Prometheus API Ruby Client
A Ruby library for reading metrics stored on a Prometheus server.
Install
gem install prometheus-api-client
Usage
Overview
require 'prometheus/api_client'
# return a client for host http://localhost:9090/api/v1/
prometheus = Prometheus::ApiClient.clientChanging server hostname
# return a client for host http://example.com:9090/api/v1/
prometheus = Prometheus::ApiClient.client(url: 'http://example.com:9090')Authentication proxy
If an authentication proxy ( e.g. oauth2 ) is used in a layer above the prometheus REST server, this client can use ssl and authentication headears.
# return a client for host https://example.com/api/v1/ using a Bearer token "TopSecret"
prometheus = Prometheus::ApiClient.client(url: 'https://example.com:443',
credentials: { token: 'TopSecret' })Low level calls
query
# send a low level get request to server
prometheus.get(
'query_range',
query: 'sum(container_cpu_usage_seconds_total' \
'{container_name="prometheus-hgv4s",job="kubernetes-nodes"})',
start: '2015-07-01T20:10:30.781Z',
end: '2015-07-02T20:10:30.781Z',
step: '120s',
)# response from server is a low level response struct including
# fields like: method, body and request_headers
# usually users will not need to use this law level calls
...
method=:get,
body="{\"status\":\"success\",
...
High level calls
query
# send a query request to server
prometheus.query(
query: 'sum(container_cpu_usage_seconds_total' \
'{container_name="prometheus-hgv4s",job="kubernetes-nodes"})',
time: '2015-07-01T20:10:30.781Z',
)# response from server:
{"resultType"=>"vector", "result"=>[{"metric"=>{}, "value"=>[1502350741.161, "6606.310387038"]}]}
query_range
# send a query_range request to server
prometheus.query_range(
query: 'sum(container_cpu_usage_seconds_total' \
'{container_name="prometheus-hgv4s",job="kubernetes-nodes"})',
start: '2015-07-01T20:10:30.781Z',
end: '2015-07-02T20:10:30.781Z',
step: '120s',
)# response from server:
{"resultType"=>"matrix",
"result"=>
[{"metric"=>
{"__name__"=>"container_cpu_usage_seconds_total",
"beta_kubernetes_io_arch"=>"amd64",
"beta_kubernetes_io_os"=>"linux",
"cpu"=>"cpu00",
"id"=>"/",
"instance"=>"example.com",
"job"=>"kubernetes-cadvisor",
"kubernetes_io_hostname"=>"example.com",
"region"=>"infra",
"zone"=>"default"},
"values"=>[[1502086230.781, "51264.830099022"],
[1502086470.781, "51277.367732154"]]},
{"metric"=>
{"__name__"=>"container_cpu_usage_seconds_total",
"beta_kubernetes_io_arch"=>"amd64",
"beta_kubernetes_io_os"=>"linux",
"cpu"=>"cpu01",
"id"=>"/",
"instance"=>"example.com",
"job"=>"kubernetes-cadvisor",
"kubernetes_io_hostname"=>"example.com",
"region"=>"infra",
"zone"=>"default"},
"values"=>[[1502086230.781, "53879.644934689"],
[1502086470.781, "53892.665282065"]]}]}
label
# send a label request to server
prometheus.label('__name__')# response from server:
["APIServiceRegistrationController_adds",
"APIServiceRegistrationController_depth",
...
targets
# send a targets request to server
prometheus.targets()# response from server:
{"activeTargets"=>
[{"discoveredLabels"=>
{"__address__"=>"10.35.19.248:8443",
"__meta_kubernetes_endpoint_port_name"=>"https",
"__meta_kubernetes_endpoint_port_protocol"=>"TCP",
"__meta_kubernetes_endpoint_ready"=>"true",
"__meta_kubernetes_endpoints_name"=>"kubernetes",
"__meta_kubernetes_namespace"=>"default",
"__meta_kubernetes_service_label_component"=>"apiserver",
"__meta_kubernetes_service_label_provider"=>"kubernetes",
"__meta_kubernetes_service_name"=>"kubernetes",
"__metrics_path__"=>"/metrics",
"__scheme__"=>"https",
"job"=>"kubernetes-apiservers"},
"labels"=>{"instance"=>"10.35.19.248:8443", "job"=>"kubernetes-apiservers"},
"scrapeUrl"=>"https://10.35.19.248:8443/metrics",
"lastError"=>"",
"lastScrape"=>"2017-08-10T07:35:40.919376413Z",
"health"=>"up"},
...
Tests
Install necessary development gems with bundle install and run tests with
rspec:
rake