Config file reading/writing.

utils/config.go

@@ -0,0 +1,47 @@
+package utils
+
+import (
+	"encoding/json"
+	"os"
+)
+
+// ConfigStructure is structure of main configuration
+type ConfigStructure struct {
+	RootDir             string `json:"rootDir"`
+	DownloadConcurrency int    `json:"downloadConcurrency"`
+}
+
+// Config is configuration for aptly, shared by all modules
+var Config = ConfigStructure{
+	RootDir:             "/var/aptly",
+	DownloadConcurrency: 4,
+}
+
+// LoadConfig loads configuration from json file
+func LoadConfig(filename string, config *ConfigStructure) error {
+	f, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	dec := json.NewDecoder(f)
+	return dec.Decode(&config)
+}
+
+// SaveConfig write configuration to json file
+func SaveConfig(filename string, config *ConfigStructure) error {
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	encoded, err := json.MarshalIndent(&config, "", "  ")
+	if err != nil {
+		return err
+	}
+
+	_, err = f.Write(encoded)
+	return err
+}

utils/config_test.go

@@ -0,0 +1,50 @@
+package utils
+
+import (
+	. "launchpad.net/gocheck"
+	"os"
+	"path/filepath"
+)
+
+type ConfigSuite struct {
+	config ConfigStructure
+}
+
+var _ = Suite(&ConfigSuite{})
+
+func (s *ConfigSuite) TestLoadConfig(c *C) {
+	configname := filepath.Join(c.MkDir(), "aptly.json")
+	f, _ := os.Create(configname)
+	f.WriteString(configFile)
+	f.Close()
+
+	err := LoadConfig(configname, &s.config)
+	c.Assert(err, IsNil)
+	c.Check(s.config.RootDir, Equals, "/opt/aptly/")
+	c.Check(s.config.DownloadConcurrency, Equals, 33)
+}
+
+func (s *ConfigSuite) TestSaveConfig(c *C) {
+	configname := filepath.Join(c.MkDir(), "aptly.json")
+
+	s.config.RootDir = "/tmp/aptly"
+	s.config.DownloadConcurrency = 5
+
+	err := SaveConfig(configname, &s.config)
+	c.Assert(err, IsNil)
+
+	f, _ := os.Open(configname)
+	defer f.Close()
+
+	st, _ := f.Stat()
+	buf := make([]byte, st.Size())
+	f.Read(buf)
+
+	c.Check(string(buf), Equals, ""+
+		"{\n"+
+		"  \"rootDir\": \"/tmp/aptly\",\n"+
+		"  \"downloadConcurrency\": 5\n"+
+		"}")
+}
+
+const configFile = `{"rootDir": "/opt/aptly/", "downloadConcurrency": 33}`