The health plugin provides a HTTP health check resource that can be configured to return a failure status code based on the value of a metric.
When the plugin is healthy it will return a 200 response; when unhealthy it will return a 503 response. The default state is healthy, one or more checks must fail in order for the resource to enter the failed state.
[[outputs.health]]
## Address and port to listen on.
## ex: service_address = "tcp://localhost:8080"
## service_address = "unix:///var/run/telegraf-health.sock"
# service_address = "tcp://:8080"
## The maximum duration for reading the entire request.
# read_timeout = "5s"
## The maximum duration for writing the entire response.
# write_timeout = "5s"
## Username and password to accept for HTTP basic authentication.
# basic_username = "user1"
# basic_password = "secret"
## Allowed CA certificates for client certificates.
# tls_allowed_cacerts = ["/etc/telegraf/clientca.pem"]
## TLS server certificate and private key.
# tls_cert = "/etc/telegraf/cert.pem"
# tls_key = "/etc/telegraf/key.pem"
## One or more check sub-tables should be defined, it is also recommended to
## use metric filtering to limit the metrics that flow into this output.
##
## When using the default buffer sizes, this example will fail when the
## metric buffer is half full.
##
## namepass = ["internal_write"]
## tagpass = { output = ["influxdb"] }
##
## [[outputs.health.compares]]
## field = "buffer_size"
## lt = 5000.0
##
## [[outputs.health.contains]]
## field = "buffer_size"
The compares
check is used to assert basic mathematical relationships. Use
it by choosing a field key and one or more comparisons. All comparisons must
be true on all metrics for the check to pass. If the field is not found on a
metric no comparison will be made.
The contains
check can be used to require a field key to exist on at least
one metric.