telemetry_collector

Automatically build telemetry collector with Telegraf, Influxdb, and Grafana, the example of sensor paths is using the native yang model and OpenConfig yang model of NX-OS as an example. build.sh script will create self-signed certificates for TLS transport. Using docker images of Telegraf, Influxdb, and Grafana to create containers with docker-compose. tested with telegraf >= 1.12.1, influxdb >= 2.0 and grafana>=8.1.

NOTE:

This project has upgraded the Influxdb to 2.0 which is not supported by Chronograf anymore, the dashboard is changed to Grafana with a new set of sensor paths. original code is moved to branch chronograf_influxdb_1_x

Screenshoot

Requirements:

docker-ce, OpenSSL, docker-compose, any Linux distribution, see Known Issues if trying it on MacOS

How to use

To quickly start, set environment variables GNMI_USER and GNMI_PASSWORD, this user needs to be configured on nxos with a network-operator role at least, then use sudo ./build.sh start to start the containers:
```
export GNMI_USER=telemetry
export GNMI_PASSWORD=SuperSecretPassword
./build.sh start
```
```
2020-07-30T22:49:02--LOG--influxdb database folder does not exist, creating one
2020-07-30T22:49:02--LOG--change permission of config and data folder of influxdb
2020-07-30T22:49:02--LOG--generating self-signed certificates for telegraf plugins
2020-07-30T22:49:02--LOG--telegraf certificate does not exist, generating
2020-07-30T22:49:02--LOG--gernerating private key for CN telegraf
...<ommited>
```
By default, telegraf listens on tcp:57000 for gRPC dial-out, if you want to modify the port, change the config file etc/telegraf/telegraf.conf.example in the project folder

gnmi dial-in is also enabled by default, modify the switches in build.sh with mgmt address and grpc port:
```
# swtiches accept gNMI dial-in
switches=( "172.25.74.70:50051" "172.25.74.61:50051" )
```
When first starting the service, the script will check if certificates are generated, if not, it will create them for mdt and gnmi plugins to validate for 10 years. use http://<ip_address_of_host>:3000 to open Grafana gui. login is grafana/cisco123

TLS is enabled on cisco_telemetry_mdt plugin, comment below lines in etc/telegraf/telegraf.conf to disable it:

# uncomment below to enable tls for dial-out plguin
tls_cert = "/etc/telegraf/cert/telegraf.crt"
tls_key = "/etc/telegraf/cert/telegraf.key"

certificate ./etc/telegraf/cert/telegraf.crt need be copied to nx-os to verify the collector's identity, then use the below command to enable TLS transport for the destination group, the <certificate name> needs to match the common name of telegraf.crt, it is set to telegraf in build.sh:

switch(config)# telemetry
switch(config-telemetry)# destination-group 1
switch(conf-tm-dest)# ip address <collector address> port 57000 protocol gRPC encoding GPB
switch(conf-tm-dest)# certificate /bootflash/telegraf.crt <certificate name>

TLS need to be enabled for the gNMI plugin as well as nx-os, when configuring feature gRPC on a switch, a default certificate with 1-day validation is auto-generated, to configure the certificate for gRPC on nx-os, copy etc/telegraf/cert/gnmi.pfx to bootflash, then use below commands to import the certificate, the <export password> is set to cisco123 by default, you could modify it in build.sh, these steps are optional as the gnmi plugin in telegraf is set to disable certificate verification.
```
switch(config)# crypto ca trustpoint gnmi_trustpoint
switch(config-trustpoint)# crypto ca import gnmi_trustpoint pkcs12 bootflash:gnmi.pfx <export password>
switch(config)# grpc certificate gnmi_trustpoint
```
This tool will import a couple of pre-built dashboards:
- The fabric dashboard dialout is an example of querying data from telemetry dial-out, you can find the example of the switch telemetry config that is used for this dashboard in telemetry.cfg.
- The fabric dashboard gnmi is an example of querying data from gNMI dial-in.
- The Endpoints shows the arp tables and Mac address tables of all the switches.
- The Interface Counters shows all kinds of interface counters that is collected using the Openconfig model.
- The System Capacity shows the current system utilization of NX-OS using metric collected from icam
Example of telegraf configuration can be found below:
- telegraf.conf.example example of cisco_telemetry_mdt config
- gnmi.conf.example exmaple of gnmi plugin config

Known issue

Before NX-OS 10.1(1), a single subscription of gNMI dial-in can only be SAMPLE or ON_CHANGE, not both. In order to configure different types of subscriptions, need to start two telegraf instances to separate SAMPLE and ON_CHANGE sensor paths. Please take a look at enhancement CSCvu58102 for detail.
MacOS uses the BSD version of sed by default which doesn't work with this script, use brew install gnu-sed to install the gnu version of sed if you are trying this script on MacOS.

Reference

Cisco Nexus 9000 Series NX-OS Programmability Guide, Release 10.3(x)