Add OpenTelemetry Configuration Management (#861)

Author: mauriciocoder

cmd/thv/app/config.go

@@ -141,6 +141,8 @@ func init() {
 	configCmd.AddCommand(getRegistryURLCmd)
 	configCmd.AddCommand(unsetRegistryURLCmd)
 
+	// Add OTEL parent command to config
+	configCmd.AddCommand(OtelCmd)
 }
 
 func registerClientCmdFunc(cmd *cobra.Command, args []string) error {

cmd/thv/app/otel.go

@@ -0,0 +1,269 @@
+package app
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	"github.com/stacklok/toolhive/pkg/config"
+)
+
+// OtelCmd is the parent command for OpenTelemetry configuration
+var OtelCmd = &cobra.Command{
+	Use:   "otel",
+	Short: "Manage OpenTelemetry configuration",
+	Long:  "Configure OpenTelemetry settings for observability and monitoring of MCP servers.",
+}
+
+var setOtelEndpointCmd = &cobra.Command{
+	Use:   "set-endpoint <endpoint>",
+	Short: "Set the OpenTelemetry endpoint URL",
+	Long: `Set the OpenTelemetry OTLP endpoint URL for tracing and metrics.
+This endpoint will be used by default when running MCP servers unless overridden by the --otel-endpoint flag.
+
+Example:
+  thv config otel set-endpoint https://api.honeycomb.io`,
+	Args: cobra.ExactArgs(1),
+	RunE: setOtelEndpointCmdFunc,
+}
+
+var getOtelEndpointCmd = &cobra.Command{
+	Use:   "get-endpoint",
+	Short: "Get the currently configured OpenTelemetry endpoint",
+	Long:  "Display the OpenTelemetry endpoint URL that is currently configured.",
+	RunE:  getOtelEndpointCmdFunc,
+}
+
+var unsetOtelEndpointCmd = &cobra.Command{
+	Use:   "unset-endpoint",
+	Short: "Remove the configured OpenTelemetry endpoint",
+	Long:  "Remove the OpenTelemetry endpoint configuration.",
+	RunE:  unsetOtelEndpointCmdFunc,
+}
+
+var setOtelSamplingRateCmd = &cobra.Command{
+	Use:   "set-sampling-rate <rate>",
+	Short: "Set the OpenTelemetry sampling rate",
+	Long: `Set the OpenTelemetry trace sampling rate (between 0.0 and 1.0).
+This sampling rate will be used by default when running MCP servers unless overridden by the --otel-sampling-rate flag.
+
+Example:
+  thv config otel set-sampling-rate 0.1`,
+	Args: cobra.ExactArgs(1),
+	RunE: setOtelSamplingRateCmdFunc,
+}
+
+var getOtelSamplingRateCmd = &cobra.Command{
+	Use:   "get-sampling-rate",
+	Short: "Get the currently configured OpenTelemetry sampling rate",
+	Long:  "Display the OpenTelemetry sampling rate that is currently configured.",
+	RunE:  getOtelSamplingRateCmdFunc,
+}
+
+var unsetOtelSamplingRateCmd = &cobra.Command{
+	Use:   "unset-sampling-rate",
+	Short: "Remove the configured OpenTelemetry sampling rate",
+	Long:  "Remove the OpenTelemetry sampling rate configuration.",
+	RunE:  unsetOtelSamplingRateCmdFunc,
+}
+
+var setOtelEnvVarsCmd = &cobra.Command{
+	Use:   "set-env-vars <var1,var2,...>",
+	Short: "Set the OpenTelemetry environment variables",
+	Long: `Set the list of environment variable names to include in OpenTelemetry spans.
+These environment variables will be used by default when running MCP servers unless overridden by the --otel-env-vars flag.
+
+Example:
+  thv config otel set-env-vars USER,HOME,PATH`,
+	Args: cobra.ExactArgs(1),
+	RunE: setOtelEnvVarsCmdFunc,
+}
+
+var getOtelEnvVarsCmd = &cobra.Command{
+	Use:   "get-env-vars",
+	Short: "Get the currently configured OpenTelemetry environment variables",
+	Long:  "Display the OpenTelemetry environment variables that are currently configured.",
+	RunE:  getOtelEnvVarsCmdFunc,
+}
+
+var unsetOtelEnvVarsCmd = &cobra.Command{
+	Use:   "unset-env-vars",
+	Short: "Remove the configured OpenTelemetry environment variables",
+	Long:  "Remove the OpenTelemetry environment variables configuration.",
+	RunE:  unsetOtelEnvVarsCmdFunc,
+}
+
+// init sets up the OTEL command hierarchy
+func init() {
+	// Add OTEL subcommands to otel command
+	OtelCmd.AddCommand(setOtelEndpointCmd)
+	OtelCmd.AddCommand(getOtelEndpointCmd)
+	OtelCmd.AddCommand(unsetOtelEndpointCmd)
+	OtelCmd.AddCommand(setOtelSamplingRateCmd)
+	OtelCmd.AddCommand(getOtelSamplingRateCmd)
+	OtelCmd.AddCommand(unsetOtelSamplingRateCmd)
+	OtelCmd.AddCommand(setOtelEnvVarsCmd)
+	OtelCmd.AddCommand(getOtelEnvVarsCmd)
+	OtelCmd.AddCommand(unsetOtelEnvVarsCmd)
+}
+
+func setOtelEndpointCmdFunc(_ *cobra.Command, args []string) error {
+	endpoint := args[0]
+
+	// The endpoint should not start with http:// or https://
+	if endpoint != "" && (strings.HasPrefix(endpoint, "http://") || strings.HasPrefix(endpoint, "https://")) {
+		return fmt.Errorf("endpoint URL should not start with http:// or https://")
+	}
+
+	// Update the configuration
+	err := config.UpdateConfig(func(c *config.Config) {
+		c.OTEL.Endpoint = endpoint
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update configuration: %w", err)
+	}
+
+	fmt.Printf("Successfully set OpenTelemetry endpoint: %s\n", endpoint)
+	return nil
+}
+
+func getOtelEndpointCmdFunc(_ *cobra.Command, _ []string) error {
+	cfg := config.GetConfig()
+
+	if cfg.OTEL.Endpoint == "" {
+		fmt.Println("No OpenTelemetry endpoint is currently configured.")
+		return nil
+	}
+
+	fmt.Printf("Current OpenTelemetry endpoint: %s\n", cfg.OTEL.Endpoint)
+	return nil
+}
+
+func unsetOtelEndpointCmdFunc(_ *cobra.Command, _ []string) error {
+	cfg := config.GetConfig()
+
+	if cfg.OTEL.Endpoint == "" {
+		fmt.Println("No OpenTelemetry endpoint is currently configured.")
+		return nil
+	}
+
+	// Update the configuration
+	err := config.UpdateConfig(func(c *config.Config) {
+		c.OTEL.Endpoint = ""
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update configuration: %w", err)
+	}
+
+	fmt.Println("Successfully removed OpenTelemetry endpoint configuration.")
+	return nil
+}
+
+func setOtelSamplingRateCmdFunc(_ *cobra.Command, args []string) error {
+	rate, err := strconv.ParseFloat(args[0], 64)
+	if err != nil {
+		return fmt.Errorf("invalid sampling rate format: %w", err)
+	}
+
+	// Validate the rate
+	if rate < 0.0 || rate > 1.0 {
+		return fmt.Errorf("sampling rate must be between 0.0 and 1.0")
+	}
+
+	// Update the configuration
+	err = config.UpdateConfig(func(c *config.Config) {
+		c.OTEL.SamplingRate = rate
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update configuration: %w", err)
+	}
+
+	fmt.Printf("Successfully set OpenTelemetry sampling rate: %f\n", rate)
+	return nil
+}
+
+func getOtelSamplingRateCmdFunc(_ *cobra.Command, _ []string) error {
+	cfg := config.GetConfig()
+
+	if cfg.OTEL.SamplingRate == 0.0 {
+		fmt.Println("No OpenTelemetry sampling rate is currently configured.")
+		return nil
+	}
+
+	fmt.Printf("Current OpenTelemetry sampling rate: %f\n", cfg.OTEL.SamplingRate)
+	return nil
+}
+
+func unsetOtelSamplingRateCmdFunc(_ *cobra.Command, _ []string) error {
+	cfg := config.GetConfig()
+
+	if cfg.OTEL.SamplingRate == 0.0 {
+		fmt.Println("No OpenTelemetry sampling rate is currently configured.")
+		return nil
+	}
+
+	// Update the configuration
+	err := config.UpdateConfig(func(c *config.Config) {
+		c.OTEL.SamplingRate = 0.0
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update configuration: %w", err)
+	}
+
+	fmt.Println("Successfully removed OpenTelemetry sampling rate configuration.")
+	return nil
+}
+
+func setOtelEnvVarsCmdFunc(_ *cobra.Command, args []string) error {
+	vars := strings.Split(args[0], ",")
+
+	// Trim whitespace from each variable name
+	for i, varName := range vars {
+		vars[i] = strings.TrimSpace(varName)
+	}
+
+	// Update the configuration
+	err := config.UpdateConfig(func(c *config.Config) {
+		c.OTEL.EnvVars = vars
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update configuration: %w", err)
+	}
+
+	fmt.Printf("Successfully set OpenTelemetry environment variables: %v\n", vars)
+	return nil
+}
+
+func getOtelEnvVarsCmdFunc(_ *cobra.Command, _ []string) error {
+	cfg := config.GetConfig()
+
+	if len(cfg.OTEL.EnvVars) == 0 {
+		fmt.Println("No OpenTelemetry environment variables are currently configured.")
+		return nil
+	}
+
+	fmt.Printf("Current OpenTelemetry environment variables: %v\n", cfg.OTEL.EnvVars)
+	return nil
+}
+
+func unsetOtelEnvVarsCmdFunc(_ *cobra.Command, _ []string) error {
+	cfg := config.GetConfig()
+
+	if len(cfg.OTEL.EnvVars) == 0 {
+		fmt.Println("No OpenTelemetry environment variables are currently configured.")
+		return nil
+	}
+
+	// Update the configuration
+	err := config.UpdateConfig(func(c *config.Config) {
+		c.OTEL.EnvVars = []string{}
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update configuration: %w", err)
+	}
+
+	fmt.Println("Successfully removed OpenTelemetry environment variables configuration.")
+	return nil
+}

cmd/thv/app/run.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"github.com/stacklok/toolhive/pkg/config"
 	"github.com/stacklok/toolhive/pkg/container"
 	"github.com/stacklok/toolhive/pkg/logger"
 	"github.com/stacklok/toolhive/pkg/permissions"
@@ -225,6 +226,25 @@ func runCmdFunc(cmd *cobra.Command, args []string) error {
 	oidcJwksURL := GetStringFlagOrEmpty(cmd, "oidc-jwks-url")
 	oidcClientID := GetStringFlagOrEmpty(cmd, "oidc-client-id")
 
+	// Get OTEL flag values with config fallbacks
+	cfg := config.GetConfig()
+
+	// Use config values as fallbacks for OTEL flags if not explicitly set
+	finalOtelEndpoint := runOtelEndpoint
+	if !cmd.Flags().Changed("otel-endpoint") && cfg.OTEL.Endpoint != "" {
+		finalOtelEndpoint = cfg.OTEL.Endpoint
+	}
+
+	finalOtelSamplingRate := runOtelSamplingRate
+	if !cmd.Flags().Changed("otel-sampling-rate") && cfg.OTEL.SamplingRate != 0.0 {
+		finalOtelSamplingRate = cfg.OTEL.SamplingRate
+	}
+
+	finalOtelEnvironmentVariables := runOtelEnvironmentVariables
+	if !cmd.Flags().Changed("otel-env-vars") && len(cfg.OTEL.EnvVars) > 0 {
+		finalOtelEnvironmentVariables = cfg.OTEL.EnvVars
+	}
+
 	// Create container runtime
 	rt, err := container.NewFactory().Create(ctx)
 	if err != nil {
@@ -285,13 +305,13 @@ func runCmdFunc(cmd *cobra.Command, args []string) error {
 		oidcAudience,
 		oidcJwksURL,
 		oidcClientID,
-		runOtelEndpoint,
+		finalOtelEndpoint,
 		runOtelServiceName,
-		runOtelSamplingRate,
+		finalOtelSamplingRate,
 		runOtelHeaders,
 		runOtelInsecure,
 		runOtelEnablePrometheusMetricsPath,
-		runOtelEnvironmentVariables,
+		finalOtelEnvironmentVariables,
 		runIsolateNetwork,
 		runK8sPodPatch,
 		envVarValidator,