srl-prometheus-exporter

This repo hosts a SR Linux NDK agent that exposes a Prometheus endpoint ready to be scraped by a Prometheus Server.

It uses SRL's gnmi-server over the unix socket address to retrieve gNMI updates, it then builds the Prometheus metrics and exposes them through a configurable HTTP address.

Prerequisites:

• gNMI server unix socket is enabled
• The configured HTTP address and port are accepted by SRL CPM filters

Installation

Download the RPM from the github releases page, copy it to your SRL instance and run:

sudo rpm -i srl-prometheus-exporter_0.1.0_Linux_x86_64.rpm

Connect to your SRL instance and reload the application manager

--{ + running }--[  ]--                                                                                                                                              
A:srl1# tools system app-management application app_mgr reload

Check that the prometheus-exporter app is now running

A:srl1# show system application | grep prometheus-exporter                                                                                                           
  | prometheus-exporter | 2208 | running            |                                    | 2021-09-10T21:31:30.691Z |
--{ + running }--[  ]--     

Configuration:

The metrics exposed can be configured using SRL's CLI

--{ + running }--[ system prometheus-exporter ]--
A:srl1# info detail
    address ::
    port 8888
    network-instance mgmt
    http-path /metrics
    admin-state enable
    metric interfaces {
        state enable
        help-text "SRLinux generated metric"
    }

The predefined metric names and the corresponding gNMI paths used to build the metrics are as below:

metric name	gNMI paths
"interfaces"	"/interface/statistics"
	"/interface/ethernet/statistics"
	"/interface/queue-statistics"
	"/interface/lag/members/statistics"
"subinterfaces"	"/interface/subinterface/statistics"
"lldp"	"/system/lldp/interface/statistics"
"platform"	"/platform/control/disk/statistics"
	"/platform/control/cpu/software-interrupt"
	"/platform/control/memory"
	"/platform/linecard/forwarding-complex/buffer-memory"
"acl"	"/acl/policers/system-cpu-policer/statistics"
	"/acl/policers/policer/statistics"
	"/acl/ipv4-filter/entry/statistics"
	"/acl/ipv6-filter/entry/statistics"
	"/acl/cpm-filter/ipv4-filter/entry/statistics"
	"/acl/cpm-filter/ipv6-filter/entry/statistics"
"aaa"	"/system/aaa/server-group/server/statistics"
"network-instance-bridge-table"	"/network-instance/bridge-table/statistics"
"network-instance-icmp"	"/network-instance/icmp/statistics"
"network-instance-icmp6"	"/network-instance/icmp6/statistics"
"route-table-ipv4-unicast"	"/network-instance/route-table/ipv4-unicast/statistics"
"route-table-ipv6-unicast"	"/network-instance/route-table/ipv6-unicast/statistics"
"mpls"	"/network-instance/route-table/mpls/statistics"
"isis"	"/network-instance/protocols/isis/instance/statistics"
"bgp"	"/network-instance/protocols/bgp/group/statistics"
"udp"	"/network-instance/udp/statistics"
"tcp"	"/network-instance/tcp/statistics"

The predefined paths and metrics names can be changed at startup using a configuration file.

Custom metrics can be added at runtime using SRL's CLI/gNMI/JSON-RPC interfaces as below:

--{ + candidate shared default }--[ system prometheus-exporter ]--
A:srl1# custom-metric my_metric paths [ /network-instance/protocols/bgp/statistics ]
--{ +* candidate shared default }--[ system prometheus-exporter ]-- 
A:srl1# commit now
All changes have been committed. Leaving candidate mode.
--{ + running }--[ system prometheus-exporter ]--
A:srl1# info                                                                                                                                                      
    // snipped...
    custom-metric my_metric {
        paths [
            /network-instance/protocols/bgp/statistics
        ]
    }