Skip to content

Listen

Description#

gnmic can be used in a "dial-out telemetry" mode by means of the listen command. In the dial-out mode:

  • a network element is configured with the telemetry paths
  • a network element initiates a connection towards the server/collector (gnmic acts as a server in that case)

Info

Currently gnmic only implements the dial-out support for Nokia1 SR OS 20.5.r1+ routers.

Usage#

gnmic listen [global flags] [local flags]

Flags#

address#

The address flag [-a | --address] tells gnmic which address to bind an internal server to in an address:port format, e.g.: 0.0.0.0:57400.

tls-cert#

Path to the TLS certificate can be supplied with --tls-cert flag.

tls-key#

Path to the private key can be supplied with --tls-key flag.

max-concurrent-streams#

To limit the maximum number of concurrent HTTP2 streams use the --max-concurrent-streams flag, the default value is 256.

prometheus-address#

The prometheus-address flag [--prometheus-address] allows starting a prometheus server that can be scraped by a prometheus client. It exposes metrics like memory, CPU and file descriptor usage.

Examples#

TLS disabled server#

To start gnmic as a server listening on all interfaces without TLS support is as simple as:

gnmic listen -a 0.0.0.0:57400
SR OS configuration for non TLS dialout connections 
/configure system telemetry destination-group "dialout" allow-unsecure-connection
/configure system telemetry destination-group "dialout" destination 10.2.0.99 port 57400 router-instance "management"
/configure system telemetry persistent-subscriptions { }
/configure system telemetry persistent-subscriptions subscription "dialout" admin-state enable
/configure system telemetry persistent-subscriptions subscription "dialout" sensor-group "port_stats"
/configure system telemetry persistent-subscriptions subscription "dialout" mode sample
/configure system telemetry persistent-subscriptions subscription "dialout" sample-interval 1000
/configure system telemetry persistent-subscriptions subscription "dialout" destination-group "dialout"
/configure system telemetry persistent-subscriptions subscription "dialout" encoding bytes
/configure system telemetry sensor-groups { }
/configure system telemetry sensor-groups { sensor-group "port_stats" }
/configure system telemetry sensor-groups { sensor-group "port_stats" path "/state/port[port-id=1/1/c1/1]/statistics/in-octets" }

TLS enabled server#

By using tls-cert and tls-key flags it is possible to run gnmic with TLS.

gnmic listen -a 0.0.0.0:57400 --tls-cert gnmic.pem --tls-key gnmic-key.pem
SR OS configuration for a TLS enabled dialout connections

The configuration below does not utilise router-side certificates and uses the certificate provided by the server (gnmic). The router will also not verify the certificate. 

/configure system telemetry destination-group "dialout" tls-client-profile "client-tls"
/configure system telemetry destination-group "dialout" destination 10.2.0.99 port 57400 router-instance "management"
/configure system telemetry persistent-subscriptions { }
/configure system telemetry persistent-subscriptions subscription "dialout" admin-state enable
/configure system telemetry persistent-subscriptions subscription "dialout" sensor-group "port_stats"
/configure system telemetry persistent-subscriptions subscription "dialout" mode sample
/configure system telemetry persistent-subscriptions subscription "dialout" sample-interval 1000
/configure system telemetry persistent-subscriptions subscription "dialout" destination-group "dialout"
/configure system telemetry persistent-subscriptions subscription "dialout" encoding bytes
/configure system telemetry sensor-groups { }
/configure system telemetry sensor-groups { sensor-group "port_stats" }
/configure system telemetry sensor-groups { sensor-group "port_stats" path "/state/port[port-id=1/1/c1/1]/statistics/in-octets" }

/configure system security tls client-cipher-list "client-ciphers" { }
/configure system security tls client-cipher-list "client-ciphers" cipher 1 name tls-rsa-with-aes128-cbc-sha
/configure system security tls client-cipher-list "client-ciphers" cipher 2 name tls-rsa-with-aes128-cbc-sha256
/configure system security tls client-cipher-list "client-ciphers" cipher 3 name tls-rsa-with-aes256-cbc-sha
/configure system security tls client-cipher-list "client-ciphers" cipher 4 name tls-rsa-with-aes256-cbc-sha256

/configure system security tls client-tls-profile "client-tls" admin-state enable
/configure system security tls client-tls-profile "client-tls" cipher-list "client-ciphers"

  1. Nokia dial-out proto definition can be found in karimra/sros-dialout ↩