Pushgateway

The Pushgateway allows ephemeral and batch jobs to expose their metrics to Prometheus. Since Prometheus may not be able to scrape such a target, the targets can push their metrics to a separate instance of the Pushgateway, which then exposes these metrics to Prometheus.

from prometheus_client import CollectorRegistry, Gauge, push_to_gateway

registry = CollectorRegistry()
g = Gauge('job_last_success_unixtime', 'Last time a batch job successfully finished', registry=registry)
g.set_to_current_time()
push_to_gateway('localhost:9091', job='batchA', registry=registry)

A separate registry is used, as the default registry may contain other metrics such as those from the Process Collector.

Pushgateway functions take a grouping key.

push_to_gateway replaces metrics with the same grouping key.
pushadd_to_gateway only replaces metrics with the same name and grouping key.
delete_from_gateway deletes metrics with the given job and grouping key.
instance_ip_grouping_key returns a grouping key with the instance label set to the host’s IP address.

See the Pushgateway documentation for more information.

Handlers for authentication

If the push gateway you are connecting to is protected with HTTP Basic Auth, you can use a special handler to set the Authorization header.

from prometheus_client import CollectorRegistry, Gauge, push_to_gateway
from prometheus_client.exposition import basic_auth_handler

def my_auth_handler(url, method, timeout, headers, data):
    username = 'foobar'
    password = 'secret123'
    return basic_auth_handler(url, method, timeout, headers, data, username, password)
registry = CollectorRegistry()
g = Gauge('job_last_success_unixtime', 'Last time a batch job successfully finished', registry=registry)
g.set_to_current_time()
push_to_gateway('localhost:9091', job='batchA', registry=registry, handler=my_auth_handler)

TLS Auth is also supported when using the push gateway with a special handler.

from prometheus_client import CollectorRegistry, Gauge, push_to_gateway
from prometheus_client.exposition import tls_auth_handler


def my_auth_handler(url, method, timeout, headers, data):
    certfile = 'client-crt.pem'
    keyfile = 'client-key.pem'
    return tls_auth_handler(url, method, timeout, headers, data, certfile, keyfile)

registry = CollectorRegistry()
g = Gauge('job_last_success_unixtime', 'Last time a batch job successfully finished', registry=registry)
g.set_to_current_time()
push_to_gateway('localhost:9091', job='batchA', registry=registry, handler=my_auth_handler)