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Fabric Configuration

  • --fabric-mode <mode-name (collapsed-core or spine-leaf) - Fabric mode to use, default is spine-leaf; in case of collapsed-core mode, there will be no VXLAN configured and only 2 switches will be used
  • --ntp-servers <servers>- Comma-separated list of NTP servers to use, default is time.cloudflare.com,time1.google.com,time2.google.com,time3.google.com,time4.google.com, it'll be used for both control nodes and switches
  • --dhcpd <mode-name> (isc or hedgehog) - DHCP server to use, default is isc; hedgehog DHCP server enables use of on-demand DHCP for multiple IPv4/VLAN namespaces and overlapping IP ranges, and it adds DHCP leases into the Fabric API

For more information about how to use hhfab init, run hhfab init --help.

Configure switch users

It's currently only possible by using a config yaml file for the hhfab init -c <config-file.yaml> command. You can specify users to be configured on the switches in the following format:

config:
    ...
    fabric:
        ...
        switchUsers:
          - name: test
            password: $5$oj/NxDtFw3eTyini$VHwdjWXSNYRxlFMu.1S5ZlGJbUF/CGmCAZIBroJlax4
            role: operator

Where name is the username, password is the password hash created with openssl passwd -5 command, and role is the role of the user, one of admin or operator (read-only access to sonic-cli command on the switches).

Forward switch metrics and logs

There is an option to enable Grafana Alloy on all switches to forward metrics and logs to the configured targets using Prometheus Remote-Write API and Loki API. If those APIs are available from Control Node(s), but not from the switches, it's possible to enable HTTP Proxy on Control Node(s) that will be used by Grafana Alloy running on the switches to access the configured targets. It could be done by passing --control-proxy=true to hhfab init.

Metrics includes port speeds, counters, errors, operational status, transceivers, fans, power supplies, temperature sensors, BGP neighbors, LLDP neighbors, and more. Logs include agent logs.

Configuring the exporters and targets is currently only possible by using a config yaml file for the hhfab init -c <config-file.yaml> command using the following format:

config:
    ...
    fabric:
        ...
        alloy:
            agentScrapeIntervalSeconds: 120
            controlProxyURL: http://172.30.1.1:31028
            lokiTargets:
                grafana_cloud: # target name, multiple targets can be configured
                    basicAuth: # optional
                        password: "<password>"
                        username: "<username>"
                    labels: # labels to be added to all logs
                        env: env-1
                    url: https://logs-prod-021.grafana.net/loki/api/v1/push
                    useControlProxy: true # if the Loki API is not available from the switches directly, use the Control Node as a proxy
            prometheusTargets:
                grafana_cloud: # target name, multiple targets can be configured
                    basicAuth: # optional
                        password: "<password>"
                        username: "<username>"
                    labels: # labels to be added to all metrics
                        env: env-1
                    sendIntervalSeconds: 120
                    url: https://prometheus-prod-36-prod-us-west-0.grafana.net/api/prom/push
                    useControlProxy: true # if the Loki API is not available from the switches directly, use the Control Node as a proxy
            unixExporterCollectors: # list of node-exporter collectors to enable, https://grafana.com/docs/alloy/latest/reference/components/prometheus.exporter.unix/#collectors-list
                - cpu
                - filesystem
                - loadavg
                - meminfo
            unixExporterEnabled: true
            unixScrapeIntervalSeconds: 120

For additional options, see the AlloyConfig struct in Fabric repo.

Last update: May 7, 2024
Created: January 22, 2024