Merge pull request #208 from adam-dej/master

[modules] Add zpool module

README.md

@@ -5,7 +5,7 @@
 [![Test Coverage](https://codeclimate.com/github/tobi-wan-kenobi/bumblebee-status/badges/coverage.svg)](https://codeclimate.com/github/tobi-wan-kenobi/bumblebee-status/coverage)
 [![Issue Count](https://codeclimate.com/github/tobi-wan-kenobi/bumblebee-status/badges/issue_count.svg)](https://codeclimate.com/github/tobi-wan-kenobi/bumblebee-status)
 
-**Many, many thanks to all contributors! As of now, 24 of the modules are from various contributors (!), and only 16 from myself.**
+**Many, many thanks to all contributors! As of now, 25 of the modules are from various contributors (!), and only 16 from myself.**
 
 bumblebee-status is a modular, theme-able status line generator for the [i3 window manager](https://i3wm.org/).
 
@@ -163,6 +163,7 @@ Modules and commandline utilities are only required for modules, the core itself
 * dbus-send (for module 'bluetooth')
 * nvidia-smi (for module 'nvidiagpu')
 * sensors (for module 'sensors', as fallback)
+* zpool (for module 'zpool')
 
 # Examples
 Here are some screenshots for all themes that currently exist:

bumblebee/modules/zpool.py

@@ -0,0 +1,172 @@
+"""Displays info about zpools present on the system
+
+Parameters:
+   * zpool.list: Comma-separated list of zpools to display info for. If empty, info for all zpools
+                 is displayed. (Default: "")
+   * zpool.format: Format string, tags {name}, {used}, {left}, {size}, {percentfree}, {percentuse},
+                   {status}, {shortstatus}, {fragpercent}, {deduppercent} are supported.
+                   (Default: "{name} {used}/{size} ({percentfree}%)")
+   * zpool.showio: Show also widgets detailing current read and write I/O (Default: true)
+   * zpool.ioformat: Format string for I/O widget, tags {ops} (operations per seconds) and {band}
+                     (bandwidth) are supported. (Default: "{band}")
+   * zpool.warnfree: Warn if free space is below this percentage (Default: 10)
+   * zpool.sudo: Use sudo when calling the `zpool` binary. (Default: false)
+
+Option `zpool.sudo` is intended for Linux users using zfsonlinux older than 0.7.0: In pre-0.7.0
+releases of zfsonlinux regular users couldn't invoke even informative commands such as
+`zpool list`. If this option is true, command `zpool list` is invoked with sudo. If this option
+is used, the following (or ekvivalent) must be added to the `sudoers(5)`:
+
+```
+<username/ALL> ALL = (root) NOPASSWD: /usr/bin/zpool list
+```
+
+Be aware of security implications of doing this!
+"""
+
+import time
+import bumblebee.engine
+from bumblebee.util import execute, bytefmt, asbool
+
+
+class Module(bumblebee.engine.Module):
+    def __init__(self, engine, config):
+        widgets = []
+        super(Module, self).__init__(engine, config, widgets)
+
+        self._includelist = set(filter(lambda x: len(x) > 0,
+                                       self.parameter("list", default="").split(',')))
+        self._format = self.parameter("format", default="{name} {shortstatus} {used}/{size} " +
+                                                        "({percentfree}%)")
+        self._usesudo = asbool(self.parameter("sudo", default=False))
+        self._showio = asbool(self.parameter("showio", default=True))
+        self._ioformat = self.parameter("ioformat", default="{band}")
+        self._warnfree = int(self.parameter("warnfree", default=10))
+
+        self._update_widgets(widgets)
+
+    def update(self, widgets):
+        self._update_widgets(widgets)
+
+    def state(self, widget):
+        if widget.name.endswith("__read"):
+            return "poolread"
+        elif widget.name.endswith("__write"):
+            return "poolwrite"
+
+        state = widget.get("state")
+        if state == "FAULTED":
+            return [state, "critical"]
+        elif state == "DEGRADED" or widget.get("percentfree") < self._warnfree:
+            return [state, "warning"]
+
+        return state
+
+    def _update_widgets(self, widgets):
+        # zpool list -H: List all zpools, use script mode (no headers and tabs as separators).
+        raw_zpools = execute(('sudo ' if self._usesudo else '') + 'zpool list -H').split('\n')
+
+        for widget in widgets:
+            widget.set("visited", False)
+
+        for raw_zpool in raw_zpools:
+            try:
+                # Ignored fields (assigned to _) are "expandsz" and "altroot"
+                name, size, alloc, free, _, frag, cap, dedup, health, _ = raw_zpool.split('\t')
+                cap = cap.rstrip('%')
+                percentuse=int(cap)
+                percentfree=100-percentuse
+                # There is a command, zpool iostat, which is however blocking and was therefore
+                # causing issues.
+                # Instead, we read file `/proc/spl/kstat/zfs/<poolname>/io` which contains
+                # cumulative I/O statistics since boot (or pool creation). We store these values
+                # (and timestamp) during each widget update, and during the next widget update we
+                # use them to compute delta of transferred bytes, and using the last and current
+                # timestamp the rate at which they have been transferred.
+                with open("/proc/spl/kstat/zfs/{}/io".format(name), "r") as f:
+                    # Third row provides data we need, we are interested in the first 4 values.
+                    # More info about this file can be found here:
+                    # https://github.com/zfsonlinux/zfs/blob/master/lib/libspl/include/sys/kstat.h#L580
+                    # The 4 values are:
+                    # nread, nwritten, reads, writes
+                    iostat = list(map(int, f.readlines()[2].split()[:4]))
+            except (ValueError, IOError):
+                # Unable to parse info about this pool, skip it
+                continue
+
+            if self._includelist and name not in self._includelist:
+                continue
+
+            widget = self.widget(name)
+            if not widget:
+                widget = bumblebee.output.Widget(name=name)
+                widget.set("last_iostat", [0, 0, 0, 0])
+                widget.set("last_timestamp", 0)
+                widgets.append(widget)
+
+            delta_iostat = [b - a for a, b in zip(iostat, widget.get("last_iostat"))]
+            widget.set("last_iostat", iostat)
+
+            # From docs:
+            #   > Note that even though the time is always returned as a floating point number, not
+            #   > all systems provide time with a better precision than 1 second.
+            # Be aware that that may affect the precision of reported I/O
+            # Also, during one update cycle the reported I/O may be garbage if the system time
+            # was changed.
+            timestamp = time.time()
+            delta_timestamp = widget.get("last_timestamp") - timestamp
+            widget.set("last_timestamp", time.time())
+
+            # abs is there because sometimes the result is -0
+            rate_iostat = [abs(x / delta_timestamp) for x in delta_iostat]
+            nread, nwritten, reads, writes = rate_iostat
+
+            # theme.minwidth is not set since these values are not expected to change
+            # rapidly
+            widget.full_text(self._format.format(name=name, used=alloc, left=free, size=size,
+                                                 percentfree=percentfree, percentuse=percentuse,
+                                                 status=health,
+                                                 shortstatus=self._shortstatus(health),
+                                                 fragpercent=frag, deduppercent=dedup))
+            widget.set("state", health)
+            widget.set("percentfree", percentfree)
+            widget.set("visited", True)
+
+            if self._showio:
+                wname, rname = [name + x for x in ["__write", "__read"]]
+                widget_w = self.widget(wname)
+                widget_r = self.widget(rname)
+                if not widget_w or not widget_r:
+                    widget_r = bumblebee.output.Widget(name=rname)
+                    widget_w = bumblebee.output.Widget(name=wname)
+                    widgets.extend([widget_r, widget_w])
+                for w in [widget_r, widget_w]:
+                    w.set("theme.minwidth", self._ioformat.format(ops=9999,
+                                                                  band=bytefmt(999.99*(1024**2))))
+                    w.set("visited", True)
+                widget_w.full_text(self._ioformat.format(ops=round(writes),
+                                                         band=bytefmt(nwritten)))
+                widget_r.full_text(self._ioformat.format(ops=round(reads),
+                                                         band=bytefmt(nread)))
+
+        for widget in widgets:
+            if widget.get("visited") == False:
+                widgets.remove(widget)
+
+    @staticmethod
+    def _shortstatus(status):
+        # From `zpool(8)`, section Device Failure and Recovery:
+        # A pool's health status is described by one of three states: online, degraded, or faulted.
+        # An online pool has all devices operating normally.  A degraded pool is one in which one
+        # or more devices have failed, but the data is still available due to a redundant
+        # configuration.  A faulted pool has corrupted metadata, or one or more faulted devices, and
+        # insufficient replicas to continue functioning.
+        shortstate = {
+            "DEGRADED": "DEG",
+            "FAULTED": "FLT",
+            "ONLINE": "ONL",
+        }
+        try:
+            return shortstate[status]
+        except KeyError:
+            return ""

themes/icons/ascii.json

@@ -89,5 +89,12 @@
 	},
 	"uptime": {
         "prefix": "uptime"
+	},
+	"zpool": {
+		"poolread": {"prefix": "pool read "},
+		"poolwrite": {"prefix": "pool write "},
+		"ONLINE": {"prefix": "pool"},
+		"FAULTED": {"prefix": "pool (!)"},
+		"DEGRADED": {"prefix": "pool (!)"}
 	}
 }

themes/icons/awesome-fonts.json

@@ -19,7 +19,13 @@
 	"items": {"prefix": "" },
 	"uptime": {"prefix": "" }
 	},
-
+	"zpool": {
+		"poolread": {"prefix": "→ "},
+		"poolwrite": {"prefix": "← "},
+		"ONLINE": {"prefix": ""},
+		"FAULTED": {"prefix": "!"},
+		"DEGRADED": {"prefix": "!"}
+	},
 	"cmus": {
 		"playing": { "prefix": "" },
 		"paused": { "prefix": "" },