Fixed usage of NOMAD_CLI_NO_COLOR env variable.

.changelog/11168.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+cli: Fixed a bug where the NOMAD_CLI_NO_COLOR environment variable was not always applied
+```

command/meta.go

@@ -154,9 +154,12 @@ func (m *Meta) allNamespaces() bool {
 }
 
 func (m *Meta) Colorize() *colorstring.Colorize {
+	_, coloredUi := m.Ui.(*cli.ColoredUi)
+	noColor := m.noColor || !coloredUi || !terminal.IsTerminal(int(os.Stdout.Fd()))
+
 	return &colorstring.Colorize{
 		Colors:  colorstring.DefaultColors,
-		Disable: m.noColor || !terminal.IsTerminal(int(os.Stdout.Fd())),
+		Disable: noColor,
 		Reset:   true,
 	}
 }

command/meta_test.go

@@ -2,9 +2,14 @@ package command
 
 import (
 	"flag"
+	"os"
 	"reflect"
 	"sort"
 	"testing"
+
+	"github.com/kr/pty"
+	"github.com/mitchellh/cli"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestMeta_FlagSet(t *testing.T) {
@@ -53,3 +58,63 @@ func TestMeta_FlagSet(t *testing.T) {
 		}
 	}
 }
+
+func TestMeta_Colorize(t *testing.T) {
+	type testCaseSetupFn func(*testing.T, *Meta)
+
+	cases := []struct {
+		Name        string
+		SetupFn     testCaseSetupFn
+		ExpectColor bool
+	}{
+		{
+			Name:        "disable colors if UI is not colored",
+			ExpectColor: false,
+		},
+		{
+			Name: "colors if UI is colored",
+			SetupFn: func(t *testing.T, m *Meta) {
+				m.Ui = &cli.ColoredUi{}
+			},
+			ExpectColor: true,
+		},
+		{
+			Name: "disable colors via CLI flag",
+			SetupFn: func(t *testing.T, m *Meta) {
+				m.Ui = &cli.ColoredUi{}
+
+				fs := m.FlagSet("colorize_test", FlagSetDefault)
+				err := fs.Parse([]string{"-no-color"})
+				assert.NoError(t, err)
+			},
+			ExpectColor: false,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.Name, func(t *testing.T) {
+			// Create fake test terminal.
+			_, tty, err := pty.Open()
+			if err != nil {
+				t.Fatalf("%v", err)
+			}
+			defer tty.Close()
+
+			oldStdout := os.Stdout
+			defer func() { os.Stdout = oldStdout }()
+			os.Stdout = tty
+
+			// Run test case.
+			m := &Meta{}
+			if tc.SetupFn != nil {
+				tc.SetupFn(t, m)
+			}
+
+			if tc.ExpectColor {
+				assert.False(t, m.Colorize().Disable)
+			} else {
+				assert.True(t, m.Colorize().Disable)
+			}
+		})
+	}
+}