Prevent leaking secrets when logging component model (#6329)

* feat: Prevent leaking secrets when logging component model

* add changelog entry

* test: add test checking that secrets are not leaked when components are marhsaled to JSON

changelog/fragments/1734098868-prevent-leaking-secrets-when-logging-component-model.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: Prevent leaking secrets when logging the component model
+
+# 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: elastic-agent
+
+# 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/application/coordinator/coordinator.go

@@ -1400,6 +1400,7 @@ func (c *Coordinator) refreshComponentModel(ctx context.Context) (err error) {
 	}
 
 	c.logger.Info("Updating running component model")
+	c.logger.With("components", model.Components).Debug("Updating running component model")
 	c.runtimeMgr.Update(model)
 	return nil
 }

pkg/component/component.go

@@ -5,6 +5,7 @@
 package component
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"sort"
@@ -173,6 +174,39 @@ func (c Component) MarshalYAML() (interface{}, error) {
 	return c, nil
 }
 
+func (c *Component) MarshalJSON() ([]byte, error) {
+	marshalableComponent := struct {
+		ID         string `json:"ID"`
+		InputType  string `json:"InputType"`
+		OutputType string `json:"OutputType"`
+		ErrMsg     string `json:"ErrMsg,omitempty"`
+		Units      []struct {
+			ID     string `json:"ID"`
+			ErrMsg string `json:"ErrMsg,omitempty"`
+		} `json:"Units"`
+	}{
+		ID:         c.ID,
+		InputType:  c.InputType,
+		OutputType: c.OutputType,
+	}
+	if c.Err != nil {
+		marshalableComponent.ErrMsg = c.Err.Error()
+	}
+	for i := range c.Units {
+		marshalableComponent.Units = append(marshalableComponent.Units, struct {
+			ID     string `json:"ID"`
+			ErrMsg string `json:"ErrMsg,omitempty"`
+		}{
+			ID: c.Units[i].ID,
+		})
+		if c.Units[i].Err != nil {
+			marshalableComponent.Units[i].ErrMsg = c.Units[i].Err.Error()
+		}
+	}
+
+	return json.Marshal(marshalableComponent)
+}
+
 // Type returns the type of the component.
 func (c *Component) Type() string {
 	if c.InputSpec != nil {

pkg/component/component_test.go

@@ -59,6 +59,32 @@ func TestComponentMarshalError(t *testing.T) {
 	require.Contains(t, string(outData), "test error value")
 }
 
+func TestMarshalJSON(t *testing.T) {
+	testComponent := Component{
+		ID:  "test-device",
+		Err: testErr{data: "test error value"},
+		Units: []Unit{
+			{
+				ID: "test-unit",
+				Config: &proto.UnitExpectedConfig{
+					Source: &structpb.Struct{
+						Fields: map[string]*structpb.Value{
+							"api_key": structpb.NewStringValue("test-api-key"),
+						},
+					},
+				},
+			},
+		},
+	}
+
+	marshaledBytes, err := testComponent.MarshalJSON()
+	require.NoError(t, err)
+	marshaledJsonString := string(marshaledBytes)
+	assert.Contains(t, marshaledJsonString, "test error value")
+	assert.Contains(t, marshaledJsonString, "test-unit")
+	assert.NotContains(t, marshaledJsonString, "test-api-key")
+}
+
 func TestToComponents(t *testing.T) {
 	linuxAMD64Platform := PlatformDetail{
 		Platform: Platform{