Revise the print-config command (#13679)

#### Description

See #12369, #11775.

Fixes #13278.

cc/ @VihasMakwana 

This refines the print-config command with two modes, "redacted" and
"unredacted", with an optional "--validate" or no, with optional
--format=yaml or json.

#### Link to tracking issue
Fixes #11775.

#### Testing

✔️ 

#### Documentation

✔️

---------

Co-authored-by: Alex Boten <[email protected]>
Co-authored-by: Evan Bradley <[email protected]>
Co-authored-by: Pablo Baeyens <[email protected]>

Author: 4 people

.chloggen/print-config-redaction.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: all
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add unified print-config command with mode support (redacted, unredacted), json support (unstable), and validation support.
+
+# One or more tracking issues or pull requests related to the change
+issues: [11775]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: This replaces the `print-initial-config` command. See the `service` package README for more details. The original command name `print-initial-config` remains an alias, to be retired with the feature flag.
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

.github/workflows/utils/cspell.json

@@ -478,6 +478,7 @@
       "unmarshal",
       "unmarshalling",
       "unmarshalls",
+      "unredacted",
       "unshallow",
       "unstarted",
       "userfriendly",

cmd/mdatagen/go.mod

@@ -184,8 +184,6 @@ replace go.opentelemetry.io/collector/extension/extensionauth => ../../extension
 
 replace go.opentelemetry.io/collector/service/hostcapabilities => ../../service/hostcapabilities
 
-replace go.opentelemetry.io/collector/confmap/provider/yamlprovider => ../../confmap/provider/yamlprovider
-
 replace go.opentelemetry.io/collector/config/configtls => ../../config/configtls
 
 replace go.opentelemetry.io/collector/config/configcompression => ../../config/configcompression

otelcol/collector.go

@@ -55,6 +55,8 @@ func (s State) String() string {
 // CollectorSettings holds configuration for creating a new Collector.
 type CollectorSettings struct {
 	// Factories service factories.
+	// TODO(13263) This is a dangerous "bare" function value, should define an interface
+	// following style guidelines.
 	Factories func() (Factories, error)
 
 	// BuildInfo provides collector start information.

otelcol/command_print.go

@@ -4,55 +4,196 @@
 package otelcol // import "go.opentelemetry.io/collector/otelcol"
 
 import (
+	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
+	"io"
+	"strings"
 
 	"github.com/spf13/cobra"
 	yaml "go.yaml.in/yaml/v3"
 
 	"go.opentelemetry.io/collector/confmap"
+	"go.opentelemetry.io/collector/confmap/xconfmap"
 	"go.opentelemetry.io/collector/featuregate"
 )
 
+const featureGateName = "otelcol.printInitialConfig"
+
 var printCommandFeatureFlag = featuregate.GlobalRegistry().MustRegister(
-	"otelcol.printInitialConfig",
+	featureGateName,
 	featuregate.StageAlpha,
 	featuregate.WithRegisterFromVersion("v0.120.0"),
-	featuregate.WithRegisterDescription("if set to true, turns on the print-initial-config command"),
+	featuregate.WithRegisterDescription("if set to true, enable the print-config command"),
 )
 
-// newConfigPrintSubCommand constructs a new config print sub command using the given CollectorSettings.
+// newConfigPrintSubCommand constructs a new print-config command using the given CollectorSettings.
 func newConfigPrintSubCommand(set CollectorSettings, flagSet *flag.FlagSet) *cobra.Command {
+	var outputFormat string
+	var mode string
+	var validate bool
+
 	cmd := &cobra.Command{
-		Use:   "print-initial-config",
-		Short: "Prints the Collector's configuration in YAML format after all config sources are resolved and merged",
-		Long:  `Note: This command prints the final yaml configuration before it is unmarshaled into config structs, which may contain sensitive values.`,
-		Args:  cobra.ExactArgs(0),
+		Use:     "print-config",
+		Aliases: []string{"print-initial-config"},
+		Short:   "Prints the Collector's configuration in the specified mode",
+		Long: `Prints the Collector's configuration with different levels of processing:
+
+- redacted: Shows the resolved configuration with sensitive data redacted (default)
+- unredacted: Shows the resolved configuration with all sensitive data visible
+
+The output prints in YAML by default. To print JSON use --format=json,
+however this is considered unstable.
+
+Validation is enabled by default, as a safety measure.
+
+All modes are experimental, requiring the otelcol.printInitialConfig feature gate.`,
+		Args: cobra.ExactArgs(0),
 		RunE: func(cmd *cobra.Command, _ []string) error {
-			if !printCommandFeatureFlag.IsEnabled() {
-				return errors.New("print-initial-config is currently experimental, use the otelcol.printInitialConfig feature gate to enable this command")
-			}
-			err := updateSettingsUsingFlags(&set, flagSet)
-			if err != nil {
-				return err
+			pc := printContext{
+				cmd:          cmd,
+				stdout:       cmd.OutOrStdout(),
+				set:          set,
+				outputFormat: outputFormat,
+				validate:     validate,
 			}
-			resolver, err := confmap.NewResolver(set.ConfigProviderSettings.ResolverSettings)
-			if err != nil {
-				return fmt.Errorf("failed to create new resolver: %w", err)
-			}
-			conf, err := resolver.Resolve(cmd.Context())
-			if err != nil {
-				return fmt.Errorf("error while resolving config: %w", err)
-			}
-			b, err := yaml.Marshal(conf.ToStringMap())
-			if err != nil {
-				return fmt.Errorf("error while marshaling to YAML: %w", err)
-			}
-			fmt.Printf("%s\n", b)
-			return nil
+			return pc.configPrintSubCommand(flagSet, mode)
 		},
 	}
+
+	formatHelp := "Output format: yaml (default), json (unstable))"
+	cmd.Flags().StringVar(&outputFormat, "format", "yaml", formatHelp)
+
+	modeHelp := "Operating mode: redacted (default), unredacted"
+	cmd.Flags().StringVar(&mode, "mode", "redacted", modeHelp)
+
+	validateHelp := "Validation mode: true (default), false"
+	cmd.Flags().BoolVar(&validate, "validate", true, validateHelp)
+
 	cmd.Flags().AddGoFlagSet(flagSet)
 	return cmd
 }
+
+type printContext struct {
+	cmd          *cobra.Command
+	stdout       io.Writer
+	set          CollectorSettings
+	outputFormat string
+	validate     bool
+}
+
+func (pctx *printContext) configPrintSubCommand(flagSet *flag.FlagSet, mode string) error {
+	if !printCommandFeatureFlag.IsEnabled() {
+		return errors.New("print-config is currently experimental, use the otelcol.printInitialConfig feature gate to enable this command")
+	}
+	err := updateSettingsUsingFlags(&pctx.set, flagSet)
+	if err != nil {
+		return err
+	}
+
+	switch strings.ToLower(mode) {
+	case "redacted":
+		return pctx.printRedactedConfig()
+	case "unredacted":
+		return pctx.printUnredactedConfig()
+	default:
+		return fmt.Errorf("invalid mode %q: modes are: redacted, unredacted", mode)
+	}
+}
+
+// printConfigData formats and prints configuration data in yaml or json format.
+func (pctx *printContext) printConfigData(data map[string]any) error {
+	format := pctx.outputFormat
+	if format == "" {
+		format = "yaml"
+	}
+
+	switch {
+	case strings.EqualFold(format, "yaml"):
+		b, err := yaml.Marshal(data)
+		if err != nil {
+			return err
+		}
+		fmt.Fprintf(pctx.stdout, "%s\n", b)
+		return nil
+
+	case strings.EqualFold(format, "json"):
+		encoder := json.NewEncoder(pctx.stdout)
+		encoder.SetIndent("", "  ")
+		return encoder.Encode(data)
+	}
+
+	return fmt.Errorf("unrecognized print format: %s", format)
+}
+
+func (pctx *printContext) getPrintableConfig() (any, error) {
+	var factories Factories
+	if pctx.set.Factories != nil {
+		var err error
+		factories, err = pctx.set.Factories()
+		if err != nil {
+			return nil, fmt.Errorf("failed to get factories: %w", err)
+		}
+	}
+
+	configProvider, err := NewConfigProvider(pctx.set.ConfigProviderSettings)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create config provider: %w", err)
+	}
+
+	cfg, err := configProvider.Get(pctx.cmd.Context(), factories)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get config: %w", err)
+	}
+	return cfg, nil
+}
+
+// printUnredactedConfig prints resolved configuration before interpreting
+// with the intended types for each component, thus it shows the full
+// configuration without considering configuopaque. Use with caution.
+func (pctx *printContext) printUnredactedConfig() error {
+	if pctx.validate {
+		// Validation serves prevent revealing invalid data.
+		cfg, err := pctx.getPrintableConfig()
+		if err != nil {
+			return err
+		}
+		if err = xconfmap.Validate(cfg); err != nil {
+			return fmt.Errorf("invalid configuration: %w", err)
+		}
+
+		// Note: we discard the validated configuration.
+	}
+	resolver, err := confmap.NewResolver(pctx.set.ConfigProviderSettings.ResolverSettings)
+	if err != nil {
+		return fmt.Errorf("failed to create new resolver: %w", err)
+	}
+	conf, err := resolver.Resolve(pctx.cmd.Context())
+	if err != nil {
+		return fmt.Errorf("error while resolving config: %w", err)
+	}
+	return pctx.printConfigData(conf.ToStringMap())
+}
+
+// printRedactedConfig prints resolved configuration with its assigned
+// types, but without validation. Notably, configopaque strings are printed
+// as "[redacted]". This is the default.
+func (pctx *printContext) printRedactedConfig() error {
+	cfg, err := pctx.getPrintableConfig()
+	if err != nil {
+		return err
+	}
+
+	if pctx.validate {
+		if err = xconfmap.Validate(cfg); err != nil {
+			return fmt.Errorf("invalid configuration: %w", err)
+		}
+	}
+
+	confMap := confmap.New()
+	if err := confMap.Marshal(cfg); err != nil {
+		return fmt.Errorf("failed to marshal config: %w", err)
+	}
+	return pctx.printConfigData(confMap.ToStringMap())
+}