New collector: openwrt

[fis]

OpenWrt has a system bus called uBus. We could add an (optional, enabled by default in the OpenWrt build) collector similar to the node_exporter systemd collector, reporting service/system statistics available over the bus.

[fis]

What's on the uBus?

The following dump is from a minimal OpenWrt r8614-78ca6a5578 build on Linksys WRT32X. Only potentially interesting calls (from the monitoring perspective) are included; there's a lot of calls that modify device state.

• obj dnsmasq
  • call metrics
• obj hostapd.wlan0
  • call get_clients
  • call list_bans
  • call get_features
• obj hostapd.wlan1
• obj log
  • call read (args: int lines, bool stream, bool oneshot)
• obj network
• obj network.device
  • call status (args: string name)
• obj network.interface
  • call dump
• obj network.interface.X
  • call status
• obj network.wireless
  • call status
• obj service
  • call list (args: string name, bool verbose)
  • call get_data (args: string name, string instance, string type)
  • call state (args: bool spawn, string name)
• obj system
  • call board
  • call info
  • call reboot
  • call watchdog (args: int frequency, int timeout, bool magicclose, bool stop)
  • call signal (args: int pid, int signum)
  • call sysupgrade (args: string path, string prefix, string command)

Potentially interesting calls

ubus call dnsmasq metrics

{
        "dns_cache_inserted": 547229,
        "dns_cache_live_freed": 0,
        "dns_queries_forwarded": 187265,
        "dns_auth_answered": 0,
        "dns_local_answered": 263961,
        "bootp": 0,
        "pxe": 0,
        "dhcp_ack": 107,
        "dhcp_decline": 0,
        "dhcp_discover": 45,
        "dhcp_inform": 0,
        "dhcp_nak": 0,
        "dhcp_offer": 45,
        "dhcp_release": 0,
        "dhcp_request": 107,
        "noanswer": 0,
        "leases_allocated_4": 14,
        "leases_pruned_4": 12,
        "leases_allocated_6": 0,
        "leases_pruned_6": 0
}

ubus call hostapd.wlanX get_clients

{
        "freq": 5180,
        "clients": {
                "xx:xx:xx:xx": { auth, assoc, authorized, preauth, wds, wmm, ht, vht, wps, mfp, rrm, aid },
                ...
        }
}

ubus call {network.device status / network.interface.X status}

These are more or less redundant with the netdev collector, so probably don't need to be included.

ubus call network.wireless status

Mostly static state, not so interesting as metrics. Though the radioX.config.channel might be a plausible metric, if it reflects an automatically assigned channel state.

ubus call service list

{
        ...,
        "nano-exporter": {
                "instances": {
                        "instance1": {
                                "running": true,
                                "pid": 11606,
                                "command": [
                                        "\/usr\/sbin\/nano-exporter",
                                        "--foreground"
                                ],
                                "term_timeout": 5
                        }
                }
        },
        ...

ubus call system board

{
        "kernel": "4.14.82",
        "hostname": "OpenWrt",
        "system": "ARMv7 Processor rev 1 (v7l)",
        "model": "Linksys WRT32X",
        "board_name": "armada-385-linksys-venom",
        "release": {
                "distribution": "OpenWrt",
                "version": "SNAPSHOT",
                "revision": "r8614-78ca6a5578",
                "target": "mvebu\/cortexa9",
                "description": "OpenWrt SNAPSHOT r8614-78ca6a5578"
        }
}

ubus call system info

{
        "localtime": 1543982110,
        "uptime": 345449,
        "load": [
                0,
                0,
                0
        ],
        "memory": {
                "total": 523218944,
                "free": 330235904,
                "shared": 102400,
                "buffered": 3940352
        },
        "swap": {
                "total": 0,
                "free": 0
        }
}

[fis]

Possible metrics

• dnsmasq
  • openwrt_dnsmasq_X N - all the metrics from dnsmasq metrics call
• hostapd
  • openwrt_hostapd_authorized_clients{interface="wlanX"} N
  • openwrt_hostapd_unauthorized_clients{interface="wlanX"} N
• service
  • openwrt_service_running_instances{name="x"} N
• system
  • openwrt_system_board_info{kernel,hostname,system,model,board} 1
  • openwrt_system_release_info{distribution,version,revision,target} 1