Support JSON and template format with nomad CLI

command/alloc_status.go

@@ -38,11 +38,17 @@ Alloc Status Options:
   -short
     Display short output. Shows only the most recent task event.
 
-  -stats 
-    Display detailed resource usage statistics
+  -stats
+    Display detailed resource usage statistics.
 
   -verbose
     Show full information.
+
+  -format
+    Display specified format, "json" or "template".
+
+  -t
+    Sets the template with golang templates format.
 `
 
 	return strings.TrimSpace(helpText)
@@ -54,12 +60,15 @@ func (c *AllocStatusCommand) Synopsis() string {
 
 func (c *AllocStatusCommand) Run(args []string) int {
 	var short, displayStats, verbose bool
+	var format, tmpl string
 
 	flags := c.Meta.FlagSet("alloc-status", FlagSetClient)
 	flags.Usage = func() { c.Ui.Output(c.Help()) }
 	flags.BoolVar(&short, "short", false, "")
 	flags.BoolVar(&verbose, "verbose", false, "")
 	flags.BoolVar(&displayStats, "stats", false, "")
+	flags.StringVar(&format, "format", "default", "")
+	flags.StringVar(&tmpl, "t", "", "")
 
 	if err := flags.Parse(args); err != nil {
 		return 1
@@ -130,6 +139,23 @@ func (c *AllocStatusCommand) Run(args []string) int {
 		return 1
 	}
 
+	// If output format is specified, format and output the data
+	if format != "default" {
+		f, err := DataFormat(format, tmpl)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error getting formatter: %s", err))
+			return 1
+		}
+
+		out, err := f.TransformData(alloc)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error transform the data: %s", err))
+			return 1
+		}
+		c.Ui.Output(out)
+		return 0
+	}
+
 	var statsErr error
 	var stats *api.AllocResourceUsage
 	stats, statsErr = client.Allocations().Stats(alloc, nil)

command/data_format.go

@@ -0,0 +1,58 @@
+package command
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"text/template"
+)
+
+//DataFormatter is a transformer of the data.
+type DataFormatter interface {
+	// TransformData should return transformed string data.
+	TransformData(interface{}) (string, error)
+}
+
+// DataFormat returns the data formatter specified format.
+func DataFormat(format, tmpl string) (DataFormatter, error) {
+	switch format {
+	case "json":
+		return &JSONFormat{}, nil
+	case "template":
+		return &TemplateFormat{tmpl}, nil
+	}
+	return nil, fmt.Errorf("Unsupported format is specified.")
+}
+
+type JSONFormat struct {
+}
+
+// TransformData returns JSON format string data.
+func (p *JSONFormat) TransformData(data interface{}) (string, error) {
+	out, err := json.MarshalIndent(&data, "", "    ")
+	if err != nil {
+		return "", err
+	}
+
+	return string(out), nil
+}
+
+type TemplateFormat struct {
+	tmpl string
+}
+
+// TransformData returns template format string data.
+func (p *TemplateFormat) TransformData(data interface{}) (string, error) {
+	var out io.Writer = new(bytes.Buffer)
+	if len(p.tmpl) == 0 {
+		return "", fmt.Errorf("template needs to be specified the golang templates.")
+	}
+
+	t := template.Must(template.New("format").Parse(p.tmpl))
+	err := t.Execute(out, data)
+	if err != nil {
+		return "", err
+	}
+	return fmt.Sprint(out), nil
+}

command/data_format_test.go

@@ -0,0 +1,41 @@
+package command
+
+import (
+	"testing"
+)
+
+type testData struct {
+	Region string
+	ID     string
+	Name   string
+}
+
+const expectJSON = `{
+    "Region": "global",
+    "ID": "1",
+    "Name": "example"
+}`
+
+var (
+	tData        = testData{"global", "1", "example"}
+	testFormat   = map[string]string{"json": "", "template": "{{.Region}}"}
+	expectOutput = map[string]string{"json": expectJSON, "template": "global"}
+)
+
+func TestDataFormat(t *testing.T) {
+	for k, v := range testFormat {
+		fm, err := DataFormat(k, v)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		result, err := fm.TransformData(tData)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		if result != expectOutput[k] {
+			t.Fatalf("expected output: %s, actual: %s", expectOutput[k], result)
+		}
+	}
+}

command/eval_status.go

@@ -31,6 +31,12 @@ Eval Status Options:
 
   -verbose
     Show full information.
+
+  -format
+    Display specified format, "json" or "template".
+
+  -t
+    Sets the template with golang templates format.
 `
 
 	return strings.TrimSpace(helpText)
@@ -42,11 +48,14 @@ func (c *EvalStatusCommand) Synopsis() string {
 
 func (c *EvalStatusCommand) Run(args []string) int {
 	var monitor, verbose bool
+	var format, tmpl string
 
 	flags := c.Meta.FlagSet("eval-status", FlagSetClient)
 	flags.Usage = func() { c.Ui.Output(c.Help()) }
 	flags.BoolVar(&monitor, "monitor", false, "")
 	flags.BoolVar(&verbose, "verbose", false, "")
+	flags.StringVar(&format, "format", "default", "")
+	flags.StringVar(&tmpl, "t", "", "")
 
 	if err := flags.Parse(args); err != nil {
 		return 1
@@ -124,6 +133,23 @@ func (c *EvalStatusCommand) Run(args []string) int {
 		return 1
 	}
 
+	// If output format is specified, format and output the data
+	if format != "default" {
+		f, err := DataFormat(format, tmpl)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error getting formatter: %s", err))
+			return 1
+		}
+
+		out, err := f.TransformData(eval)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error transform the data: %s", err))
+			return 1
+		}
+		c.Ui.Output(out)
+		return 0
+	}
+
 	failureString, failures := evalFailureStatus(eval)
 	triggerNoun, triggerSubj := getTriggerDetails(eval)
 	statusDesc := eval.StatusDescription

command/node_status.go

@@ -30,6 +30,8 @@ type NodeStatusCommand struct {
 	list_allocs bool
 	self        bool
 	stats       bool
+	format      string
+	tmpl        string
 }
 
 func (c *NodeStatusCommand) Help() string {
@@ -66,6 +68,12 @@ Node Status Options:
 
   -verbose
     Display full information.
+
+  -format
+    Display specified format, "json" or "template".
+
+  -t
+    Sets the template with golang templates format.
 `
 	return strings.TrimSpace(helpText)
 }
@@ -83,6 +91,8 @@ func (c *NodeStatusCommand) Run(args []string) int {
 	flags.BoolVar(&c.list_allocs, "allocs", false, "")
 	flags.BoolVar(&c.self, "self", false, "")
 	flags.BoolVar(&c.stats, "stats", false, "")
+	flags.StringVar(&c.format, "format", "default", "")
+	flags.StringVar(&c.tmpl, "t", "", "")
 
 	if err := flags.Parse(args); err != nil {
 		return 1
@@ -216,6 +226,23 @@ func (c *NodeStatusCommand) Run(args []string) int {
 		return 1
 	}
 
+	// If output format is specified, format and output the data
+	if c.format != "default" {
+		f, err := DataFormat(c.format, c.tmpl)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error getting formatter: %s", err))
+			return 1
+		}
+
+		out, err := f.TransformData(node)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error transform the data: %s", err))
+			return 1
+		}
+		c.Ui.Output(out)
+		return 0
+	}
+
 	return c.formatNode(client, node)
 }
 

command/status.go

@@ -46,6 +46,12 @@ Status Options:
 
   -verbose
     Display full information.
+
+  -format
+    Display specified format, "json" or "template".
+
+  -t
+    Sets the template with golang templates format.
 `
 	return strings.TrimSpace(helpText)
 }
@@ -56,12 +62,15 @@ func (c *StatusCommand) Synopsis() string {
 
 func (c *StatusCommand) Run(args []string) int {
 	var short bool
+	var format, tmpl string
 
 	flags := c.Meta.FlagSet("status", FlagSetClient)
 	flags.Usage = func() { c.Ui.Output(c.Help()) }
 	flags.BoolVar(&short, "short", false, "")
 	flags.BoolVar(&c.showEvals, "evals", false, "")
 	flags.BoolVar(&c.verbose, "verbose", false, "")
+	flags.StringVar(&format, "format", "default", "")
+	flags.StringVar(&tmpl, "t", "", "")
 
 	if err := flags.Parse(args); err != nil {
 		return 1
@@ -145,6 +154,23 @@ func (c *StatusCommand) Run(args []string) int {
 		return 1
 	}
 
+	// If output format is specified, format and output the data
+	if format != "default" {
+		f, err := DataFormat(format, tmpl)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error getting formatter: %s", err))
+			return 1
+		}
+
+		out, err := f.TransformData(job)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error transform the data: %s", err))
+			return 1
+		}
+		c.Ui.Output(out)
+		return 0
+	}
+
 	// Check if it is periodic
 	sJob, err := convertApiJob(job)
 	if err != nil {