file: add file collector to scrape file size and file modify time which can replace filetime collector (#2205)

Co-authored-by: Jan-Otto Kröpke <mail@jkroepke.de>

docs/collector.file.md

@@ -0,0 +1,40 @@
+# file collector
+
+The file collector exposes modified timestamps and file size of files in the filesystem.
+
+The collector
+
+|||
+-|-
+Metric name prefix  | `file`
+Enabled by default? | No
+
+## Flags
+
+### `--collector.file.file-patterns`
+Comma-separated list of file patterns. Each pattern is a glob pattern that can contain `*`, `?`, and `**` (recursive).
+See https://github.com/bmatcuk/doublestar#patterns for an extended description of the pattern syntax.
+
+## Metrics
+
+| Name                                   | Description            | Type  | Labels |
+|----------------------------------------|------------------------|-------|--------|
+| `windows_file_mtime_timestamp_seconds` | File modification time | gauge | `file` |
+| `windows_file_size_bytes`              | File size              | gauge | `file` |
+
+### Example metric
+
+```
+# HELP windows_file_mtime_timestamp_seconds File modification time
+# TYPE windows_file_mtime_timestamp_seconds gauge
+windows_file_mtime_timestamp_seconds{file="C:\\Users\\admin\\Desktop\\Dashboard.lnk"} 1.726434517e+09
+# HELP windows_file_size_bytes File size
+# TYPE windows_file_size_bytes gauge
+windows_file_size_bytes{file="C:\\Users\\admin\\Desktop\\Dashboard.lnk"} 123
+```
+
+## Useful queries
+_This collector does not yet have any useful queries added, we would appreciate your help adding them!_
+
+## Alerting examples
+_This collector does not yet have alerting examples, we would appreciate your help adding them!_

internal/collector/file/file.go

@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// Copyright 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 windows
+
+package file
+
+import (
+	"fmt"
+	"io/fs"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"github.com/alecthomas/kingpin/v2"
+	"github.com/bmatcuk/doublestar/v4"
+	"github.com/prometheus-community/windows_exporter/internal/mi"
+	"github.com/prometheus-community/windows_exporter/internal/types"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const Name = "file"
+
+type Config struct {
+	FilePatterns []string `yaml:"file-patterns"`
+}
+
+//nolint:gochecknoglobals
+var ConfigDefaults = Config{
+	FilePatterns: []string{},
+}
+
+// A Collector is a Prometheus Collector for collecting file times.
+type Collector struct {
+	config Config
+
+	logger    *slog.Logger
+	fileMTime *prometheus.Desc
+	fileSize  *prometheus.Desc
+}
+
+func New(config *Config) *Collector {
+	if config == nil {
+		config = &ConfigDefaults
+	}
+
+	if config.FilePatterns == nil {
+		config.FilePatterns = ConfigDefaults.FilePatterns
+	}
+
+	c := &Collector{
+		config: *config,
+	}
+
+	return c
+}
+
+func NewWithFlags(app *kingpin.Application) *Collector {
+	c := &Collector{
+		config: ConfigDefaults,
+	}
+	c.config.FilePatterns = make([]string, 0)
+
+	app.Flag(
+		"collector.file.file-patterns",
+		"Comma-separated list of file patterns. Each pattern is a glob pattern that can contain `*`, `?`, and `**` (recursive). See https://github.com/bmatcuk/doublestar#patterns",
+	).Default(strings.Join(ConfigDefaults.FilePatterns, ",")).StringsVar(&c.config.FilePatterns)
+
+	return c
+}
+
+func (c *Collector) GetName() string {
+	return Name
+}
+
+func (c *Collector) Close() error {
+	return nil
+}
+
+func (c *Collector) Build(logger *slog.Logger, _ *mi.Session) error {
+	c.logger = logger.With(slog.String("collector", Name))
+
+	c.logger.Info("file collector is in an experimental state! It may subject to change.")
+
+	c.fileMTime = prometheus.NewDesc(
+		prometheus.BuildFQName(types.Namespace, Name, "mtime_timestamp_seconds"),
+		"File modification time",
+		[]string{"file"},
+		nil,
+	)
+
+	c.fileSize = prometheus.NewDesc(
+		prometheus.BuildFQName(types.Namespace, Name, "size_bytes"),
+		"File size",
+		[]string{"file"},
+		nil,
+	)
+
+	for _, filePattern := range c.config.FilePatterns {
+		basePath, pattern := doublestar.SplitPattern(filePattern)
+
+		_, err := doublestar.Glob(os.DirFS(basePath), pattern, doublestar.WithFilesOnly())
+		if err != nil {
+			return fmt.Errorf("invalid glob pattern: %w", err)
+		}
+	}
+
+	return nil
+}
+
+// Collect sends the metric values for each metric
+// to the provided prometheus Metric channel.
+func (c *Collector) Collect(ch chan<- prometheus.Metric) error {
+	wg := sync.WaitGroup{}
+
+	for _, filePattern := range c.config.FilePatterns {
+		wg.Add(1)
+
+		go func(filePattern string) {
+			defer wg.Done()
+
+			if err := c.collectGlobFilePath(ch, filePattern); err != nil {
+				c.logger.Error("failed collecting metrics for filepath",
+					slog.String("filepath", filePattern),
+					slog.Any("err", err),
+				)
+			}
+		}(filePattern)
+	}
+
+	wg.Wait()
+
+	return nil
+}
+
+func (c *Collector) collectGlobFilePath(ch chan<- prometheus.Metric, filePattern string) error {
+	basePath, pattern := doublestar.SplitPattern(filepath.ToSlash(filePattern))
+	basePathFS := os.DirFS(basePath)
+
+	err := doublestar.GlobWalk(basePathFS, pattern, func(path string, d fs.DirEntry) error {
+		filePath := filepath.Join(basePath, path)
+
+		fileInfo, err := os.Stat(filePath)
+		if err != nil {
+			c.logger.Warn("failed to state file",
+				slog.String("file", filePath),
+				slog.Any("err", err),
+			)
+
+			return nil
+		}
+
+		ch <- prometheus.MustNewConstMetric(
+			c.fileMTime,
+			prometheus.GaugeValue,
+			float64(fileInfo.ModTime().UTC().UnixMicro())/1e6,
+			filePath,
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.fileSize,
+			prometheus.GaugeValue,
+			float64(fileInfo.Size()),
+			filePath,
+		)
+
+		return nil
+	}, doublestar.WithFilesOnly(), doublestar.WithCaseInsensitive())
+	if err != nil {
+		return fmt.Errorf("failed to glob: %w", err)
+	}
+
+	return nil
+}

internal/collector/file/file_test.go

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// Copyright 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 windows
+
+package file_test
+
+import (
+	"testing"
+
+	"github.com/prometheus-community/windows_exporter/internal/collector/file"
+	"github.com/prometheus-community/windows_exporter/internal/utils/testutils"
+)
+
+func BenchmarkCollector(b *testing.B) {
+	testutils.FuncBenchmarkCollector(b, file.Name, file.NewWithFlags)
+}
+
+func TestCollector(t *testing.T) {
+	testutils.TestCollector(t, file.New, &file.Config{
+		FilePatterns: []string{"*.*"},
+	})
+}

pkg/collector/collection.go

@@ -40,6 +40,7 @@ import (
 	"github.com/prometheus-community/windows_exporter/internal/collector/diskdrive"
 	"github.com/prometheus-community/windows_exporter/internal/collector/dns"
 	"github.com/prometheus-community/windows_exporter/internal/collector/exchange"
+	"github.com/prometheus-community/windows_exporter/internal/collector/file"
 	"github.com/prometheus-community/windows_exporter/internal/collector/filetime"
 	"github.com/prometheus-community/windows_exporter/internal/collector/fsrmquota"
 	"github.com/prometheus-community/windows_exporter/internal/collector/gpu"
@@ -111,6 +112,7 @@ func NewWithConfig(config Config) *Collection {
 	collectors[dns.Name] = dns.New(&config.DNS)
 	collectors[exchange.Name] = exchange.New(&config.Exchange)
 	collectors[filetime.Name] = filetime.New(&config.Filetime)
+	collectors[file.Name] = file.New(&config.File)
 	collectors[fsrmquota.Name] = fsrmquota.New(&config.Fsrmquota)
 	collectors[gpu.Name] = gpu.New(&config.GPU)
 	collectors[hyperv.Name] = hyperv.New(&config.HyperV)

pkg/collector/config.go

@@ -30,6 +30,7 @@ import (
 	"github.com/prometheus-community/windows_exporter/internal/collector/diskdrive"
 	"github.com/prometheus-community/windows_exporter/internal/collector/dns"
 	"github.com/prometheus-community/windows_exporter/internal/collector/exchange"
+	"github.com/prometheus-community/windows_exporter/internal/collector/file"
 	"github.com/prometheus-community/windows_exporter/internal/collector/filetime"
 	"github.com/prometheus-community/windows_exporter/internal/collector/fsrmquota"
 	"github.com/prometheus-community/windows_exporter/internal/collector/gpu"
@@ -81,6 +82,7 @@ type Config struct {
 	DNS                dns.Config                `yaml:"dns"`
 	Exchange           exchange.Config           `yaml:"exchange"`
 	Filetime           filetime.Config           `yaml:"filetime"`
+	File               file.Config               `yaml:"file"`
 	Fsrmquota          fsrmquota.Config          `yaml:"fsrmquota"`
 	GPU                gpu.Config                `yaml:"gpu"`
 	HyperV             hyperv.Config             `yaml:"hyperv"`

pkg/collector/map.go

@@ -34,6 +34,7 @@ import (
 	"github.com/prometheus-community/windows_exporter/internal/collector/diskdrive"
 	"github.com/prometheus-community/windows_exporter/internal/collector/dns"
 	"github.com/prometheus-community/windows_exporter/internal/collector/exchange"
+	"github.com/prometheus-community/windows_exporter/internal/collector/file"
 	"github.com/prometheus-community/windows_exporter/internal/collector/filetime"
 	"github.com/prometheus-community/windows_exporter/internal/collector/fsrmquota"
 	"github.com/prometheus-community/windows_exporter/internal/collector/gpu"
@@ -92,6 +93,7 @@ var BuildersWithFlags = map[string]BuilderWithFlags[Collector]{
 	dns.Name:                NewBuilderWithFlags(dns.NewWithFlags),
 	exchange.Name:           NewBuilderWithFlags(exchange.NewWithFlags),
 	filetime.Name:           NewBuilderWithFlags(filetime.NewWithFlags),
+	file.Name:               NewBuilderWithFlags(file.NewWithFlags),
 	fsrmquota.Name:          NewBuilderWithFlags(fsrmquota.NewWithFlags),
 	gpu.Name:                NewBuilderWithFlags(gpu.NewWithFlags),
 	hyperv.Name:             NewBuilderWithFlags(hyperv.NewWithFlags),