SysDB and gNMI

Haylin Moore - 2024-01-20 - streaming EOS SysDB data over gNMI


Exploring Sysdb with TerminAttr and REST API

  1. Enable TerminAttr: Begin by enabling the TerminAttr daemon on your device. This can be done with the following configuration commands:
spine1#config
spine1(config)#daemon TerminAttr
spine1(config-daemon-TerminAttr)#exec /usr/bin/TerminAttr -grpcaddr 0.0.0.0:6042
spine1(config-daemon-TerminAttr)#no shutdown
spine1(config-daemon-TerminAttr)#bash

This configuration initializes the TerminAttr service, which provides a REST API to explore its data, including Sysdb.

  1. Access Sysdb via REST API: Once TerminAttr is running, use the REST API to explore Sysdb. Start by checking available paths:
bash-4.2# curl localhost:6060/rest/Sysdb
{
    "config": {
        "_ptr": "/Sysdb/sys/net/config"
    }
}

This command will return a JSON structure with various Sysdb paths, each having a _ptr reference.

  1. Browse Sysdb Paths: Use the REST API to navigate through the Sysdb paths. For example, to access network configuration data, you might use:
bash-4.2# curl localhost:6060/rest/Sysdb/sys/net/config
{
    "dnsCacheCountersUpdateInterval": 3,
    "dnsCacheSize": 4096,
    "domainList": {},
    "domainListMetadata": {
        "head": 0,
        "tail": 0
    },
    "domainName": "",
    "dscpValue": 0,
    "externalDnsProxy": false,
    "hostAddr": {},
    "hostname": "n1",
    "hostnameTimeout": 20,
    "name": "config",
    "nameServer": {
        "1.1.1.1_default": {
            "priority": 0,
            "vrfIpPair": {
                "ip": "1.1.1.1",
                "vrfName": {
                    "value": "default"
                }
            }
        }
    },
    "sourceIntf": {},
    "v6NameServer": {}
}

You will receive a JSON response with the relevant Sysdb data.

Streaming Sysdb Data Over gNMI

After identifying the desired Sysdb paths using TerminAttr and the REST API, you can proceed to stream this data over gNMI. For non-openconfig paths, use the eos_native prefix and enable it on the device.

management api gnmi
   transport grpc default
       no shutdown
   provider eos-native

If we try to get the hostname directly, we get an empty response:

bash-4.2# gnmic -a 0.0.0.0:6030 -u admin -p admin --insecure --gzip get --path "eos_native:/Sysdb/sys/net/config/hostname"
[]

This is because when pulling from Sysdb via gNMI, we need to use the closest _ptr reference, as only entire objects can be pulled. In this case, we can use the last _ptr we saw in the REST API output:

bash-4.2# gnmic -a 0.0.0.0:6030 -u admin -p admin --insecure --gzip get --path "eos_native:/Sysdb/sys/net/config" --format flat
dnsCacheCountersUpdateInterval: {}
eos_native:Sysdb/sys/net/config/dnsCacheSize: 4096
eos_native:Sysdb/sys/net/config/domainListMetadata/head: 0
eos_native:Sysdb/sys/net/config/domainListMetadata/tail: 0
eos_native:Sysdb/sys/net/config/domainName:
eos_native:Sysdb/sys/net/config/dscpValue: 0
eos_native:Sysdb/sys/net/config/externalDnsProxy: false
eos_native:Sysdb/sys/net/config/hostname: spine1
eos_native:Sysdb/sys/net/config/name: config
hostnameTimeout: {}
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