Use TOML as config file format in downloader (#405)

* Use TOML as config file format.

* Parse command line a second time if config file was loaded.

* Handle default values correctly.

* Use same names for config file options and command line options.

cmd/csaf_downloader/config.go

@@ -9,44 +9,130 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"net/http"
 	"os"
 
+	"github.com/BurntSushi/toml"
+	"github.com/csaf-poc/csaf_distribution/v2/util"
+	"github.com/jessevdk/go-flags"
 	"github.com/mitchellh/go-homedir"
 )
 
-const defaultWorker = 2
+const (
+	defaultWorker = 2
+	defaultPreset = "mandatory"
+)
 
 type config struct {
-	Directory            *string  `short:"d" long:"directory" description:"DIRectory to store the downloaded files in" value-name:"DIR"`
+	Directory            *string  `short:"d" long:"directory" description:"DIRectory to store the downloaded files in" value-name:"DIR" toml:"directory"`
-	Insecure             bool     `long:"insecure" description:"Do not check TLS certificates from provider"`
+	Insecure             bool     `long:"insecure" description:"Do not check TLS certificates from provider" toml:"insecure"`
-	IgnoreSignatureCheck bool     `long:"ignoresigcheck" description:"Ignore signature check results, just warn on mismatch"`
+	IgnoreSignatureCheck bool     `long:"ignoresigcheck" description:"Ignore signature check results, just warn on mismatch" toml:"ignoresigcheck"`
-	Version              bool     `long:"version" description:"Display version of the binary" no-ini:"true"`
+	Version              bool     `long:"version" description:"Display version of the binary" toml:"-"`
-	Verbose              bool     `long:"verbose" short:"v" description:"Verbose output"`
+	Verbose              bool     `long:"verbose" short:"v" description:"Verbose output" toml:"verbose"`
-	Rate                 *float64 `long:"rate" short:"r" description:"The average upper limit of https operations per second (defaults to unlimited)"`
+	Rate                 *float64 `long:"rate" short:"r" description:"The average upper limit of https operations per second (defaults to unlimited)" toml:"rate"`
-	Worker               int      `long:"worker" short:"w" description:"NUMber of concurrent downloads" value-name:"NUM"`
+	Worker               int      `long:"worker" short:"w" description:"NUMber of concurrent downloads" value-name:"NUM" toml:"worker"`
 
-	ExtraHeader http.Header `long:"header" short:"H" description:"One or more extra HTTP header fields"`
+	ExtraHeader http.Header `long:"header" short:"H" description:"One or more extra HTTP header fields" toml:"header"`
 
-	RemoteValidator        string   `long:"validator" description:"URL to validate documents remotely" value-name:"URL"`
+	RemoteValidator        string   `long:"validator" description:"URL to validate documents remotely" value-name:"URL" toml:"validator"`
-	RemoteValidatorCache   string   `long:"validatorcache" description:"FILE to cache remote validations" value-name:"FILE"`
+	RemoteValidatorCache   string   `long:"validatorcache" description:"FILE to cache remote validations" value-name:"FILE" toml:"validatorcache"`
-	RemoteValidatorPresets []string `long:"validatorpreset" description:"One or more presets to validate remotely" default:"mandatory"`
+	RemoteValidatorPresets []string `long:"validatorpreset" description:"One or more PRESETS to validate remotely" value-name:"PRESETS" toml:"validatorpreset"`
 
-	Config *string `short:"c" long:"config" description:"Path to config ini file" value-name:"INI-FILE" no-ini:"true"`
+	Config string `short:"c" long:"config" description:"Path to config TOML file" value-name:"TOML-FILE" toml:"-"`
 }
 
-// iniPaths are the potential file locations of the the config file.
+// configPaths are the potential file locations of the the config file.
-var iniPaths = []string{
+var configPaths = []string{
-	"~/.config/csaf/downloader.ini",
+	"~/.config/csaf/downloader.toml",
-	"~/.csaf_downloader.ini",
+	"~/.csaf_downloader.toml",
-	"csaf_downloader.ini",
+	"csaf_downloader.toml",
 }
 
-// findIniFile looks for a file in the pre-defined paths in "iniPaths".
+// newConfig returns a new configuration.
+func newConfig() *config {
+	return &config{
+		Worker:                 defaultWorker,
+		RemoteValidatorPresets: []string{defaultPreset},
+	}
+}
+
+// parseArgsConfig parses the command line and if need a config file.
+func parseArgsConfig() ([]string, *config, error) {
+
+	// Parse the command line first.
+	cmdLineCfg := newConfig()
+	parser := flags.NewParser(cmdLineCfg, flags.Default)
+	parser.Usage = "[OPTIONS] domain..."
+	args, err := parser.Parse()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Directly quit if the version flag was set.
+	if cmdLineCfg.Version {
+		fmt.Println(util.SemVersion)
+		os.Exit(0)
+	}
+
+	var path string
+	// Do we have a config file explicitly given by command line?
+	if cmdLineCfg.Config != "" {
+		path = cmdLineCfg.Config
+	} else {
+		path = findConfigFile()
+	}
+	// No config file -> We are good.
+	if path == "" {
+		return args, cmdLineCfg, nil
+	}
+
+	if path, err = homedir.Expand(path); err != nil {
+		return nil, nil, err
+	}
+
+	// Load the config file
+	fileCfg := &config{}
+	if err := fileCfg.load(path); err != nil {
+		return nil, nil, err
+	}
+
+	// Parse command line a second time to overwrite the
+	// loaded config at places where explicitly command line
+	// options where given.
+	args, err = flags.NewParser(fileCfg, flags.Default).Parse()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Re-establish default values.
+	if fileCfg.Worker == 0 {
+		fileCfg.Worker = defaultWorker
+	}
+	if fileCfg.RemoteValidatorPresets == nil {
+		fileCfg.RemoteValidatorPresets = []string{defaultPreset}
+	}
+
+	return args, fileCfg, nil
+}
+
+// load loads a configuration from file.
+func (cfg *config) load(path string) error {
+	md, err := toml.DecodeFile(path, &cfg)
+	if err != nil {
+		return err
+	}
+	if undecoded := md.Undecoded(); len(undecoded) != 0 {
+		return fmt.Errorf("could not parse %q from %q", undecoded, path)
+	}
+	return nil
+}
+
+// findConfigFile looks for a file in the pre-defined paths in "configPath".
 // The returned value will be the name of file if found, otherwise an empty string.
-func findIniFile() string {
+func findConfigFile() string {
-	for _, f := range iniPaths {
+	for _, f := range configPaths {
 		name, err := homedir.Expand(f)
 		if err != nil {
 			log.Printf("warn: %v\n", err)
@@ -64,3 +150,14 @@ func (cfg *config) prepare() error {
 	// TODO: Implement me!
 	return nil
 }
+
+// errCheck checks if err is not nil and terminates
+// the program if so.
+func errCheck(err error) {
+	if err != nil {
+		if flags.WroteHelp(err) {
+			os.Exit(0)
+		}
+		log.Fatalf("error: %v\n", err)
+	}
+}

cmd/csaf_downloader/main.go

@@ -11,25 +11,11 @@ package main
 
 import (
 	"context"
-	"fmt"
 	"log"
 	"os"
 	"os/signal"
-
-	"github.com/csaf-poc/csaf_distribution/v2/util"
-	"github.com/jessevdk/go-flags"
-	"github.com/mitchellh/go-homedir"
 )
 
-func errCheck(err error) {
-	if err != nil {
-		if flags.WroteHelp(err) {
-			os.Exit(0)
-		}
-		log.Fatalf("error: %v\n", err)
-	}
-}
-
 func run(cfg *config, domains []string) error {
 	d, err := newDownloader(cfg)
 	if err != nil {
@@ -47,32 +33,8 @@ func run(cfg *config, domains []string) error {
 
 func main() {
 
-	cfg := &config{
+	domains, cfg, err := parseArgsConfig()
-		Worker: defaultWorker,
-	}
-
-	parser := flags.NewParser(cfg, flags.Default)
-	parser.Usage = "[OPTIONS] domain..."
-	domains, err := parser.Parse()
 	errCheck(err)
-
-	if cfg.Version {
-		fmt.Println(util.SemVersion)
-		return
-	}
-
-	if cfg.Config != nil {
-		iniParser := flags.NewIniParser(parser)
-		iniParser.ParseAsDefaults = true
-		name, err := homedir.Expand(*cfg.Config)
-		errCheck(err)
-		errCheck(iniParser.ParseFile(name))
-	} else if iniFile := findIniFile(); iniFile != "" {
-		iniParser := flags.NewIniParser(parser)
-		iniParser.ParseAsDefaults = true
-		errCheck(iniParser.ParseFile(iniFile))
-	}
-
 	errCheck(cfg.prepare())
 
 	if len(domains) == 0 {

docs/csaf_downloader.md

@@ -17,8 +17,8 @@ Application Options:
   -H, --header=                    One or more extra HTTP header fields
       --validator=URL              URL to validate documents remotely
       --validatorcache=FILE        FILE to cache remote validations
-      --validatorpreset=       One or more presets to validate remotely (default: mandatory)
+      --validatorpreset=PRESETS    One or more PRESETS to validate remotely (default: [mandatory])
-  -c, --config=INI-FILE        Path to config ini file
+  -c, --config=TOML-FILE           Path to config TOML file
 
 Help Options:
   -h, --help                       Show this help message
@@ -35,9 +35,9 @@ have taken countermeasures to limit this.
 
 If no config file is explictly given the follwing places are searched for a config file:
 ```
-~/.config/csaf/downloader.ini
+~/.config/csaf/downloader.toml
-~/.csaf_downloader.ini
+~/.csaf_downloader.toml
-csaf_downloader.ini
+csaf_downloader.toml
 ```
 
 with `~` expanding to `$HOME` on unixoid systems and `%HOMEPATH` on Windows systems.
@@ -53,5 +53,5 @@ worker            = 2
 # header          # not set by default
 # validator       # not set by default
 # validatorcache  # not set by default
-validatorpreset   = "mandatory"
+validatorpreset   = ["mandatory"]
 ```