Load config file via a URL (#55)

cmd/root.go

@@ -41,13 +41,15 @@ func Execute() {
 
 var cfgFile string
 var cfgDb string
+var cfgURL string
 var webPort int
 var rpcPort int
 var disableBrand bool
 
 func init() {
 	RootCmd.PersistentFlags().StringVarP(&cfgFile, "config-file", "f", "config.json", "config file")
 	RootCmd.PersistentFlags().StringVarP(&cfgDb, "config-db", "d", "", "config database url")
+	RootCmd.PersistentFlags().StringVarP(&cfgURL, "config-url", "u", "", "config url")
 	RootCmd.PersistentFlags().IntVarP(&webPort, "port", "p", 8888, "port to run web server")
 	RootCmd.PersistentFlags().IntVarP(&rpcPort, "rpc-port", "r", 8889, "port to run RPC server")
 }

cmd/server.go

@@ -24,24 +24,28 @@ var serverCmd = &cobra.Command{
 	Short: "Run checks and server stats",
 	Long:  "Run checks and server stats",
 	Run: func(cmd *cobra.Command, args []string) {
-		if cmd.Flag("config-db").Changed && cmd.Flag("config-file").Changed {
-			log.Fatal("Please specify only one config source")
-		}
 		var configStore config.Store
 		var err error
 		if cmd.Flag("config-db").Changed {
 			log.Println("Config via db")
 			configDb := cmd.Flag("config-db").Value.String()
 			configStore, err = config.NewDBStore(configDb)
 			if err != nil {
-				log.Fatal("Unable to initialise db via :", configDb, " Error: ", err)
+				log.Fatal("DB config error via :", configDb, " Error: ", err)
+			}
+		} else if cmd.Flag("config-url").Changed {
+			log.Println("Config via URL")
+			configURL := cmd.Flag("config-url").Value.String()
+			configStore, err = config.NewURLStore(configURL)
+			if err != nil {
+				log.Fatal("URL config error via :", configURL, " Error: ", err)
 			}
 		} else {
 			log.Println("Config via file")
 			configFile := cmd.Flag("config-file").Value.String()
 			configStore, err = config.NewFileStore(configFile)
 			if err != nil {
-				log.Fatal("Missing or invalid format: ", configFile)
+				log.Fatal("File config error via :", configFile, " Error: ", err)
 			}
 		}
 		runServer(configStore, serverConfig{

config/url_store.go

@@ -0,0 +1,76 @@
+package config
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/jonog/redalert/checks"
+	"github.com/jonog/redalert/notifiers"
+)
+
+type URLStore struct {
+	URL  string
+	data URLStoreData
+}
+
+type URLStoreData struct {
+	Checks        []checks.Config    `json:"checks"`
+	Notifications []notifiers.Config `json:"notifications"`
+	Preferences   Preferences        `json:"preferences"`
+}
+
+func NewURLStore(URL string) (*URLStore, error) {
+	config := &URLStore{URL: URL}
+	err := config.read()
+	if err != nil {
+		return nil, err
+	}
+
+	// create check ID if not present
+	for i := range config.data.Checks {
+		if config.data.Checks[i].ID == "" {
+			config.data.Checks[i].ID = generateID(8)
+		}
+	}
+
+	// create notification ID if not present
+	for i := range config.data.Notifications {
+		if config.data.Notifications[i].ID == "" {
+			config.data.Notifications[i].ID = generateID(8)
+		}
+	}
+
+	return config, nil
+}
+
+func (u *URLStore) read() error {
+	resp, err := http.Get(u.URL)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+	var data URLStoreData
+	err = json.Unmarshal(body, &data)
+	if err != nil {
+		return err
+	}
+	u.data = data
+	return nil
+}
+
+func (u *URLStore) Notifications() ([]notifiers.Config, error) {
+	return u.data.Notifications, nil
+}
+
+func (u *URLStore) Checks() ([]checks.Config, error) {
+	return u.data.Checks, nil
+}
+
+func (u *URLStore) Preferences() (Preferences, error) {
+	return u.data.Preferences, nil
+}