Cherry-pick #26275 to 7.13: Enable agent to send custom headers to ki…

…bana/ES (#26362)

* update

* Update CHANGELOG.next.asciidoc

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

@@ -110,3 +110,4 @@
 - Add --fleet-server-service-token and FLEET_SERVER_SERVICE_TOKEN options {pull}25083[25083]
 - Keep http and logging config during enroll {pull}25132[25132]
 - Log output of container to $LOGS_PATH/elastic-agent-start.log when LOGS_PATH set {pull}25150[25150]
+- Enable agent to send custom headers to kibana/ES {pull}26275[26275]

x-pack/elastic-agent/pkg/agent/application/info/agent_id.go

@@ -29,6 +29,7 @@ const maxRetriesloadAgentInfo = 5
 
 type persistentAgentInfo struct {
 	ID             string                                 `json:"id" yaml:"id" config:"id"`
+	Headers        map[string]string                      `json:"headers" yaml:"headers" config:"headers"`
 	LogLevel       string                                 `json:"logging.level,omitempty" yaml:"logging.level,omitempty" config:"logging.level,omitempty"`
 	MonitoringHTTP *monitoringConfig.MonitoringHTTPConfig `json:"monitoring.http,omitempty" yaml:"monitoring.http,omitempty" config:"monitoring.http,omitempty"`
 }

x-pack/elastic-agent/pkg/agent/application/info/agent_info.go

@@ -13,6 +13,7 @@ import (
 type AgentInfo struct {
 	agentID  string
 	logLevel string
+	headers  map[string]string
 }
 
 // NewAgentInfoWithLog creates a new agent information.
@@ -30,6 +31,7 @@ func NewAgentInfoWithLog(level string, createAgentID bool) (*AgentInfo, error) {
 	return &AgentInfo{
 		agentID:  agentInfo.ID,
 		logLevel: agentInfo.LogLevel,
+		headers:  agentInfo.Headers,
 	}, nil
 }
 
@@ -84,3 +86,8 @@ func (*AgentInfo) Version() string {
 func (*AgentInfo) Snapshot() bool {
 	return release.Snapshot()
 }
+
+// Headers returns custom headers used to communicate with elasticsearch.
+func (i *AgentInfo) Headers() map[string]string {
+	return i.headers
+}

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

@@ -271,7 +271,7 @@ func runContainerCmd(streams *cli.IOStreams, cmd *cobra.Command, cfg setupConfig
 	}
 
 	if cfg.Kibana.Fleet.Setup {
-		client, err = kibanaClient(cfg.Kibana)
+		client, err = kibanaClient(cfg.Kibana, cfg.Kibana.Headers)
 		if err != nil {
 			return err
 		}
@@ -286,7 +286,7 @@ func runContainerCmd(streams *cli.IOStreams, cmd *cobra.Command, cfg setupConfig
 		token := cfg.Fleet.EnrollmentToken
 		if token == "" && !cfg.FleetServer.Enable {
 			if client == nil {
-				client, err = kibanaClient(cfg.Kibana)
+				client, err = kibanaClient(cfg.Kibana, cfg.Kibana.Headers)
 				if err != nil {
 					return err
 				}
@@ -363,6 +363,11 @@ func buildEnrollArgs(cfg setupConfig, token string, policyID string) ([]string,
 		if cfg.FleetServer.CertKey != "" {
 			args = append(args, "--fleet-server-cert-key", cfg.FleetServer.CertKey)
 		}
+
+		for k, v := range cfg.FleetServer.Headers {
+			args = append(args, "--header", k+"="+v)
+		}
+
 		if cfg.Fleet.URL != "" {
 			args = append(args, "--url", cfg.Fleet.URL)
 		}
@@ -444,19 +449,21 @@ func kibanaFetchToken(cfg setupConfig, client *kibana.Client, policy *kibanaPoli
 	return keyDetail.Item.APIKey, nil
 }
 
-func kibanaClient(cfg kibanaConfig) (*kibana.Client, error) {
+func kibanaClient(cfg kibanaConfig, headers map[string]string) (*kibana.Client, error) {
 	var tls *tlscommon.Config
 	if cfg.Fleet.CA != "" {
 		tls = &tlscommon.Config{
 			CAs: []string{cfg.Fleet.CA},
 		}
 	}
+
 	return kibana.NewClientWithConfig(&kibana.ClientConfig{
 		Host:          cfg.Fleet.Host,
 		Username:      cfg.Fleet.Username,
 		Password:      cfg.Fleet.Password,
 		IgnoreVersion: true,
 		TLS:           tls,
+		Headers:       headers,
 	})
 }
 
@@ -518,6 +525,27 @@ func envBool(keys ...string) bool {
 	return false
 }
 
+func envMap(key string) map[string]string {
+	m := make(map[string]string)
+	prefix := key + "="
+	for _, env := range os.Environ() {
+		if !strings.HasPrefix(env, prefix) {
+			continue
+		}
+
+		envVal := strings.TrimPrefix(env, prefix)
+
+		keyValue := strings.SplitN(envVal, "=", 2)
+		if len(keyValue) != 2 {
+			continue
+		}
+
+		m[keyValue[0]] = keyValue[1]
+	}
+
+	return m
+}
+
 func isTrue(val string) bool {
 	trueVals := []string{"1", "true", "yes", "y"}
 	val = strings.ToLower(val)
@@ -815,114 +843,6 @@ type kibanaAPIKeyDetail struct {
 	Item kibanaAPIKey `json:"item"`
 }
 
-// setup configuration
-
-type setupConfig struct {
-	Fleet       fleetConfig       `config:"fleet"`
-	FleetServer fleetServerConfig `config:"fleet_server"`
-	Kibana      kibanaConfig      `config:"kibana"`
-}
-
-type elasticsearchConfig struct {
-	CA           string `config:"ca"`
-	Host         string `config:"host"`
-	Username     string `config:"username"`
-	Password     string `config:"password"`
-	ServiceToken string `config:"service_token"`
-}
-
-type fleetConfig struct {
-	CA              string `config:"ca"`
-	Enroll          bool   `config:"enroll"`
-	EnrollmentToken string `config:"enrollment_token"`
-	Force           bool   `config:"force"`
-	Insecure        bool   `config:"insecure"`
-	TokenName       string `config:"token_name"`
-	TokenPolicyName string `config:"token_policy_name"`
-	URL             string `config:"url"`
-}
-
-type fleetServerConfig struct {
-	Cert          string              `config:"cert"`
-	CertKey       string              `config:"cert_key"`
-	Elasticsearch elasticsearchConfig `config:"elasticsearch"`
-	Enable        bool                `config:"enable"`
-	Host          string              `config:"host"`
-	InsecureHTTP  bool                `config:"insecure_http"`
-	PolicyID      string              `config:"policy_id"`
-	Port          string              `config:"port"`
-}
-
-type kibanaConfig struct {
-	Fleet              kibanaFleetConfig `config:"fleet"`
-	RetrySleepDuration time.Duration     `config:"retry_sleep_duration"`
-	RetryMaxCount      int               `config:"retry_max_count"`
-}
-
-type kibanaFleetConfig struct {
-	CA       string `config:"ca"`
-	Host     string `config:"host"`
-	Password string `config:"password"`
-	Setup    bool   `config:"setup"`
-	Username string `config:"username"`
-}
-
-func defaultAccessConfig() (setupConfig, error) {
-	retrySleepDuration, err := envDurationWithDefault(defaultRequestRetrySleep, requestRetrySleepEnv)
-	if err != nil {
-		return setupConfig{}, err
-	}
-
-	retryMaxCount, err := envIntWithDefault(defaultMaxRequestRetries, maxRequestRetriesEnv)
-	if err != nil {
-		return setupConfig{}, err
-	}
-
-	cfg := setupConfig{
-		Fleet: fleetConfig{
-			CA:              envWithDefault("", "FLEET_CA", "KIBANA_CA", "ELASTICSEARCH_CA"),
-			Enroll:          envBool("FLEET_ENROLL", "FLEET_SERVER_ENABLE"),
-			EnrollmentToken: envWithDefault("", "FLEET_ENROLLMENT_TOKEN"),
-			Force:           envBool("FLEET_FORCE"),
-			Insecure:        envBool("FLEET_INSECURE"),
-			TokenName:       envWithDefault("Default", "FLEET_TOKEN_NAME"),
-			TokenPolicyName: envWithDefault("", "FLEET_TOKEN_POLICY_NAME"),
-			URL:             envWithDefault("", "FLEET_URL"),
-		},
-		FleetServer: fleetServerConfig{
-			Cert:    envWithDefault("", "FLEET_SERVER_CERT"),
-			CertKey: envWithDefault("", "FLEET_SERVER_CERT_KEY"),
-			Elasticsearch: elasticsearchConfig{
-				Host:         envWithDefault("http://elasticsearch:9200", "FLEET_SERVER_ELASTICSEARCH_HOST", "ELASTICSEARCH_HOST"),
-				Username:     envWithDefault("elastic", "FLEET_SERVER_ELASTICSEARCH_USERNAME", "ELASTICSEARCH_USERNAME"),
-				Password:     envWithDefault("changeme", "FLEET_SERVER_ELASTICSEARCH_PASSWORD", "ELASTICSEARCH_PASSWORD"),
-				ServiceToken: envWithDefault("", "FLEET_SERVER_SERVICE_TOKEN"),
-				CA:           envWithDefault("", "FLEET_SERVER_ELASTICSEARCH_CA", "ELASTICSEARCH_CA"),
-			},
-			Enable:       envBool("FLEET_SERVER_ENABLE"),
-			Host:         envWithDefault("", "FLEET_SERVER_HOST"),
-			InsecureHTTP: envBool("FLEET_SERVER_INSECURE_HTTP"),
-			PolicyID:     envWithDefault("", "FLEET_SERVER_POLICY_ID", "FLEET_SERVER_POLICY"),
-			Port:         envWithDefault("", "FLEET_SERVER_PORT"),
-		},
-		Kibana: kibanaConfig{
-			Fleet: kibanaFleetConfig{
-				// Remove FLEET_SETUP in 8.x
-				// The FLEET_SETUP environment variable boolean is a fallback to the old name. The name was updated to
-				// reflect that its setting up Fleet in Kibana versus setting up Fleet Server.
-				Setup:    envBool("KIBANA_FLEET_SETUP", "FLEET_SETUP"),
-				Host:     envWithDefault("http://kibana:5601", "KIBANA_FLEET_HOST", "KIBANA_HOST"),
-				Username: envWithDefault("elastic", "KIBANA_FLEET_USERNAME", "KIBANA_USERNAME", "ELASTICSEARCH_USERNAME"),
-				Password: envWithDefault("changeme", "KIBANA_FLEET_PASSWORD", "KIBANA_PASSWORD", "ELASTICSEARCH_PASSWORD"),
-				CA:       envWithDefault("", "KIBANA_FLEET_CA", "KIBANA_CA", "ELASTICSEARCH_CA"),
-			},
-			RetrySleepDuration: retrySleepDuration,
-			RetryMaxCount:      retryMaxCount,
-		},
-	}
-	return cfg, nil
-}
-
 func envDurationWithDefault(defVal string, keys ...string) (time.Duration, error) {
 	valStr := defVal
 	for _, key := range keys {

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

@@ -10,6 +10,7 @@ import (
 	"os"
 	"os/signal"
 	"strconv"
+	"strings"
 	"syscall"
 
 	"github.com/elastic/beats/v7/x-pack/elastic-agent/pkg/agent/application/paths"
@@ -59,6 +60,7 @@ func addEnrollFlags(cmd *cobra.Command) {
 	cmd.Flags().Uint16P("fleet-server-port", "", 0, "Fleet Server HTTP binding port (overrides the policy)")
 	cmd.Flags().StringP("fleet-server-cert", "", "", "Certificate to use for exposed Fleet Server HTTPS endpoint")
 	cmd.Flags().StringP("fleet-server-cert-key", "", "", "Private key to use for exposed Fleet Server HTTPS endpoint")
+	cmd.Flags().StringSliceP("header", "", []string{}, "Headers used in communication with elasticsearch")
 	cmd.Flags().BoolP("fleet-server-insecure-http", "", false, "Expose Fleet Server over HTTP (not recommended; insecure)")
 	cmd.Flags().StringP("certificate-authorities", "a", "", "Comma separated list of root certificate for server verifications")
 	cmd.Flags().StringP("ca-sha256", "p", "", "Comma separated list of certificate authorities hash pins used for certificate verifications")
@@ -81,6 +83,7 @@ func buildEnrollmentFlags(cmd *cobra.Command, url string, token string) []string
 	fPort, _ := cmd.Flags().GetUint16("fleet-server-port")
 	fCert, _ := cmd.Flags().GetString("fleet-server-cert")
 	fCertKey, _ := cmd.Flags().GetString("fleet-server-cert-key")
+	fHeaders, _ := cmd.Flags().GetStringSlice("header")
 	fInsecure, _ := cmd.Flags().GetBool("fleet-server-insecure-http")
 	ca, _ := cmd.Flags().GetString("certificate-authorities")
 	sha256, _ := cmd.Flags().GetString("ca-sha256")
@@ -128,6 +131,12 @@ func buildEnrollmentFlags(cmd *cobra.Command, url string, token string) []string
 		args = append(args, "--fleet-server-cert-key")
 		args = append(args, fCertKey)
 	}
+
+	for k, v := range mapFromEnvList(fHeaders) {
+		args = append(args, "--header")
+		args = append(args, k+"="+v)
+	}
+
 	if fInsecure {
 		args = append(args, "--fleet-server-insecure-http")
 	}
@@ -211,6 +220,7 @@ func enroll(streams *cli.IOStreams, cmd *cobra.Command, args []string) error {
 	enrollmentToken, _ := cmd.Flags().GetString("enrollment-token")
 	fServer, _ := cmd.Flags().GetString("fleet-server-es")
 	fElasticSearchCA, _ := cmd.Flags().GetString("fleet-server-es-ca")
+	fHeaders, _ := cmd.Flags().GetStringSlice("header")
 	fServiceToken, _ := cmd.Flags().GetString("fleet-server-service-token")
 	fPolicy, _ := cmd.Flags().GetString("fleet-server-policy")
 	fHost, _ := cmd.Flags().GetString("fleet-server-host")
@@ -246,6 +256,7 @@ func enroll(streams *cli.IOStreams, cmd *cobra.Command, args []string) error {
 			CertKey:         fCertKey,
 			Insecure:        fInsecure,
 			SpawnAgent:      !fromInstall,
+			Headers:         mapFromEnvList(fHeaders),
 		},
 	}
 
@@ -285,3 +296,16 @@ func handleSignal(ctx context.Context) context.Context {
 
 	return ctx
 }
+
+func mapFromEnvList(envList []string) map[string]string {
+	m := make(map[string]string)
+	for _, kv := range envList {
+		keyValue := strings.SplitN(kv, "=", 2)
+		if len(keyValue) != 2 {
+			continue
+		}
+
+		m[keyValue[0]] = keyValue[1]
+	}
+	return m
+}

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

@@ -78,6 +78,7 @@ type enrollCmdFleetServerOption struct {
 	CertKey         string
 	Insecure        bool
 	SpawnAgent      bool
+	Headers         map[string]string
 }
 
 // enrollCmdOption define all the supported enrollment option.
@@ -232,7 +233,8 @@ func (c *enrollCmd) fleetServerBootstrap(ctx context.Context) (string, error) {
 		c.options.FleetServer.ConnStr, c.options.FleetServer.ServiceToken,
 		c.options.FleetServer.PolicyID,
 		c.options.FleetServer.Host, c.options.FleetServer.Port,
-		c.options.FleetServer.Cert, c.options.FleetServer.CertKey, c.options.FleetServer.ElasticsearchCA)
+		c.options.FleetServer.Cert, c.options.FleetServer.CertKey, c.options.FleetServer.ElasticsearchCA,
+		c.options.FleetServer.Headers)
 	if err != nil {
 		return "", err
 	}
@@ -412,7 +414,7 @@ func (c *enrollCmd) enroll(ctx context.Context, persistentConfig map[string]inte
 		return err
 	}
 
-	agentConfig, err := c.createAgentConfig(resp.Item.ID, persistentConfig)
+	agentConfig, err := c.createAgentConfig(resp.Item.ID, persistentConfig, c.options.FleetServer.Headers)
 	if err != nil {
 		return err
 	}
@@ -422,7 +424,8 @@ func (c *enrollCmd) enroll(ctx context.Context, persistentConfig map[string]inte
 			c.options.FleetServer.ConnStr, c.options.FleetServer.ServiceToken,
 			c.options.FleetServer.PolicyID,
 			c.options.FleetServer.Host, c.options.FleetServer.Port,
-			c.options.FleetServer.Cert, c.options.FleetServer.CertKey, c.options.FleetServer.ElasticsearchCA)
+			c.options.FleetServer.Cert, c.options.FleetServer.CertKey, c.options.FleetServer.ElasticsearchCA,
+			c.options.FleetServer.Headers)
 		if err != nil {
 			return err
 		}
@@ -717,7 +720,12 @@ func storeAgentInfo(s saver, reader io.Reader) error {
 	return nil
 }
 
-func createFleetServerBootstrapConfig(connStr string, serviceToken string, policyID string, host string, port uint16, cert string, key string, esCA string) (*configuration.FleetAgentConfig, error) {
+func createFleetServerBootstrapConfig(
+	connStr, serviceToken, policyID, host string,
+	port uint16,
+	cert, key, esCA string,
+	headers map[string]string,
+) (*configuration.FleetAgentConfig, error) {
 	es, err := configuration.ElasticsearchFromConnStr(connStr, serviceToken)
 	if err != nil {
 		return nil, err
@@ -733,6 +741,15 @@ func createFleetServerBootstrapConfig(connStr string, serviceToken string, polic
 	if port == 0 {
 		port = defaultFleetServerPort
 	}
+	if len(headers) > 0 {
+		if es.Headers == nil {
+			es.Headers = make(map[string]string)
+		}
+		// overwrites previously set headers
+		for k, v := range headers {
+			es.Headers[k] = v
+		}
+	}
 	cfg := configuration.DefaultFleetAgentConfig()
 	cfg.Enabled = true
 	cfg.Server = &configuration.FleetServerConfig{
@@ -773,11 +790,15 @@ func createFleetConfigFromEnroll(accessAPIKey string, cli remote.Config) (*confi
 	return cfg, nil
 }
 
-func (c *enrollCmd) createAgentConfig(agentID string, pc map[string]interface{}) (map[string]interface{}, error) {
+func (c *enrollCmd) createAgentConfig(agentID string, pc map[string]interface{}, headers map[string]string) (map[string]interface{}, error) {
 	agentConfig := map[string]interface{}{
 		"id": agentID,
 	}
 
+	if len(headers) > 0 {
+		agentConfig["headers"] = headers
+	}
+
 	if c.options.Staging != "" {
 		staging := fmt.Sprintf("https://staging.elastic.co/%s-%s/downloads/", release.Version(), c.options.Staging[:8])
 		agentConfig["download"] = map[string]interface{}{