Add error statements to inspect and config library (#4074)

* add error statements to inspect and config library

* remove ioutil function

* remove comment

---------

Co-authored-by: Pierre HILBERT <[email protected]>

changelog/fragments/1704994055-add-error-statements.yaml

@@ -0,0 +1,32 @@
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: enhancement
+
+# Change summary; a 80ish characters long description of the change.
+summary: add error descriptors to inspect command, config methods
+
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# NOTE: This field will be rendered only for breaking-change and known-issue kinds at the moment.
+#description:
+
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: config
+
+# PR URL; optional; the PR number that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+#pr: https://github.com/owner/repo/1234
+
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+#issue: https://github.com/owner/repo/1234

internal/pkg/agent/cmd/inspect.go

@@ -130,20 +130,23 @@ type inspectConfigOpts struct {
 func inspectConfig(ctx context.Context, cfgPath string, opts inspectConfigOpts, streams *cli.IOStreams) error {
 	l, err := newErrorLogger()
 	if err != nil {
-		return err
+		return fmt.Errorf("error creating logger: %w", err)
 	}
 
 	if !opts.variables && !opts.includeMonitoring {
 		fullCfg, err := operations.LoadFullAgentConfig(ctx, l, cfgPath, true)
 		if err != nil {
-			return err
+			return fmt.Errorf("error loading agent config: %w", err)
+		}
+		err = printConfig(fullCfg, streams)
+		if err != nil {
+			return fmt.Errorf("error printing config: %w", err)
 		}
-		return printConfig(fullCfg, streams)
 	}
 
 	cfg, lvl, err := getConfigWithVariables(ctx, l, cfgPath, opts.variablesWait)
 	if err != nil {
-		return err
+		return fmt.Errorf("error fetching config with variables: %w", err)
 	}
 
 	agentInfo, err := info.NewAgentInfoWithLog(ctx, "error", false)
@@ -212,12 +215,17 @@ func printMapStringConfig(mapStr map[string]interface{}, streams *cli.IOStreams)
 	return err
 }
 
+// convert the config object to a mapstr and print to the stream specified in in streams.Out
 func printConfig(cfg *config.Config, streams *cli.IOStreams) error {
 	mapStr, err := cfg.ToMapStr()
 	if err != nil {
-		return err
+		return fmt.Errorf("error parsing config as hashmap: %w", err)
+	}
+	err = printMapStringConfig(mapStr, streams)
+	if err != nil {
+		return fmt.Errorf("error printing config to output: %w", err)
 	}
-	return printMapStringConfig(mapStr, streams)
+	return nil
 }
 
 type inspectComponentsOpts struct {

internal/pkg/config/config.go

@@ -155,7 +155,7 @@ func (c *Config) ToMapStr(opts ...interface{}) (map[string]interface{}, error) {
 	}
 	ucfgOpts, local, err := getOptions(opts...)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error unpacking logs: %w", err)
 	}
 
 	// remove and unpack each skip keys into its own map with no resolve
@@ -166,29 +166,29 @@ func (c *Config) ToMapStr(opts ...interface{}) (map[string]interface{}, error) {
 		if c.access().HasField(skip) {
 			subCfg, err := c.access().Child(skip, -1)
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("error accessing skip key %s: %w", skip, err)
 			}
 			var subUnpacked interface{}
 			if subCfg.IsDict() {
 				var subDict map[string]interface{}
 				err = subCfg.Unpack(&subDict, ucfg.ResolveNOOP)
 				if err != nil {
-					return nil, err
+					return nil, fmt.Errorf("error unpacking subdict object in config for skip key %s: %w", skip, err)
 				}
 				subUnpacked = subDict
 			} else if subCfg.IsArray() {
 				var subArr []interface{}
 				err = subCfg.Unpack(&subArr, ucfg.ResolveNOOP)
 				if err != nil {
-					return nil, err
+					return nil, fmt.Errorf("error unpacking subarray in config for skip key %s: %w ", skip, err)
 				}
 				subUnpacked = subArr
 			} else {
 				return nil, fmt.Errorf("unsupported type for SkipKeys option %s", skip)
 			}
 			_, err = c.access().Remove(skip, -1)
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("error removing skip key %s: %w", skip, err)
 			}
 			skippedKeys[skip] = subUnpacked
 			skippedKeysOrig[skip] = subCfg
@@ -198,7 +198,7 @@ func (c *Config) ToMapStr(opts ...interface{}) (map[string]interface{}, error) {
 	// perform unpack with the skip keys removed
 	var m map[string]interface{}
 	if err := c.access().Unpack(&m, ucfgOpts...); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error unpacking config to MapStr object: %w", err)
 	}
 
 	// add the skipped keys into the map and back into the config
@@ -208,7 +208,7 @@ func (c *Config) ToMapStr(opts ...interface{}) (map[string]interface{}, error) {
 	if len(skippedKeysOrig) > 0 {
 		err := c.access().Merge(skippedKeysOrig, ucfg.ResolveNOOP)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("error merging config with skipped key config: %w", err)
 		}
 	}
 	return m, nil

internal/pkg/config/operations/inspector.go

@@ -29,12 +29,12 @@ var (
 func LoadFullAgentConfig(ctx context.Context, logger *logger.Logger, cfgPath string, failOnFleetMissing bool) (*config.Config, error) {
 	rawConfig, err := loadConfig(ctx, cfgPath)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error loading raw config: %w", err)
 	}
 
 	cfg, err := configuration.NewFromConfig(rawConfig)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error creating config object from raw agent config: %w", err)
 	}
 
 	if configuration.IsStandalone(cfg.Fleet) {
@@ -57,7 +57,7 @@ func LoadFullAgentConfig(ctx context.Context, logger *logger.Logger, cfgPath str
 
 	fleetConfig, err := loadFleetConfig(ctx, logger)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error obtaining fleet config: %w", err)
 	} else if fleetConfig == nil {
 		if failOnFleetMissing {
 			return nil, ErrNoFleetConfig
@@ -78,7 +78,7 @@ func LoadFullAgentConfig(ctx context.Context, logger *logger.Logger, cfgPath str
 func loadConfig(ctx context.Context, configPath string) (*config.Config, error) {
 	rawConfig, err := config.LoadFile(configPath)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error loading config file %s: %w", configPath, err)
 	}
 
 	path := paths.AgentConfigFile()
@@ -100,10 +100,13 @@ func loadConfig(ctx context.Context, configPath string) (*config.Config, error)
 	}
 
 	// merge local configuration and configuration persisted from fleet.
-	_ = rawConfig.Merge(config)
+	err = rawConfig.Merge(config)
+	if err != nil {
+		return nil, fmt.Errorf("error merging local and fleet config: %w", err)
+	}
 
 	if err := info.InjectAgentConfig(rawConfig); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error injecting agent config: %w", err)
 	}
 
 	return rawConfig, nil