stratis: new plugin to monitor stratis filesystem

plugins/disk/stratis

@@ -0,0 +1,152 @@
+#!/usr/bin/python3 -tt
+# -*- coding: utf-8 -*-
+
+"""Munin plugin to monitor stratis pools and filesystems.
+
+Copyright 2020 Kim B. Heino, Foobar Oy
+License GPLv2+
+
+#%# capabilities=autoconf
+#%# family=auto
+"""
+
+import os
+import subprocess
+import sys
+
+
+def safename(variable):
+    """Return safe variable name."""
+    ret = []
+    for letter in variable:
+        if letter.isalnum():
+            ret.append(letter)
+        else:
+            ret.append('_')
+    return ''.join(ret)
+
+
+def run_binary(arg):
+    """Run binary and return output."""
+    try:
+        cmd = subprocess.Popen(
+            arg, shell=False, close_fds=True, bufsize=-1,
+            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        return cmd.communicate()[0].decode('utf-8', 'ignore')
+    except OSError:
+        return ''
+
+
+def parse_unit(number, unit):
+    """Parse "1.60 TiB" to bytes."""
+    number = float(number)
+    if unit == 'TiB':
+        return number * 1024 * 1024 * 1024 * 1024
+    if unit == 'GiB':
+        return number * 1024 * 1024 * 1024
+    if unit == 'MiB':
+        return number * 1024 * 1024
+    if unit == 'KiB':
+        return number * 1024
+    return number
+
+
+def find_pools():
+    """Return list of found pools and filesystems."""
+    pool = []
+    for line in run_binary(['/usr/bin/stratis', 'pool']).splitlines():
+        if line.startswith('Name  '):
+            continue
+        line = line.split()
+        total = parse_unit(line[1], line[2])
+        used = parse_unit(line[4], line[5])
+        free = parse_unit(line[7], line[8])
+        pool.append((line[0], total, used, free))
+
+    files = []
+    dflist = run_binary(['/usr/bin/df']).splitlines()
+    for line in run_binary(['/usr/bin/stratis', 'filesystem']).splitlines():
+        if line.startswith('Pool Name ') or '-snap-' in line:
+            continue
+        line = line.split()
+        df_used = used = parse_unit(line[2], line[3])
+        for dfline in dflist:
+            if line[9] not in dfline:  # match by uuid
+                continue
+            df_used = int(dfline.split()[2]) * 1024
+        files.append((line[0], line[1], used, df_used))
+    return sorted(pool), sorted(files)
+
+
+def config(pools, files):
+    """Print plugin config."""
+    print('multigraph stratis_pool')
+    print('graph_title Stratis pools usage')
+    print('graph_info Stratis pools usage in percent.')
+    print('graph_category disk')
+    print('graph_vlabel %')
+    print('graph_args --lower-limit 0 --upper-limit 100')
+    print('graph_scale no')
+    for item in pools:
+        name = safename(item[0])
+        print('{}.label Pool {} usage'.format(name, item[0]))
+        print('{}.warning 92'.format(name))
+        print('{}.critical 98'.format(name))
+
+    print('multigraph stratis_fs')
+    print('graph_title Stratis filesystems usage')
+    print('graph_info Stratis filesystems pool usage.')
+    print('graph_category disk')
+    print('graph_vlabel Pool usage')
+    print('graph_args --base 1024 --lower-limit 0')
+    first = True
+    for item in files:
+        name = safename(item[0] + '_' + item[1])
+        print('{}.label Filesystem {}/{}'.format(name, item[0], item[1]))
+        if first:
+            print('{}.draw AREA'.format(name))
+            first = False
+        else:
+            print('{}.draw STACK'.format(name))
+
+    print('multigraph stratis_thin')
+    print('graph_title Stratis thin filesystems usage vs df')
+    print('graph_info Stratis thin filesystems usage divided by df, in '
+          'percents.')
+    print('graph_category disk')
+    print('graph_vlabel %')
+    print('graph_args --base 1000')
+    for item in files:
+        name = safename(item[0] + '_' + item[1])
+        print('{}.label {}/{} usage vs df'.format(name, item[0], item[1]))
+        print('{}.warning 150'.format(name))
+
+    if os.environ.get('MUNIN_CAP_DIRTYCONFIG') == '1':
+        fetch(pools, files)
+
+
+def fetch(pools, files):
+    """Print values."""
+    print('multigraph stratis_pool')
+    for item in pools:
+        name = safename(item[0])
+        print('{}.value {}'.format(name, item[2] * 100 / item[1]))
+
+    print('multigraph stratis_fs')
+    for item in files:
+        name = safename(item[0] + '_' + item[1])
+        print('{}.value {}'.format(name, item[2]))
+
+    print('multigraph stratis_thin')
+    for item in files:
+        name = safename(item[0] + '_' + item[1])
+        print('{}.value {}'.format(name, item[2] * 100 / item[3]))
+
+
+if __name__ == '__main__':
+    if len(sys.argv) > 1 and sys.argv[1] == 'autoconf':
+        print('yes' if find_pools()[0] else 'no')
+    elif len(sys.argv) > 1 and sys.argv[1] == 'config':
+        config(*find_pools())
+    else:
+        fetch(*find_pools())