yamlgraph: Refactor parsing for dynamic resource registration

Avoid use of the reflect package, and use an extensible list of registred
resource kinds. This also has the benefit of removing the empty VirtRes and
AugeasRes struct types when compiling without libvirt and libaugeas.

lib/cli.go

@@ -26,6 +26,7 @@ import (
 
 	"github.com/purpleidea/mgmt/puppet"
 	"github.com/purpleidea/mgmt/yamlgraph"
+	"github.com/purpleidea/mgmt/yamlgraph2"
 
 	"github.com/urfave/cli"
 )
@@ -71,6 +72,14 @@ func run(c *cli.Context) error {
 			File: &y,
 		}
 	}
+	if y := c.String("yaml2"); c.IsSet("yaml2") {
+		if obj.GAPI != nil {
+			return fmt.Errorf("can't combine YAMLv2 GAPI with existing GAPI")
+		}
+		obj.GAPI = &yamlgraph2.GAPI{
+			File: &y,
+		}
+	}
 	if p := c.String("puppet"); c.IsSet("puppet") {
 		if obj.GAPI != nil {
 			return fmt.Errorf("can't combine puppet GAPI with existing GAPI")
@@ -205,6 +214,11 @@ func CLI(program, version string, flags Flags) error {
 					Value: "",
 					Usage: "yaml graph definition to run",
 				},
+				cli.StringFlag{
+					Name:  "yaml2",
+					Value: "",
+					Usage: "yaml graph definition to run (parser v2)",
+				},
 				cli.StringFlag{
 					Name:  "puppet, p",
 					Value: "",