cli: add config command and config validate subcommand to nomad CLI

command/agent/command.go

@@ -294,14 +294,14 @@ func (c *Command) readConfig() *Config {
 
 	config.Server.DefaultSchedulerConfig.Canonicalize()
 
-	if !c.isValidConfig(config, cmdConfig) {
+	if !c.IsValidConfig(config, cmdConfig) {
 		return nil
 	}
 
 	return config
 }
 
-func (c *Command) isValidConfig(config, cmdConfig *Config) bool {
+func (c *Command) IsValidConfig(config, cmdConfig *Config) bool {
 
 	// Check that the server is running in at least one mode.
 	if !(config.Server.Enabled || config.Client.Enabled) {

command/agent/command_test.go

@@ -398,7 +398,7 @@ func TestIsValidConfig(t *testing.T) {
 			mui := cli.NewMockUi()
 			cmd := &Command{Ui: mui}
 			config := DefaultConfig().Merge(&tc.conf)
-			result := cmd.isValidConfig(config, DefaultConfig())
+			result := cmd.IsValidConfig(config, DefaultConfig())
 			if tc.err == "" {
 				// No error expected
 				assert.True(t, result, mui.ErrorWriter.String())

command/commands.go

@@ -204,6 +204,16 @@ func Commands(metaPtr *Meta, agentUi cli.Ui) map[string]cli.CommandFactory {
 				Meta: meta,
 			}, nil
 		},
+		"config": func() (cli.Command, error) {
+			return &ConfigCommand{
+				Meta: meta,
+			}, nil
+		},
+		"config validate": func() (cli.Command, error) {
+			return &ConfigValidateCommand{
+				Meta: meta,
+			}, nil
+		},
 		// operator debug was released in 0.12 as debug. This top-level alias preserves compatibility
 		"debug": func() (cli.Command, error) {
 			return &OperatorDebugCommand{

command/config.go

@@ -0,0 +1,38 @@
+package command
+
+import (
+	"strings"
+
+	"github.com/mitchellh/cli"
+)
+
+type ConfigCommand struct {
+	Meta
+}
+
+func (f *ConfigCommand) Help() string {
+	helpText := `
+Usage: nomad config <subcommand> [options] [args]
+
+  This command groups subcommands for interacting with configurations.
+  Users can validate configurations for the Nomad agent.
+
+  Validate configuration:
+
+      $ nomad config validate <config_path> [<config_path>...]
+
+  Please see the individual subcommand help for detailed usage information.
+`
+
+	return strings.TrimSpace(helpText)
+}
+
+func (f *ConfigCommand) Synopsis() string {
+	return "Interact with configurations"
+}
+
+func (f *ConfigCommand) Name() string { return "config" }
+
+func (f *ConfigCommand) Run(args []string) int {
+	return cli.RunResultHelp
+}

command/config_validate.go

@@ -0,0 +1,89 @@
+package command
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+
+	multierror "github.com/hashicorp/go-multierror"
+	agent "github.com/hashicorp/nomad/command/agent"
+)
+
+type ConfigValidateCommand struct {
+	Meta
+}
+
+func (c *ConfigValidateCommand) Help() string {
+	helpText := `
+Usage: nomad config validate <config_path> [<config_path...>]
+
+  Perform validation on a set of Nomad configuration files. This is useful
+  to test the Nomad configuration without starting the agent.
+
+  Accepts the path to either a single config file or a directory of
+  config files to use for configuring the Nomad agent. This option may
+  be specified multiple times. If multiple config files are used, the
+  values from each will be merged together. During merging, values from
+  files found later in the list are merged over values from previously
+  parsed files.
+
+  This command cannot operate on partial configuration fragments since
+  those won't pass the full agent validation. This command does not
+  require an ACL token.
+
+  Returns 0 if the configuration is valid, or 1 if there are problems.
+`
+
+	return strings.TrimSpace(helpText)
+}
+
+func (c *ConfigValidateCommand) Synopsis() string {
+	return "Validate config files/directories"
+}
+
+func (c *ConfigValidateCommand) Name() string { return "config validate" }
+
+func (c *ConfigValidateCommand) Run(args []string) int {
+	var mErr multierror.Error
+	flags := c.Meta.FlagSet(c.Name(), FlagSetClient)
+	flags.Usage = func() { c.Ui.Output(c.Help()) }
+	if err := flags.Parse(args); err != nil {
+		c.Ui.Error(err.Error())
+		return 1
+	}
+
+	configPath := flags.Args()
+	if len(configPath) < 1 {
+		c.Ui.Error("Must specify at least one config file or directory")
+		return 1
+	}
+
+	config := agent.DefaultConfig()
+
+	for _, path := range configPath {
+		fc, err := agent.LoadConfig(path)
+		if err != nil {
+			multierror.Append(&mErr, fmt.Errorf(
+				"Error loading configuration from %s: %s", path, err))
+			continue
+		}
+		if fc == nil || reflect.DeepEqual(fc, &agent.Config{}) {
+			c.Ui.Warn(fmt.Sprintf("No configuration loaded from %s", path))
+		}
+
+		config = config.Merge(fc)
+	}
+	if err := mErr.ErrorOrNil(); err != nil {
+		c.Ui.Error(err.Error())
+		return 1
+	}
+	cmd := agent.Command{Ui: c.Ui}
+	valid := cmd.IsValidConfig(config, agent.DefaultConfig())
+	if !valid {
+		c.Ui.Error("Configuration is invalid")
+		return 1
+	}
+
+	c.Ui.Output("Configuration is valid!")
+	return 0
+}

command/config_validate_test.go

@@ -0,0 +1,106 @@
+package command
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/mitchellh/cli"
+)
+
+func TestConfigValidateCommand_FailWithEmptyDir(t *testing.T) {
+	t.Parallel()
+	fh, err := ioutil.TempDir("", "nomad")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	defer os.Remove(fh)
+
+	ui := cli.NewMockUi()
+	cmd := &ConfigValidateCommand{Meta: Meta{Ui: ui}}
+	args := []string{fh}
+
+	code := cmd.Run(args)
+	if code != 1 {
+		t.Fatalf("expected exit 1, actual: %d", code)
+	}
+}
+
+func TestConfigValidateCommand_SucceedWithMinimalConfigFile(t *testing.T) {
+	t.Parallel()
+	fh, err := ioutil.TempDir("", "nomad")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	defer os.Remove(fh)
+
+	fp := filepath.Join(fh, "config.hcl")
+	err = ioutil.WriteFile(fp, []byte(`data_dir="/"
+	client {
+		enabled = true
+	}`), 0644)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	ui := cli.NewMockUi()
+	cmd := &ConfigValidateCommand{Meta: Meta{Ui: ui}}
+	args := []string{fh}
+
+	code := cmd.Run(args)
+	if code != 0 {
+		t.Fatalf("expected exit 0, actual: %d", code)
+	}
+}
+
+func TestConfigValidateCommand_FailOnParseBadConfigFile(t *testing.T) {
+	t.Parallel()
+	fh, err := ioutil.TempDir("", "nomad")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	defer os.Remove(fh)
+
+	fp := filepath.Join(fh, "config.hcl")
+	err = ioutil.WriteFile(fp, []byte(`a: b`), 0644)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	ui := cli.NewMockUi()
+	cmd := &ConfigValidateCommand{Meta: Meta{Ui: ui}}
+	args := []string{fh}
+
+	code := cmd.Run(args)
+	if code != 1 {
+		t.Fatalf("expected exit 1, actual: %d", code)
+	}
+}
+
+func TestConfigValidateCommand_FailOnValidateParsableConfigFile(t *testing.T) {
+	t.Parallel()
+	fh, err := ioutil.TempDir("", "nomad")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	defer os.Remove(fh)
+
+	fp := filepath.Join(fh, "config.hcl")
+	err = ioutil.WriteFile(fp, []byte(`data_dir="../"
+	client {
+		enabled = true
+	}`), 0644)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	ui := cli.NewMockUi()
+	cmd := &ConfigValidateCommand{Meta: Meta{Ui: ui}}
+	args := []string{fh}
+
+	code := cmd.Run(args)
+	if code != 1 {
+		t.Fatalf("expected exit 1, actual: %d", code)
+	}
+}