add support for per-device blueprints (#136)

blueprints are now saved in boltdb with mdmctl
blueprints work in a similar way to munki manifests:
The devices will use a site_default blueprint, otherwise will
look up one based on serial number.
Other blueprints can be nested

cmd/mdmctl/apply.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/go-kit/kit/log"
+	"github.com/micromdm/micromdm/core/apply"
+)
+
+type applyCommand struct {
+	config   *ClientConfig
+	applysvc apply.Service
+}
+
+func (cmd *applyCommand) setup() error {
+	cfg, err := LoadClientConfig()
+	if err != nil {
+		return err
+	}
+	cmd.config = cfg
+	logger := log.NewLogfmtLogger(os.Stderr)
+	applysvc, err := apply.NewClient(cfg.ServerURL, logger, cfg.APIToken)
+	if err != nil {
+		return err
+	}
+	cmd.applysvc = applysvc
+	return nil
+}
+
+func (cmd *applyCommand) Run(args []string) error {
+	if len(args) < 1 {
+		cmd.Usage()
+		os.Exit(1)
+	}
+	if err := cmd.setup(); err != nil {
+		return err
+	}
+	var run func([]string) error
+	switch strings.ToLower(args[0]) {
+	case "blueprints":
+		run = cmd.applyBlueprint
+	default:
+		cmd.Usage()
+		os.Exit(1)
+	}
+	return run(args[1:])
+}
+
+func (cmd *applyCommand) Usage() error {
+	const applyUsage = `
+Apply a resource.
+
+Valid resource types:
+
+  * blueprints
+
+Examples:
+  # Get a list of devices
+  mdmctl apply blueprints -f /path/to/blueprint.json
+
+`
+	fmt.Println(applyUsage)
+	return nil
+}
+
+func (cmd *applyCommand) applyBlueprint(args []string) error {
+	flagset := flag.NewFlagSet("blueprints", flag.ExitOnError)
+	flagset.Usage = usageFor(flagset, "mdmctl apply blueprints [flags]")
+	if err := flagset.Parse(args); err != nil {
+		return err
+	}
+	return nil
+}