Initial commit.

configuration/config.go

@@ -0,0 +1,78 @@
+package configuration
+
+import (
+	// stdlib
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	// other
+	"gopkg.in/yaml.v2"
+)
+
+// This structure represents application's configuration.
+type config struct {
+	Debug    bool `yaml:"debug"`
+	Database struct {
+		DSN        string `yaml:"dsn"`
+		Parameters string `yaml:"parameters"`
+		Prefix     string `yaml:"prefix"`
+	} `yaml:"database"`
+	Groups struct {
+		Default string `yaml:"default"`
+		Groups  []struct {
+			Group string   `yaml:"group"`
+			Users []string `yaml:"users"`
+		}
+	} `yaml:"groups"`
+}
+
+// Checks neccessary parameters for filling.
+func (c *config) checkParameters() {
+	if c.Database.DSN == "" {
+		log.Fatalln("database/dsn parameter isn't filled, don't know to which database I should connect!")
+	}
+}
+
+// Initialize initializes configuration structure by reading configuration
+// file and populate structure with it's data.
+func (c *config) Initialize() {
+	// If -config wasn't provided or empty - do nothing.
+	if configPath == "" {
+		log.Fatalln("-config parameter is empty, don't know where configuration is!")
+	}
+
+	// Normalize configuration path.
+	if strings.HasPrefix(configPath, "~") {
+		userDir, err := os.UserHomeDir()
+		if err != nil {
+			log.Fatalln("Failed to get user's home directory for user! Error was: " + err.Error())
+		}
+
+		configPath = strings.Replace(configPath, "~", userDir, 1)
+	}
+
+	absolutePath, err := filepath.Abs(configPath)
+	if err != nil {
+		log.Fatalln("Failed to get configuration file's absolute path! Error was: " + err.Error())
+	}
+
+	// Read and parse.
+	dataAsBytes, err1 := ioutil.ReadFile(absolutePath)
+	if err1 != nil {
+		log.Fatalln("Failed to read configuration file! Error was: " + err1.Error())
+	}
+
+	err2 := yaml.Unmarshal(dataAsBytes, c)
+	if err2 != nil {
+		log.Fatalln("Failed to parse configuration file! Error was: " + err2.Error())
+	}
+
+	if c.Debug {
+		log.Printf("Configuration parsed: %+v\n", c)
+	}
+
+	c.checkParameters()
+}

configuration/exported.go

@@ -0,0 +1,19 @@
+package configuration
+
+import (
+	// stdlib
+	"flag"
+)
+
+var (
+	Cfg *config
+
+	configPath string
+)
+
+// Initialize initializes package.
+func Initialize() {
+	Cfg = &config{}
+
+	flag.StringVar(&configPath, "config", "", "Path to configuration file")
+}