feat(nodeadm): add nodeadm config dump command

nodeadm/cmd/nodeadm/config/dump.go

@@ -0,0 +1,47 @@
+package config
+
+import (
+	"encoding/json"
+	"os"
+
+	"github.com/awslabs/amazon-eks-ami/nodeadm/internal/cli"
+	"github.com/awslabs/amazon-eks-ami/nodeadm/internal/configprovider"
+	"github.com/integrii/flaggy"
+	"go.uber.org/zap"
+)
+
+type dumpCmd struct {
+	cmd *flaggy.Subcommand
+}
+
+func NewDumpCommand() cli.Command {
+	cmd := flaggy.NewSubcommand("dump")
+	cmd.Description = "Dump configuration"
+	return &dumpCmd{
+		cmd: cmd,
+	}
+}
+
+func (c *dumpCmd) Flaggy() *flaggy.Subcommand {
+	return c.cmd
+}
+
+func (c *dumpCmd) Run(log *zap.Logger, opts *cli.GlobalOptions) error {
+	log.Info("Dumping configuration", zap.String("source", opts.ConfigSource))
+	provider, err := configprovider.BuildConfigProvider(opts.ConfigSource)
+	if err != nil {
+		return err
+	}
+	config, err := provider.Provide()
+	if err != nil {
+		return err
+	}
+
+	encoder := json.NewEncoder(os.Stdout)
+	encoder.SetIndent("", "  ")
+	if err = encoder.Encode(config); err != nil {
+		return err
+	}
+	log.Info("Configuration dumped")
+	return nil
+}

nodeadm/cmd/nodeadm/config/root.go

@@ -7,5 +7,6 @@ import (
 func NewConfigCommand() cli.Command {
 	container := cli.NewCommandContainer("config", "Manage configuration")
 	container.AddCommand(NewCheckCommand())
+	container.AddCommand(NewDumpCommand())
 	return container.AsCommand()
 }