Get version from datastore with version command

- Retrieve CalicoVersion and ClusterType from datastore and print with
  version command

calicoctl/commands/version.go

@@ -33,7 +33,7 @@ func init() {
 
 func Version(args []string) {
 	doc := `Usage:
-  calicoctl version
+  calicoctl version [--config=<CONFIG>]
 
 Options:
   -h --help             Show this screen.
@@ -53,9 +53,9 @@ Description:
 		return
 	}
 
-	fmt.Println("Version:     ", VERSION)
-	fmt.Println("Build date:  ", BUILD_DATE)
-	fmt.Println("Git commit:  ", GIT_REVISION)
+	fmt.Println("Client Version:   ", VERSION)
+	fmt.Println("Build date:       ", BUILD_DATE)
+	fmt.Println("Git commit:       ", GIT_REVISION)
 
 	// Load the client config and connect.
 	cf := parsedArgs["--config"].(string)
@@ -66,8 +66,18 @@ Description:
 	}
 	cfg := client.Config()
 
-	val, _, _ := cfg.GetFelixConfig("ClusterVersion", "")
-	fmt.Println("Cluster Version:  ", val)
-	val, _, _ = cfg.GetFelixConfig("ClusterType", "")
+	val, assigned, err := cfg.GetFelixConfig("CalicoVersion", "")
+	if err != nil {
+		val = fmt.Sprintf("unknown (%s)", err)
+	} else if !assigned {
+		val = "unknown"
+	}
+	fmt.Println("Server Version:   ", val)
+	val, assigned, err = cfg.GetFelixConfig("ClusterType", "")
+	if err != nil {
+		val = fmt.Sprintf("unknown (%s)", err)
+	} else if !assigned {
+		val = "unknown"
+	}
 	fmt.Println("Cluster Type:     ", val)
 }