command/apply: basic implementation

command/apply.go

@@ -1,18 +1,67 @@
 package command
 
 import (
+	"flag"
+	"fmt"
 	"strings"
 
+	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/terraform"
 	"github.com/mitchellh/cli"
 )
 
 // ApplyCommand is a Command implementation that applies a Terraform
 // configuration and actually builds or changes infrastructure.
 type ApplyCommand struct {
-	Ui cli.Ui
+	TFConfig *terraform.Config
+	Ui       cli.Ui
 }
 
-func (c *ApplyCommand) Run(_ []string) int {
+func (c *ApplyCommand) Run(args []string) int {
+	cmdFlags := flag.NewFlagSet("apply", flag.ContinueOnError)
+	cmdFlags.Usage = func() { c.Ui.Error(c.Help()) }
+	if err := cmdFlags.Parse(args); err != nil {
+		return 1
+	}
+
+	args = cmdFlags.Args()
+	if len(args) != 1 {
+		c.Ui.Error(
+			"The apply command expects only one argument with the path\n" +
+				"to a Terraform configuration.\n")
+		cmdFlags.Usage()
+		return 1
+	}
+
+	b, err := config.Load(args[0])
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Error loading blueprint: %s", err))
+		return 1
+	}
+
+	tfconfig := c.TFConfig
+	tfconfig.Config = b
+
+	tf, err := terraform.New(tfconfig)
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Error initializing Terraform: %s", err))
+		return 1
+	}
+
+	diff, err := tf.Diff(nil)
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Error running diff: %s", err))
+		return 1
+	}
+
+	state, err := tf.Apply(nil, diff)
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Error applying diff: %s", err))
+		return 1
+	}
+
+	c.Ui.Output(strings.TrimSpace(state.String()))
+
 	return 0
 }
 

commands.go

@@ -25,7 +25,8 @@ func init() {
 	Commands = map[string]cli.CommandFactory{
 		"apply": func() (cli.Command, error) {
 			return &command.ApplyCommand{
-				Ui: ui,
+				TFConfig: &TFConfig,
+				Ui:       ui,
 			}, nil
 		},