
        expr: |
          {
            'metrics': json.rates.keys().map(k,  {
              'name': "exchange_rate",
              'type': "gauge",
              'value': json.rates[k],
              'labels': {
                "from": json.base,
                "to": k
              }
            })
          }.toJSON()
      metrics:
        - name: exchange_rate_api
          type: histogram
          value: elapsed.getMilliseconds()