Implement basic plugin loading mechanism.

cmd/odo/odo.go

@@ -6,16 +6,23 @@ import (
 	"github.com/golang/glog"
 	"github.com/posener/complete"
 	"github.com/redhat-developer/odo/pkg/config"
+	"github.com/redhat-developer/odo/pkg/log"
 	"github.com/redhat-developer/odo/pkg/odo/cli"
 	"github.com/redhat-developer/odo/pkg/odo/cli/version"
+	"github.com/redhat-developer/odo/pkg/odo/events"
 	"github.com/redhat-developer/odo/pkg/odo/util"
 	"github.com/redhat-developer/odo/pkg/odo/util/completion"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"os"
+	"path/filepath"
+	"plugin"
+	"strings"
 )
 
 func main() {
+	loadPlugins()
+
 	// create the complete command
 	root := cli.NewCmdOdo(cli.OdoRecommendedName, cli.OdoRecommendedName)
 	rootCmp := createCompletion(root)
@@ -112,3 +119,43 @@ func createCompletion(root *cobra.Command) complete.Command {
 
 	return rootCmp
 }
+
+func loadPlugins() {
+	configDir, err := config.GetPluginsDir()
+	if err != nil {
+		panic(err)
+	}
+
+	bus := events.GetEventBus()
+
+	err = filepath.Walk(configDir, func(path string, info os.FileInfo, err error) error {
+		if strings.HasSuffix(path, ".so") {
+			// Open the plugin library
+			plug, err := plugin.Open(path)
+			if err != nil {
+				fmt.Println(err)
+				os.Exit(1)
+			}
+
+			// Look up the exporter Listener variable
+			candidate, err := plug.Lookup("Listener")
+			if err != nil {
+				fmt.Println(err)
+				os.Exit(1)
+			}
+
+			// Assert that Listener is indeed a Listener :)
+			listener, ok := candidate.(events.Listener)
+			if !ok {
+				log.Error("exported Listener variable is not implementing the Listener interface")
+				os.Exit(1)
+			}
+
+			bus.RegisterToAll(listener)
+		}
+		return nil
+	})
+	if err != nil {
+		panic(err)
+	}
+}

pkg/config/config.go

@@ -59,6 +59,35 @@ type ConfigInfo struct {
 	Config
 }
 
+func GetConfigDir() (string, error) {
+	currentUser, err := user.Current()
+	if err != nil {
+		return "", err
+	}
+
+	configDir := filepath.Join(currentUser.HomeDir, ".odo")
+
+	// Check whether directory present or not
+	_, err = os.Stat(filepath.Dir(configDir))
+	if os.IsNotExist(err) {
+		err = os.MkdirAll(filepath.Dir(configDir), 0755)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	return configDir, nil
+}
+
+func GetPluginsDir() (string, error) {
+	configDir, err := GetConfigDir()
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Join(configDir, "plugins"), nil
+}
+
 func getDefaultConfigFile() string {
 	currentUser, err := user.Current()
 	if err != nil {