[Elastic Agent] Fix status and inspect command to work inside running container (backport #25204)

x-pack/elastic-agent/CHANGELOG.next.asciidoc

@@ -53,6 +53,7 @@
 - Set --inscure in container when FLEET_SERVER_ENABLE and FLEET_INSECURE set {pull}25137[25137]
 - Restart process on output change {pull}24907[24907]
 - Fixed: limit for retries to Kibana configurable {issue}25063[25063]
+- Fix issue with status and inspect inside of container {pull}25204[25204]
 
 ==== New features
 

x-pack/elastic-agent/pkg/agent/cmd/container.go

@@ -25,6 +25,7 @@ import (
 	"github.com/elastic/beats/v7/x-pack/elastic-agent/pkg/agent/configuration"
 
 	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v2"
 
 	"github.com/elastic/beats/v7/libbeat/common/transport/tlscommon"
 	"github.com/elastic/beats/v7/libbeat/kibana"
@@ -164,7 +165,7 @@ func logContainerCmd(streams *cli.IOStreams, cmd *cobra.Command) error {
 
 func containerCmd(streams *cli.IOStreams, cmd *cobra.Command) error {
 	// set paths early so all action below use the defined paths
-	if err := setPaths(); err != nil {
+	if err := setPaths("", "", "", true); err != nil {
 		return err
 	}
 
@@ -635,13 +636,13 @@ func logToStderr(cfg *configuration.Configuration) {
 	}
 }
 
-func setPaths() error {
-	statePath := envWithDefault(defaultStateDirectory, "STATE_PATH")
+func setPaths(statePath, configPath, logsPath string, writePaths bool) error {
+	statePath = envWithDefault(statePath, "STATE_PATH")
 	if statePath == "" {
-		return errors.New("STATE_PATH cannot be set to an empty string")
+		statePath = defaultStateDirectory
 	}
 	topPath := filepath.Join(statePath, "data")
-	configPath := envWithDefault("", "CONFIG_PATH")
+	configPath = envWithDefault(configPath, "CONFIG_PATH")
 	if configPath == "" {
 		configPath = statePath
 	}
@@ -662,21 +663,75 @@ func setPaths() error {
 	if err := syncDir(srcDownloads, destDownloads); err != nil {
 		return fmt.Errorf("syncing download directory to STATE_PATH(%s) failed: %s", statePath, err)
 	}
+	originalTop := paths.Top()
 	paths.SetTop(topPath)
 	paths.SetConfig(configPath)
 	// when custom top path is provided the home directory is not versioned
 	paths.SetVersionHome(false)
 	// set LOGS_PATH is given
-	if logsPath := envWithDefault("", "LOGS_PATH"); logsPath != "" {
+	logsPath = envWithDefault(logsPath, "LOGS_PATH")
+	if logsPath != "" {
 		paths.SetLogs(logsPath)
 		// ensure that the logs directory exists
 		if err := os.MkdirAll(filepath.Join(logsPath), 0755); err != nil {
 			return fmt.Errorf("preparing LOGS_PATH(%s) failed: %s", logsPath, err)
 		}
 	}
+	// persist the paths so other commands in the container will use the correct paths
+	if writePaths {
+		if err := writeContainerPaths(originalTop, statePath, configPath, logsPath); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+type containerPaths struct {
+	StatePath  string `config:"state_path" yaml:"state_path"`
+	ConfigPath string `config:"state_path" yaml:"config_path,omitempty"`
+	LogsPath   string `config:"state_path" yaml:"logs_path,omitempty"`
+}
+
+func writeContainerPaths(original, statePath, configPath, logsPath string) error {
+	pathFile := filepath.Join(original, "container-paths.yml")
+	fp, err := os.Create(pathFile)
+	if err != nil {
+		return fmt.Errorf("failed creating %s: %s", pathFile, err)
+	}
+	b, err := yaml.Marshal(containerPaths{
+		StatePath:  statePath,
+		ConfigPath: configPath,
+		LogsPath:   logsPath,
+	})
+	if err != nil {
+		return fmt.Errorf("failed to marshal for %s: %s", pathFile, err)
+	}
+	_, err = fp.Write(b)
+	if err != nil {
+		return fmt.Errorf("failed to write %s: %s", pathFile, err)
+	}
 	return nil
 }
 
+func tryContainerLoadPaths() error {
+	pathFile := filepath.Join(paths.Top(), "container-paths.yml")
+	_, err := os.Stat(pathFile)
+	if os.IsNotExist(err) {
+		// no container-paths.yml file exists, so nothing to do
+		return nil
+	}
+	cfg, err := config.LoadFile(pathFile)
+	if err != nil {
+		return fmt.Errorf("failed to load %s: %s", pathFile, err)
+	}
+	var paths containerPaths
+	err = cfg.Unpack(&paths)
+	if err != nil {
+		return fmt.Errorf("failed to unpack %s: %s", pathFile, err)
+	}
+	return setPaths(paths.StatePath, paths.ConfigPath, paths.LogsPath, false)
+}
+
 func syncDir(src string, dest string) error {
 	return filepath.Walk(src, func(path string, info os.FileInfo, err error) error {
 		if err != nil {

x-pack/elastic-agent/pkg/agent/cmd/inspect.go

@@ -84,6 +84,11 @@ func newInspectOutputCommandWithArgs(_ []string, streams *cli.IOStreams) *cobra.
 }
 
 func inspectConfig(cfgPath string) error {
+	err := tryContainerLoadPaths()
+	if err != nil {
+		return err
+	}
+
 	fullCfg, err := operations.LoadFullAgentConfig(cfgPath, true)
 	if err != nil {
 		return err

x-pack/elastic-agent/pkg/agent/cmd/status.go

@@ -48,6 +48,11 @@ func newStatusCommand(_ []string, streams *cli.IOStreams) *cobra.Command {
 }
 
 func statusCmd(streams *cli.IOStreams, cmd *cobra.Command, args []string) error {
+	err := tryContainerLoadPaths()
+	if err != nil {
+		return err
+	}
+
 	output, _ := cmd.Flags().GetString("output")
 	outputFunc, ok := outputs[output]
 	if !ok {