Enable purgeable space reporting (#3206)

Signed-off-by: Denis <denis@jig-ai.ledeuns.net>
Co-authored-by: Denis <denis@jig-ai.ledeuns.net>

collector/filesystem_bsd.go

@@ -11,9 +11,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build (darwin || dragonfly) && !nofilesystem
+//go:build dragonfly && !nofilesystem
-// +build darwin dragonfly
+// +build dragonfly,!nofilesystem
-// +build !nofilesystem
 
 package collector
 

collector/filesystem_common.go

@@ -75,6 +75,7 @@ type filesystemCollector struct {
 	fsTypeFilter                  deviceFilter
 	sizeDesc, freeDesc, availDesc *prometheus.Desc
 	filesDesc, filesFreeDesc      *prometheus.Desc
+	purgeableDesc                 *prometheus.Desc
 	roDesc, deviceErrorDesc       *prometheus.Desc
 	mountInfoDesc                 *prometheus.Desc
 	logger                        *slog.Logger
@@ -88,6 +89,7 @@ type filesystemStats struct {
 	labels            filesystemLabels
 	size, free, avail float64
 	files, filesFree  float64
+	purgeable         *float64
 	ro, deviceError   float64
 }
 
@@ -129,6 +131,12 @@ func NewFilesystemCollector(logger *slog.Logger) (Collector, error) {
 		filesystemLabelNames, nil,
 	)
 
+	purgeableDesc := prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, subsystem, "purgeable_bytes"),
+		"Filesystem space available including purgeable space (MacOS specific).",
+		filesystemLabelNames, nil,
+	)
+
 	roDesc := prometheus.NewDesc(
 		prometheus.BuildFQName(namespace, subsystem, "readonly"),
 		"Filesystem read-only status.",
@@ -166,6 +174,7 @@ func NewFilesystemCollector(logger *slog.Logger) (Collector, error) {
 		availDesc:        availDesc,
 		filesDesc:        filesDesc,
 		filesFreeDesc:    filesFreeDesc,
+		purgeableDesc:    purgeableDesc,
 		roDesc:           roDesc,
 		deviceErrorDesc:  deviceErrorDesc,
 		mountInfoDesc:    mountInfoDesc,
@@ -223,6 +232,13 @@ func (c *filesystemCollector) Update(ch chan<- prometheus.Metric) error {
 			c.mountInfoDesc, prometheus.GaugeValue,
 			1.0, s.labels.device, s.labels.major, s.labels.minor, s.labels.mountPoint,
 		)
+		if s.purgeable != nil {
+			ch <- prometheus.MustNewConstMetric(
+				c.purgeableDesc, prometheus.GaugeValue,
+				*s.purgeable, s.labels.device, s.labels.mountPoint,
+				s.labels.fsType, s.labels.deviceError,
+			)
+		}
 	}
 	return nil
 }

collector/filesystem_macos.go

@@ -0,0 +1,108 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build darwin && !nofilesystem
+// +build darwin,!nofilesystem
+
+package collector
+
+/*
+#cgo CFLAGS: -x objective-c
+#cgo LDFLAGS: -framework Foundation
+#import <Foundation/Foundation.h>
+Float64 *purgeable(char *path) {
+  CFNumberRef tmp;
+  Float64 *value;
+  NSError *error = nil;
+  NSString *str = [NSString stringWithUTF8String:path];
+  NSURL *fileURL = [[NSURL alloc] initFileURLWithPath:str];
+  NSDictionary *results = [fileURL resourceValuesForKeys:@[NSURLVolumeAvailableCapacityForImportantUsageKey] error:&error];
+  if (results) {
+    if ((tmp = CFDictionaryGetValue((CFDictionaryRef)results, NSURLVolumeAvailableCapacityForImportantUsageKey)) == NULL)
+      return NULL;
+    value = (Float64 *)malloc(sizeof(Float64));
+    if (CFNumberGetValue(tmp, kCFNumberFloat64Type, value)) {
+      return value;
+    }
+  }
+  free(value);
+  return NULL;
+}
+*/
+import "C"
+
+import (
+	"errors"
+	"unsafe"
+)
+
+/*
+#include <sys/param.h>
+#include <sys/ucred.h>
+#include <sys/mount.h>
+#include <stdio.h>
+*/
+import "C"
+
+const (
+	defMountPointsExcluded = "^/(dev)($|/)"
+	defFSTypesExcluded     = "^devfs$"
+	readOnly               = 0x1 // MNT_RDONLY
+)
+
+// Expose filesystem fullness.
+func (c *filesystemCollector) GetStats() (stats []filesystemStats, err error) {
+	var mntbuf *C.struct_statfs
+	count := C.getmntinfo(&mntbuf, C.MNT_NOWAIT)
+	if count == 0 {
+		return nil, errors.New("getmntinfo() failed")
+	}
+
+	mnt := (*[1 << 20]C.struct_statfs)(unsafe.Pointer(mntbuf))
+	stats = []filesystemStats{}
+	for i := 0; i < int(count); i++ {
+		mountpoint := C.GoString(&mnt[i].f_mntonname[0])
+		if c.mountPointFilter.ignored(mountpoint) {
+			c.logger.Debug("Ignoring mount point", "mountpoint", mountpoint)
+			continue
+		}
+
+		device := C.GoString(&mnt[i].f_mntfromname[0])
+		fstype := C.GoString(&mnt[i].f_fstypename[0])
+		if c.fsTypeFilter.ignored(fstype) {
+			c.logger.Debug("Ignoring fs type", "type", fstype)
+			continue
+		}
+
+		var ro float64
+		if (mnt[i].f_flags & readOnly) != 0 {
+			ro = 1
+		}
+
+		stats = append(stats, filesystemStats{
+			labels: filesystemLabels{
+				device:     device,
+				mountPoint: rootfsStripPrefix(mountpoint),
+				fsType:     fstype,
+			},
+			size:      float64(mnt[i].f_blocks) * float64(mnt[i].f_bsize),
+			free:      float64(mnt[i].f_bfree) * float64(mnt[i].f_bsize),
+			avail:     float64(mnt[i].f_bavail) * float64(mnt[i].f_bsize),
+			files:     float64(mnt[i].f_files),
+			filesFree: float64(mnt[i].f_ffree),
+			purgeable: (*float64)(C.purgeable(C.CString(mountpoint))),
+			ro:        ro,
+		})
+	}
+	return stats, nil
+}