Initial commit

.gitignore

@@ -0,0 +1,2 @@
+.idea
+vendor

.goreleaser.yml

@@ -0,0 +1,18 @@
+project_name: streetsweeper
+builds:
+  - main: ./cmd/main.go
+    binary: streetsweeper
+    goos:
+      - darwin
+      - linux
+    goarch:
+      - amd64
+      - 386
+      - arm
+archive:
+  format: tar.gz
+  replacements:
+    darwin: macOS
+  files:
+    - README.md
+    - LICENSE

Gopkg.toml

@@ -0,0 +1,7 @@
+[[constraint]]
+  name = "github.com/fsnotify/fsnotify"
+  revision = "v1.4.2"
+
+[[constraint]]
+  name = "github.com/urfave/cli"
+  revision = "v1.19.1"

LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Rafael Sales
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,15 @@
+# Street sweeper
+
+Street sweeper is a program that monitors a directory and removes old files whenever
+the storage use meets certain condition.
+
+# Usage and examples
+
+* All options:
+
+   `streetsweeper --help`
+
+* When the directory `/etc/lib/motion` has used more than 4GB,
+delete oldest video files until it only has 3.5GB used.
+
+  `streetsweeper --max-size 4000MB --target-size 3500MB /etc/lib/motion`

cmd/main.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+  "log"
+  "github.com/fsnotify/fsnotify"
+  //"github.com/urfave/cli"
+  "../internal/file_sweeper"
+  "fmt"
+  "strings"
+  "errors"
+  "os"
+)
+
+func main() {
+    maxSize, err := parseSize(os.Args[1])
+  if err != nil { log.Fatal(err) }
+  targetSize, err := parseSize(os.Args[2])
+  if err != nil { log.Fatal(err) }
+  path := os.Args[3]
+
+  log.Printf("Initializing. Path: %s | Max size: %d | Target size: %d", path, maxSize, targetSize)
+
+  onWrite := func() { file_sweeper.Run(path, maxSize, targetSize) }
+  onWrite()
+  fileWatcher(path, onWrite)
+}
+
+func parseSize(formattedSize string) (bytes int64, err error) {
+  formattedSize = strings.TrimSpace(formattedSize)
+
+  _, err = fmt.Sscanf(formattedSize, "%dKB", &bytes)
+  if err == nil { return bytes * 1024, nil }
+
+  _, err = fmt.Sscanf(formattedSize, "%dMB", &bytes)
+  if err == nil { return bytes * 1024 * 1024, nil}
+
+  _, err = fmt.Sscanf(formattedSize, "%dGB", &bytes)
+  if err == nil { return bytes * 1024 * 1024 * 1024, nil }
+
+  return -1, errors.New("Unknown size format: " + formattedSize)
+}
+
+func fileWatcher(path string, onWrite func()) {
+  watcher, err := fsnotify.NewWatcher()
+  if err != nil { log.Fatal(err) }
+  defer watcher.Close()
+
+  done := make(chan bool)
+  go func() {
+    for {
+      select {
+      case event := <-watcher.Events:
+        if event.Op == fsnotify.Write || event.Op == fsnotify.Create {
+          log.Printf("Write detected: %s", event.Name)
+          onWrite()
+        }
+      case err := <-watcher.Errors:
+        log.Println("Error: %s", err)
+      }
+    }
+  }()
+
+  err = watcher.Add(path)
+  if err != nil { log.Fatal(err) }
+  <-done
+}

internal/file_sweeper/main.go

@@ -0,0 +1,61 @@
+package file_sweeper
+
+import (
+  "os"
+  "path/filepath"
+  "log"
+  "sort"
+)
+
+func Run(path string, maxSize int64, targetSize int64) {
+  currentSize, _ := dirSize(path)
+  log.Printf("Path: %s | Current size: %d", path, currentSize)
+
+  if currentSize > maxSize {
+    log.Printf( "Path: %s | Over max size - Current size: %d | Max size: %d", path, currentSize, maxSize)
+    deleteOldFiles(path, currentSize, targetSize)
+  }
+}
+
+func dirSize(path string) (int64, error) {
+  var size int64
+  os.Open(path)
+  err := filepath.Walk(path, func(a string, info os.FileInfo, err error) error {
+    if !info.IsDir() {
+      size += info.Size()
+    }
+    return err
+  })
+  return size, err
+}
+
+func deleteOldFiles(path string, currentSize int64, targetSize int64) {
+  var sizeDeleted int64
+
+  dir, err := os.Open(path)
+  if err != nil { log.Fatal(err) }
+
+  entries, err := dir.Readdir(-1)
+  if err != nil { log.Fatal(err) }
+
+  sort.SliceStable(entries, func(i, j int) bool {
+    return entries[i].ModTime().Before(entries[j].ModTime())
+  })
+
+  for _, entry := range entries {
+    if !entry.IsDir() {
+      filePath := filepath.Join(path, entry.Name())
+      modifiedAt := entry.ModTime().UTC().String()
+      size := entry.Size()
+
+      log.Printf( "Deleting: %s | Modified at: %s | Size: %d", filePath, modifiedAt, size)
+      os.Remove(filePath)
+      sizeDeleted += size
+    }
+
+    if currentSize - sizeDeleted < targetSize {
+      log.Printf( "Deleted a total of %d", sizeDeleted)
+      return
+    }
+  }
+}