feat: add server URL to served OpenAPI specs.

Author: outofcoffee

external/plugins/swaggerui/spec.go

@@ -1,7 +1,12 @@
 package main
 
 import (
+	"encoding/json"
+	"fmt"
 	"github.com/imposter-project/imposter-go/external/shared"
+	"gopkg.in/yaml.v3"
+	"os"
+	"path/filepath"
 	"strings"
 )
 
@@ -30,20 +35,112 @@ func generateSpecConfig(configs []shared.LightweightConfig) error {
 	return nil
 }
 
-// serveRawSpec serves the raw OpenAPI spec file based on the provided path.
+// getServerURL constructs the server URL from environment variables
+func getServerURL() string {
+	serverURL := os.Getenv("IMPOSTER_SERVER_URL")
+	if serverURL != "" {
+		return serverURL
+	}
+
+	port := os.Getenv("IMPOSTER_PORT")
+	if port == "" {
+		port = "8080"
+	}
+
+	var hostSuffix string
+	if port != "80" {
+		hostSuffix = fmt.Sprintf(":%s", port)
+	}
+	return fmt.Sprintf("http://localhost%s", hostSuffix)
+}
+
+// serveRawSpec serves the OpenAPI spec file with server URL modifications.
 // If no matching spec is found, it returns nil.
 func serveRawSpec(path string) *shared.HandlerResponse {
-	var response *shared.HandlerResponse
 	for _, specConfig := range specConfigs {
 		if path == specConfig.URL {
-			// TODO instead of serving the raw spec, parse it and add the server URL as the first server entry, then marshal it back to JSON.
-			response = &shared.HandlerResponse{
-				FileBaseDir: specConfig.ConfigDir,
-				StatusCode:  200,
-				File:        specConfig.OriginalPath,
+			// Read and parse the spec file
+			specPath := filepath.Join(specConfig.ConfigDir, specConfig.OriginalPath)
+			specData, err := os.ReadFile(specPath)
+			if err != nil {
+				return &shared.HandlerResponse{
+					StatusCode: 500,
+					Body:       []byte(fmt.Sprintf("Error reading spec file: %v", err)),
+				}
+			}
+
+			// Parse the spec into a map
+			var specMap map[string]interface{}
+
+			// YAML parser will handle both YAML and JSON formats
+			if err := yaml.Unmarshal(specData, &specMap); err != nil {
+				return &shared.HandlerResponse{
+					StatusCode: 500,
+					Body:       []byte(fmt.Sprintf("Error parsing spec file: %v", err)),
+				}
+			}
+
+			// Add server URL to the spec
+			serverURL := getServerURL()
+
+			// Check if this is OpenAPI 3.x or Swagger 2.0
+			if openapi, exists := specMap["openapi"]; exists {
+				// OpenAPI 3.x - add to servers array
+				if openapiVersion, ok := openapi.(string); ok && strings.HasPrefix(openapiVersion, "3.") {
+					servers, exists := specMap["servers"]
+					if !exists {
+						servers = []interface{}{}
+					}
+
+					serverList, ok := servers.([]interface{})
+					if !ok {
+						serverList = []interface{}{}
+					}
+
+					// Add server URL as first entry
+					newServer := map[string]interface{}{"url": serverURL}
+					serverList = append([]interface{}{newServer}, serverList...)
+					specMap["servers"] = serverList
+				}
+			} else if _, exists := specMap["swagger"]; exists {
+				// Swagger 2.0 - set basePath and host
+				if swaggerVersion, ok := specMap["swagger"].(string); ok && strings.HasPrefix(swaggerVersion, "2.") {
+					// Parse the server URL to extract host and basePath
+					if strings.HasPrefix(serverURL, "http://") {
+						serverURL = strings.TrimPrefix(serverURL, "http://")
+					} else if strings.HasPrefix(serverURL, "https://") {
+						serverURL = strings.TrimPrefix(serverURL, "https://")
+						specMap["schemes"] = []interface{}{"https"}
+					}
+
+					parts := strings.SplitN(serverURL, "/", 2)
+					specMap["host"] = parts[0]
+
+					if len(parts) > 1 {
+						specMap["basePath"] = "/" + parts[1]
+					} else {
+						specMap["basePath"] = "/"
+					}
+				}
+			}
+
+			// Marshal back to JSON
+			jsonData, err := json.MarshalIndent(specMap, "", "  ")
+			if err != nil {
+				return &shared.HandlerResponse{
+					StatusCode: 500,
+					Body:       []byte(fmt.Sprintf("Error marshalling spec: %v", err)),
+				}
+			}
+
+			return &shared.HandlerResponse{
+				StatusCode: 200,
+				Body:       jsonData,
+				Headers: map[string]string{
+					"Content-Type": "application/json",
+				},
 			}
-			break
 		}
 	}
-	return response
+	return nil
 }