nodewatcher node telemetry provider
The telemetry provider component enables any node to report its operational attributes via a simple HTTP-based hierarchical key-value format. Provider is split into multiple OpenWrt packages as follows:
- nodewatcher-core provides the basic framework for developing telemetry modules, it is required by all other packages.
- nodewatcher-clients provides client-related monitoring (in combination with nodogsplash and olsr-mod-actions plugin).
- nodewatcher-watchdog is responsible for performing periodic testing of node's network sanity and for attempting to recover from weird situations.
- nodewatcher-solar provides power regulator telemetry via the solar package.
- nodewatcher-digitemp provides 1-wire thermometer telemetry via the digitemp package.
Installing these packages should be just a matter of adding our repository to /etc/opkg.conf:
src/gz wlansi http://bindist.wlan-si.net/profiles/PLATFORM
where PLATFORM is one of the supported platforms (currently atheros, brcm24 and ar71xx). Then installing packages should be just a matter of an opkg install.
Remote invocation scripts are installed into /www/cgi-bin and should be accessible via HTTP URL in the form of http://x.y.z.w/cgi-bin/nodewatcher (where x.y.z.w is the node's primary IP address).
Individual telemetry modules are installed into /etc/nodewatcher.d, there is also an example module available in our repository (note that this module is not installed).
The format used by our provider is a simple text format. Lines starting with a semicolon (;) are comments and should be ignored by parsers. Any non-comment line is composed of two parts separated by the first left-wise colon (:). Left part is denoted as key and the right part as value.
All keys form a hierarchy. Namespace atoms are ASCII strings that match the regular expressions based on their position in the hierarchy:
- Top-level namespace atoms must match [A-Za-z-]+. In addition, if a top-level namespace atom contains a capital letter from the range A-Z, the whole atom must be capitalized. Capitalized top-level atoms are reserved for internal use.
- Namespace atoms on lower levels must match [a-z0-9-]+.
Each key may contain multiple namespace atoms separated by dots (.), for example a valid key is wireless.radios.ath0.bssid. The format of value is currently not defined and should be considered of a per-key type defined by the module that outputs it. Value must not contain a newline, as newlines separate key-value pairs.
Currently the only special namespace is META. It contains information about installed modules and their versions. This information is available in META.modules.*.serial and is of integer type. Dots in module names are replaced with dashes (-) when they are used as namespace atoms.
In the future this hierarchical namespace will be centrally allocated to individual nodewatcher telemetry providers, but currently the allocations are ad-hoc and may change.
The following is an example of nodewatcher output from one of the nodes:
; ; nodewatcher monitoring system ; META.version: 2 META.modules.core-clients.serial: 1 iptables.redirection_problem: 0 net.losses: 0 META.modules.core-general.serial: 1 general.uuid: 7061c9ab-2bcc-442e-b0bc-d9959b519e75 general.version: hg general.local_time: 43987 general.uptime: 43987.78 41507.07 general.loadavg: 0.25 0.27 0.30 1/39 523 general.memfree: 14056 general.buffers: 1496 general.cached: 5044 META.modules.core-traffic.serial: 1 iface.eth0.down: 0 iface.eth0.up: 0 iface.eth1.down: 0 iface.eth1.up: 0 iface.wlan0.down: 73108492 iface.wlan0.up: 23656806 iface.edge0.down: 0 iface.edge0.up: 1909300 META.modules.core-vpn.serial: 1 net.vpn.upload_limit: net.vpn.mac: META.modules.core-wireless.serial: 1 wireless.radios.wlan0.bssid: 02:CA:FF:EE:BA:BE wireless.radios.wlan0.essid: open.wlan-si.net wireless.radios.wlan0.frequency: 2.447 wireless.radios.wlan0.mac: 54:E6:FC:F3:7F:54 wireless.radios.wlan0.rts: off wireless.radios.wlan0.frag: off wireless.radios.wlan0.bitrate: wireless.radios.wlan0.signal: 0 wireless.radios.wlan0.noise: 0 wireless.errors: 0 wifi.bssid: 02:CA:FF:EE:BA:BE wifi.essid: open.wlan-si.net wifi.frequency: 2.447 wifi.mac: 54:E6:FC:F3:7F:54 wifi.rts: off wifi.frag: off wifi.bitrate: wifi.signal: 0 wifi.noise: 0 wifi.errors: 0