Handle PRIVILEGE_LEVEL_CHANGE action

changelog/fragments/1759318728-support-for-privilege_level_change.yaml

@@ -0,0 +1,45 @@
+# REQUIRED
+# 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: feature
+
+# REQUIRED for all kinds
+# Change summary; a 80ish characters long description of the change.
+summary: support for privilege_level_change
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# description: 
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# impact:
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# action:
+
+# REQUIRED for all kinds
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: elastic-agent
+
+# AUTOMATED
+# OPTIONAL to manually add other PR URLs
+# PR URL: A link the PR 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
+
+# AUTOMATED
+# OPTIONAL to manually add other issue URLs
+# 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/actions/handlers/handle_action_privilege_level_change.go

@@ -0,0 +1,136 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License 2.0;
+// you may not use this file except in compliance with the Elastic License 2.0.
+
+package handlers
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/elastic/elastic-agent/internal/pkg/agent/application/coordinator"
+	"github.com/elastic/elastic-agent/internal/pkg/agent/application/paths"
+	"github.com/elastic/elastic-agent/internal/pkg/agent/application/reexec"
+	"github.com/elastic/elastic-agent/internal/pkg/agent/install"
+	"github.com/elastic/elastic-agent/internal/pkg/agent/install/service"
+	"github.com/elastic/elastic-agent/internal/pkg/config"
+	"github.com/elastic/elastic-agent/internal/pkg/fleetapi"
+	"github.com/elastic/elastic-agent/internal/pkg/fleetapi/acker"
+	"github.com/elastic/elastic-agent/pkg/core/logger"
+)
+
+type reexecCoordinator interface {
+	ReExec(callback reexec.ShutdownCallbackFn, argOverrides ...string)
+}
+
+type PrivilegeLevelChange struct {
+	log   *logger.Logger
+	coord reexecCoordinator
+	ch    chan coordinator.ConfigChange
+}
+
+func NewPrivilegeLevelChange(
+	log *logger.Logger,
+	coord reexecCoordinator,
+	ch chan coordinator.ConfigChange,
+) *PrivilegeLevelChange {
+	return &PrivilegeLevelChange{
+		log:   log,
+		coord: coord,
+		ch:    ch,
+	}
+}
+
+// Handle handles UNENROLL action.
+func (h *PrivilegeLevelChange) Handle(ctx context.Context, a fleetapi.Action, acker acker.Acker) error {
+	return h.handle(ctx, a, acker)
+}
+
+func (h *PrivilegeLevelChange) handle(ctx context.Context, a fleetapi.Action, acker acker.Acker) (rerr error) {
+	action, ok := a.(*fleetapi.ActionPrivilegeLevelChange)
+	if !ok {
+		return fmt.Errorf("invalid type, expected ActionPrivilegeLevelChange and received %T", a)
+	}
+
+	defer func() {
+		if rerr != nil {
+			h.ackFailure(ctx, rerr, action, acker)
+		}
+	}()
+
+	if !action.Data.Unprivileged {
+		// only unprivileged supported at this point
+		return fmt.Errorf("unsupported action, ActionPrivilegeLevelChange supports only downgrading permissions")
+	}
+
+	// ensure no component issues
+	err := service.EnsureNoServiceComponentIssues()
+	if err != nil {
+		h.log.Debugf("handlerPrivilegeLevelChange: found issues with components: %v", err)
+		return err
+	}
+
+	var username, groupname, password string
+	if action.Data.UserInfo != nil {
+		username = action.Data.UserInfo.Username
+		groupname = action.Data.UserInfo.Groupname
+		password = action.Data.UserInfo.Password
+	}
+	username, password = install.UnprivilegedUser(username, password)
+	groupname = install.UnprivilegedGroup(groupname)
+
+	// apply empty config to stop processing
+	unenrollPolicy := newPolicyChange(ctx, config.New(), a, acker, true, false)
+	h.ch <- unenrollPolicy
+
+	unenrollCtx, cancel := context.WithTimeout(ctx, unenrollTimeout)
+	defer cancel()
+
+	unenrollPolicy.WaitAck(unenrollCtx)
+
+	// fix permissions
+	topPath := paths.Top()
+	_, err = install.SwitchServiceUser(topPath, &debugDescriber{h.log}, username, groupname, password)
+	if err != nil {
+		// error already adds context
+		return err
+	}
+
+	// ack
+	if err := acker.Ack(ctx, a); err != nil {
+		h.log.Errorw("failed to ACK an action",
+			"error.message", err)
+	}
+	if err := acker.Commit(ctx); err != nil {
+		h.log.Errorw("failed to commit ACK of an action",
+			"error.message", err)
+	}
+
+	// restart
+	h.coord.ReExec(nil)
+	return nil
+}
+
+func (h *PrivilegeLevelChange) ackFailure(ctx context.Context, err error, action *fleetapi.ActionPrivilegeLevelChange, acker acker.Acker) {
+	action.Err = err
+
+	if err := acker.Ack(ctx, action); err != nil {
+		h.log.Errorw("failed to ack privilege level change action",
+			"error.message", err,
+			"action", action)
+	}
+
+	if err := acker.Commit(ctx); err != nil {
+		h.log.Errorw("failed to commit privilege level change action",
+			"error.message", err,
+			"action", action)
+	}
+}
+
+type debugDescriber struct {
+	l *logger.Logger
+}
+
+func (d *debugDescriber) Describe(a string) {
+	d.l.Debug(a)
+}

internal/pkg/agent/application/managed_mode.go

@@ -402,6 +402,11 @@ func (m *managedConfigManager) initDispatcher(canceller context.CancelFunc) *han
 		handlers.NewMigrate(m.log, m.agentInfo, m.coord),
 	)
 
+	m.dispatcher.MustRegister(
+		&fleetapi.ActionPrivilegeLevelChange{},
+		handlers.NewPrivilegeLevelChange(m.log, m.coord, m.ch),
+	)
+
 	m.dispatcher.MustRegister(
 		&fleetapi.ActionUnknown{},
 		handlers.NewUnknown(m.log),

internal/pkg/agent/cmd/inspect.go

@@ -12,27 +12,20 @@ import (
 	"time"
 
 	"github.com/spf13/cobra"
-	"go.opentelemetry.io/collector/confmap"
 	"gopkg.in/yaml.v2"
 
-	componentmonitoring "github.com/elastic/elastic-agent/internal/pkg/agent/application/monitoring/component"
-
 	"github.com/elastic/elastic-agent-libs/logp"
 	"github.com/elastic/elastic-agent-libs/service"
 
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/info"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/paths"
-	"github.com/elastic/elastic-agent/internal/pkg/agent/configuration"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/errors"
-	"github.com/elastic/elastic-agent/internal/pkg/agent/transpiler"
-	"github.com/elastic/elastic-agent/internal/pkg/agent/vars"
+	installSvc "github.com/elastic/elastic-agent/internal/pkg/agent/install/service"
 	"github.com/elastic/elastic-agent/internal/pkg/capabilities"
 	"github.com/elastic/elastic-agent/internal/pkg/cli"
 	"github.com/elastic/elastic-agent/internal/pkg/config"
 	"github.com/elastic/elastic-agent/internal/pkg/config/operations"
 	"github.com/elastic/elastic-agent/internal/pkg/diagnostics"
-	otelconfig "github.com/elastic/elastic-agent/internal/pkg/otel/config"
-	"github.com/elastic/elastic-agent/internal/pkg/otel/manager"
 	"github.com/elastic/elastic-agent/pkg/component"
 	"github.com/elastic/elastic-agent/pkg/core/logger"
 	"github.com/elastic/elastic-agent/pkg/utils"
@@ -161,7 +154,7 @@ func inspectConfig(ctx context.Context, cfgPath string, opts inspectConfigOpts,
 		return nil
 	}
 
-	cfg, otel, lvl, err := getConfigWithVariables(ctx, l, cfgPath, opts.variablesWait, !isAdmin)
+	cfg, otel, lvl, err := installSvc.GetConfigWithVariables(ctx, l, cfgPath, opts.variablesWait, !isAdmin)
 	if err != nil {
 		return fmt.Errorf("error fetching config with variables: %w", err)
 	}
@@ -183,7 +176,7 @@ func inspectConfig(ctx context.Context, cfgPath string, opts inspectConfigOpts,
 			return fmt.Errorf("failed to detect inputs and outputs: %w", err)
 		}
 
-		monitorFn, err := getMonitoringFn(ctx, l, cfg, otel)
+		monitorFn, err := installSvc.GetMonitoringFn(ctx, l, cfg, otel)
 		if err != nil {
 			return fmt.Errorf("failed to get monitoring: %w", err)
 		}
@@ -291,7 +284,7 @@ func inspectComponents(ctx context.Context, cfgPath string, opts inspectComponen
 		return err
 	}
 
-	comps, err := getComponentsFromPolicy(ctx, l, cfgPath, opts.variablesWait)
+	comps, err := installSvc.GetComponentsFromPolicy(ctx, l, cfgPath, opts.variablesWait)
 	if err != nil {
 		// error already includes the context
 		return err
@@ -356,126 +349,6 @@ func inspectComponents(ctx context.Context, cfgPath string, opts inspectComponen
 	return printComponents(allowed, blocked, streams)
 }
 
-func getComponentsFromPolicy(ctx context.Context, l *logger.Logger, cfgPath string, variablesWait time.Duration, platformModifiers ...component.PlatformModifier) ([]component.Component, error) {
-	// Load the requirements before trying to load the configuration. These should always load
-	// even if the configuration is wrong.
-	platform, err := component.LoadPlatformDetail(platformModifiers...)
-	if err != nil {
-		return nil, fmt.Errorf("failed to gather system information: %w", err)
-	}
-	specs, err := component.LoadRuntimeSpecs(paths.Components(), platform)
-	if err != nil {
-		return nil, fmt.Errorf("failed to detect inputs and outputs: %w", err)
-	}
-
-	isAdmin, err := utils.HasRoot()
-	if err != nil {
-		return nil, fmt.Errorf("error checking for root/Administrator privileges: %w", err)
-	}
-
-	m, otel, lvl, err := getConfigWithVariables(ctx, l, cfgPath, variablesWait, !isAdmin)
-	if err != nil {
-		return nil, err
-	}
-
-	monitorFn, err := getMonitoringFn(ctx, l, m, otel)
-	if err != nil {
-		return nil, fmt.Errorf("failed to get monitoring: %w", err)
-	}
-
-	agentInfo, err := info.NewAgentInfoWithLog(ctx, "error", false)
-	if err != nil {
-		return nil, fmt.Errorf("could not load agent info: %w", err)
-	}
-
-	// Compute the components from the computed configuration.
-	comps, err := specs.ToComponents(m, monitorFn, lvl, agentInfo, map[string]uint64{})
-	if err != nil {
-		return nil, fmt.Errorf("failed to render components: %w", err)
-	}
-
-	return comps, nil
-}
-
-func getMonitoringFn(ctx context.Context, logger *logger.Logger, cfg map[string]interface{}, otelCfg *confmap.Conf) (component.GenerateMonitoringCfgFn, error) {
-	config, err := config.NewConfigFrom(cfg)
-	if err != nil {
-		return nil, err
-	}
-
-	agentCfg := configuration.DefaultConfiguration()
-	if err := config.UnpackTo(agentCfg); err != nil {
-		return nil, err
-	}
-
-	agentInfo, err := info.NewAgentInfoWithLog(ctx, "error", false)
-	if err != nil {
-		return nil, fmt.Errorf("could not load agent info: %w", err)
-	}
-	otelExecMode := otelconfig.GetExecutionModeFromConfig(logger, config)
-	isOtelExecModeSubprocess := otelExecMode == manager.SubprocessExecutionMode
-	monitor := componentmonitoring.New(agentCfg.Settings.V1MonitoringEnabled, agentCfg.Settings.DownloadConfig.OS(), agentCfg.Settings.MonitoringConfig, otelCfg, agentInfo, isOtelExecModeSubprocess)
-	return monitor.MonitoringConfig, nil
-}
-
-func getConfigWithVariables(ctx context.Context, l *logger.Logger, cfgPath string, timeout time.Duration, unprivileged bool) (map[string]interface{}, *confmap.Conf, logp.Level, error) {
-
-	cfg, err := operations.LoadFullAgentConfig(ctx, l, cfgPath, true, unprivileged)
-	if err != nil {
-		return nil, nil, logp.InfoLevel, err
-	}
-	lvl, err := getLogLevel(cfg, cfgPath)
-	if err != nil {
-		return nil, nil, logp.InfoLevel, err
-	}
-	m, err := cfg.ToMapStr()
-	if err != nil {
-		return nil, nil, lvl, err
-	}
-	ast, err := transpiler.NewAST(m)
-	if err != nil {
-		return nil, nil, lvl, fmt.Errorf("could not create the AST from the configuration: %w", err)
-	}
-
-	// Wait for the variables based on the timeout.
-	vars, err := vars.WaitForVariables(ctx, l, cfg, timeout)
-	if err != nil {
-		return nil, nil, lvl, fmt.Errorf("failed to gather variables: %w", err)
-	}
-
-	// Render the inputs using the discovered inputs.
-	inputs, ok := transpiler.Lookup(ast, "inputs")
-	if ok {
-		renderedInputs, err := transpiler.RenderInputs(inputs, vars)
-		if err != nil {
-			return nil, nil, lvl, fmt.Errorf("rendering inputs failed: %w", err)
-		}
-		err = transpiler.Insert(ast, renderedInputs, "inputs")
-		if err != nil {
-			return nil, nil, lvl, fmt.Errorf("inserting rendered inputs failed: %w", err)
-		}
-	}
-	m, err = ast.Map()
-	if err != nil {
-		return nil, nil, lvl, fmt.Errorf("failed to convert ast to map[string]interface{}: %w", err)
-	}
-	return m, cfg.OTel, lvl, nil
-}
-
-func getLogLevel(rawCfg *config.Config, cfgPath string) (logp.Level, error) {
-	cfg, err := configuration.NewFromConfig(rawCfg)
-	if err != nil {
-		return logger.DefaultLogLevel, errors.New(err,
-			fmt.Sprintf("could not parse configuration file %s", cfgPath),
-			errors.TypeFilesystem,
-			errors.M(errors.MetaKeyPath, cfgPath))
-	}
-	if cfg.Settings.LoggingConfig != nil {
-		return cfg.Settings.LoggingConfig.Level, nil
-	}
-	return logger.DefaultLogLevel, nil
-}
-
 func printComponents(
 	components []component.Component,
 	blocked []component.Component,