Set all required environment variables and arguments when updating tools for an MCP server

this also prints the logs in case there's an error.

Signed-off-by: Juan Antonio Osorio <[email protected]>

Author: JAORMX

cmd/update-tools/main.go

@@ -199,6 +199,7 @@ func fetchToolsFromMCP(serverName string) ([]string, error) {
 	}
 
 	// Run the MCP server
+	logger.Infof("Starting temporary MCP server: %s", serverName)
 	tempName, err := client.RunServer(spec, serverName)
 	if err != nil {
 		return nil, fmt.Errorf("failed to run server: %w", err)
@@ -208,14 +209,22 @@ func fetchToolsFromMCP(serverName string) ([]string, error) {
 		if err := client.StopServer(tempName); err != nil {
 			logger.Warnf("Failed to stop temporary server %s: %v", tempName, err)
 		}
-		if err := client.RemoveServer(tempName); err != nil {
-			logger.Warnf("Failed to remove temporary server %s: %v", tempName, err)
-		}
+		//if err := client.RemoveServer(tempName); err != nil {
+		//	logger.Warnf("Failed to remove temporary server %s: %v", tempName, err)
+		//}
 	}()
 
 	// Query the server for tools
 	tools, err := client.ListTools(tempName)
 	if err != nil {
+		// Get Logs for debugging
+		logs, logErr := client.Logs(tempName)
+		if logErr != nil {
+			logger.Warnf("Failed to fetch logs from temporary server %s: %v", tempName, logErr)
+		}
+		if logs != "" {
+			logger.Infof("Logs from temporary server %s:\n%s", tempName, logs)
+		}
 		return nil, fmt.Errorf("failed to list tools: %w", err)
 	}
 

pkg/toolhive/builder.go

@@ -65,13 +65,19 @@ func BuildRunCommand(spec *types.RegistryEntry, tempName, image string) []string
 		// Add environment variables
 		if spec.ImageMetadata.EnvVars != nil {
 			for _, envVar := range spec.ImageMetadata.EnvVars {
-				if envVar.Secret {
-					// For secrets, use placeholder values if required
-					if envVar.Required {
-						builder.AddEnvVar(envVar.Name, "placeholder")
-					}
-				} else if envVar.Default != "" {
+				// Precedence: explicit default from spec > required flag > secret flag
+				if envVar.Default != "" {
 					builder.AddEnvVar(envVar.Name, envVar.Default)
+					continue
+				}
+				if envVar.Required {
+					// Inject a dummy value to allow server startup and tool discovery
+					builder.AddEnvVar(envVar.Name, "placeholder")
+					continue
+				}
+				if envVar.Secret {
+					// Even when not required, inject a dummy for secrets to surface optional tools
+					builder.AddEnvVar(envVar.Name, "placeholder")
 				}
 			}
 		}
@@ -85,5 +91,16 @@ func BuildRunCommand(spec *types.RegistryEntry, tempName, image string) []string
 	// Add the image as the last positional argument
 	builder.AddPositional(image)
 
+	// Append registry-specified args after the image using the standard "--" separator
+	// per ToolHive docs (arguments after "--" are passed to the server process).
+	if spec.ImageMetadata != nil && len(spec.Args) > 0 {
+		builder.AddPositional("--")
+		for _, a := range spec.Args {
+			if a != "" {
+				builder.AddPositional(a)
+			}
+		}
+	}
+
 	return builder.Build()
 }

pkg/toolhive/client.go

@@ -94,6 +94,22 @@ func (c *Client) ListTools(serverName string) ([]string, error) {
 	return ParseToolsJSON(string(output))
 }
 
+// Logs retrieves logs from a running MCP server
+func (c *Client) Logs(serverName string) (string, error) {
+	logsArgs := NewCommandBuilder("logs").
+		AddFlag("--follow", "false").
+		AddPositional(serverName).
+		Build()
+
+	logsCmd := exec.Command(c.thvPath, logsArgs...) // #nosec G204 - thvPath is validated in NewClient
+	output, err := logsCmd.CombinedOutput()
+	if err != nil {
+		return "", fmt.Errorf("thv logs failed: %w\nOutput: %s", err, string(output))
+	}
+
+	return string(output), nil
+}
+
 // StopServer stops a running MCP server
 func (c *Client) StopServer(serverName string) error {
 	stopCmd := exec.Command(c.thvPath, "stop", serverName) // #nosec G204 - thvPath is validated in NewClient