command/plan: nice plan formatting

command/format_plan.go

@@ -0,0 +1,97 @@
+package command
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/hashicorp/terraform/terraform"
+	"github.com/mitchellh/colorstring"
+)
+
+// FormatPlan takes a plan and returns a
+func FormatPlan(p *terraform.Plan, c *colorstring.Colorize) string {
+	if c == nil {
+		c = &colorstring.Colorize{
+			Colors: colorstring.DefaultColors,
+			Reset:  false,
+		}
+	}
+
+	buf := new(bytes.Buffer)
+
+	// We want to output the resources in sorted order to make things
+	// easier to scan through, so get all the resource names and sort them.
+	names := make([]string, 0, len(p.Diff.Resources))
+	for name, _ := range p.Diff.Resources {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+
+	// Go through each sorted name and start building the output
+	for _, name := range names {
+		rdiff := p.Diff.Resources[name]
+
+		// Determine the color for the text (green for adding, yellow
+		// for change, red for delete), and symbol, and output the
+		// resource header.
+		color := "yellow"
+		symbol := "~"
+		if rdiff.RequiresNew() {
+			color = "green"
+			symbol = "+"
+		} else if rdiff.Destroy {
+			color = "red"
+			symbol = "-"
+		}
+		buf.WriteString(c.Color(fmt.Sprintf(
+			"[%s]%s %s\n",
+			color, symbol, name)))
+
+		// Get all the attributes that are changing, and sort them. Also
+		// determine the longest key so that we can align them all.
+		keyLen := 0
+		keys := make([]string, 0, len(rdiff.Attributes))
+		for key, _ := range rdiff.Attributes {
+			// Skip the ID since we do that specially
+			if key == "id" {
+				continue
+			}
+
+			keys = append(keys, key)
+			if len(key) > keyLen {
+				keyLen = len(key)
+			}
+		}
+		sort.Strings(keys)
+
+		// Go through and output each attribute
+		for _, attrK := range keys {
+			attrDiff := rdiff.Attributes[attrK]
+
+			v := attrDiff.New
+			if attrDiff.NewComputed {
+				v = "<computed>"
+			}
+
+			newResource := ""
+			if attrDiff.RequiresNew && rdiff.Destroy {
+				newResource = " (forces new resource)"
+			}
+
+			buf.WriteString(fmt.Sprintf(
+				"  %s:%s %#v => %#v%s\n",
+				attrK,
+				strings.Repeat(" ", keyLen-len(attrK)),
+				attrDiff.Old,
+				v,
+				newResource))
+		}
+
+		// Write the reset color so we don't overload the user's terminal
+		buf.WriteString(c.Color("[reset]\n"))
+	}
+
+	return strings.TrimSpace(buf.String())
+}

command/hook_ui.go

@@ -29,9 +29,6 @@ func (h *UiHook) PreApply(
 
 func (h *UiHook) PreDiff(
 	id string, s *terraform.ResourceState) (terraform.HookAction, error) {
-	h.once.Do(h.init)
-
-	h.ui.Output(fmt.Sprintf("%s: Calculating diff", id))
 	return terraform.HookActionContinue, nil
 }
 

command/plan.go

@@ -109,8 +109,6 @@ func (c *PlanCommand) Run(args []string) int {
 		return 0
 	}
 
-	c.Ui.Output(strings.TrimSpace(plan.String()))
-
 	if outPath != "" {
 		log.Printf("[INFO] Writing plan output to: %s", outPath)
 		f, err := os.Create(outPath)
@@ -124,6 +122,16 @@ func (c *PlanCommand) Run(args []string) int {
 		}
 	}
 
+	if outPath == "" {
+		c.Ui.Output(strings.TrimSpace(planHeaderNoOutput)+"\n")
+	} else {
+		c.Ui.Output(fmt.Sprintf(
+			strings.TrimSpace(planHeaderYesOutput)+"\n",
+			outPath))
+	}
+
+	c.Ui.Output(FormatPlan(plan, nil))
+
 	return 0
 }
 
@@ -159,3 +167,28 @@ Options:
 func (c *PlanCommand) Synopsis() string {
 	return "Show changes between Terraform config and infrastructure"
 }
+
+const planHeaderNoOutput = `
+The Terraform execution plan has been generated and is shown below.
+Resources are shown in alphabetical order for quick scanning. Green resources
+will be created (or destroyed and then created if an existing resource
+exists), yellow resources are being changed in-place, and red resources
+will be destroyed.
+
+Note: You didn't specify an "-out" parameter to save this plan, so when
+"apply" is called, Terraform can't guarantee this is what will execute.
+`
+
+const planHeaderYesOutput = `
+The Terraform execution plan has been generated and is shown below.
+Resources are shown in alphabetical order for quick scanning. Green resources
+will be created (or destroyed and then created if an existing resource
+exists), yellow resources are being changed in-place, and red resources
+will be destroyed.
+
+Your plan was also saved to the path below. Call the "apply" subcommand
+with this plan file and Terraform will exactly execute this execution
+plan.
+
+Path: %s
+`