switch to config file and implement src path filter

pkg/config/config.go

@@ -0,0 +1,106 @@
+// Copyright (C) 2022 Marius Schellenberger
+
+package config
+
+import (
+	"errors"
+	"os"
+	"regexp"
+
+	"gopkg.in/yaml.v3"
+)
+
+func ParseFile(file string) (cfg *Config, err error) {
+	if file == "" {
+		return nil, errors.New("missing config file")
+	}
+	f, err := os.Open(file)
+	if err != nil {
+		return
+	}
+	defer f.Close()
+	cfg = new(Config)
+	err = yaml.NewDecoder(f).Decode(cfg)
+	if err != nil {
+		return
+	}
+	err = Validate(cfg)
+	return
+}
+
+type Config struct {
+	Server Server         `yaml:"server"`
+	Cache  Cache          `yaml:"cache"`
+	Path   string         `yaml:"path"`
+	REPath *regexp.Regexp `yaml:"-"`
+}
+
+type Server struct {
+	HTTP   Listen `yaml:"http"`
+	WebDav Listen `yaml:"webdav"`
+	Cache  Listen `yaml:"cache"`
+	Plain  Listen `yaml:"plain"`
+}
+
+type Listen struct {
+	Addr string `yaml:"addr"`
+}
+
+type Cache struct {
+	Metadata  string `yaml:"metadata"`
+	Src       Path   `yaml:"src"`
+	Dst       Path   `yaml:"dst"`
+	Preloads  int    `yaml:"preloads"`
+	Buffer    int    `yaml:"buffer"`
+	Quota     int64  `yaml:"quota"`
+	BlockSFTP *bool  `yaml:"blockSFTP"`
+}
+
+type Path struct {
+	Path string `yaml:"path"`
+	Key  string `yaml:"key"`
+}
+
+const (
+	defListenHTTP = "127.0.0.1:8080"
+	defPreloads   = 1
+	defBuffer     = 8192
+	defQuota      = 1
+	defBlockSFTP  = true
+	gib           = 1024 * 1024 * 1024
+)
+
+func Validate(cfg *Config) error {
+	if cfg.Server.HTTP.Addr == "" {
+		cfg.Server.HTTP.Addr = defListenHTTP
+	}
+	c := cfg.Cache
+	if c.Metadata == "" {
+		return errors.New("cache.metadata is empty")
+	}
+	if c.Src.Path == "" {
+		return errors.New("cache.src is empty")
+	}
+	if c.Dst.Path == "" {
+		return errors.New("cache.dst is empty")
+	}
+	if c.Preloads <= 0 {
+		c.Preloads = defPreloads
+	}
+	if c.Buffer < 1024 {
+		c.Buffer = defBuffer
+	}
+	if c.Quota < 1 {
+		c.Quota = defQuota
+	}
+	c.Quota *= gib
+	if c.BlockSFTP == nil {
+		c.BlockSFTP = new(bool)
+		*c.BlockSFTP = defBlockSFTP
+	}
+	var err error
+	if cfg.Path != "" {
+		cfg.REPath, err = regexp.Compile(cfg.Path)
+	}
+	return err
+}