feature: Implement connections API.

backend/api/controllers/v1/forward/connections.go

@@ -8,6 +8,7 @@ import (
 	"git.terah.dev/imterah/hermes/api/dbcore"
 	"git.terah.dev/imterah/hermes/api/jwtcore"
 	"git.terah.dev/imterah/hermes/api/permissions"
+	"git.terah.dev/imterah/hermes/commonbackend"
 	"github.com/charmbracelet/log"
 	"github.com/gin-gonic/gin"
 	"github.com/go-playground/validator/v10"
@@ -18,17 +19,22 @@ type ConnectionsRequest struct {
 	Id    uint   `validate:"required" json:"id"`
 }
 
-type SanitizedBackends struct {
-	UserID            uint   `json:"user_id"`
-	Name              string `json:"name"`
-	Description       string `json:"description"`
-	Backend           string `json:"backend"`
-	BackendParameters string `json:"backend_parameters"`
+type ConnectionDetailsForConnection struct {
+	SourceIP   string `json:"sourceIP"`
+	SourcePort uint16 `json:"sourcePort"`
+	DestPort   uint16 `json:"destPort"`
+}
+
+type SanitizedConnection struct {
+	ClientIP string `json:"ip"`
+	Port     uint16 `json:"port"`
+
+	ConnectionDetails *ConnectionDetailsForConnection `json:"connectionDetails"`
 }
 
 type ConnectionsResponse struct {
-	Success bool                 `json:"success"`
-	Data    []*SanitizedBackends `json:"data"`
+	Success bool                   `json:"success"`
+	Data    []*SanitizedConnection `json:"data"`
 }
 
 func Connections(c *gin.Context) {
@@ -62,7 +68,7 @@ func Connections(c *gin.Context) {
 			log.Warnf("Failed to get user from the provided JWT token: %s", err.Error())
 
 			c.JSON(http.StatusInternalServerError, gin.H{
-				"error": "failed to parse token",
+				"error": "Failed to parse token",
 			})
 
 			return
@@ -77,11 +83,11 @@ func Connections(c *gin.Context) {
 		return
 	}
 
-	var routes []dbcore.Proxy
-	routesRequest := dbcore.DB.Where("id = ?", req.Id).First(&routes)
+	var proxy dbcore.Proxy
+	proxyRequest := dbcore.DB.Where("id = ?", req.Id).First(&proxy)
 
-	if routesRequest.Error != nil {
-		log.Warnf("failed to find proxy: %s", routesRequest.Error)
+	if proxyRequest.Error != nil {
+		log.Warnf("failed to find proxy: %s", proxyRequest.Error)
 
 		c.JSON(http.StatusInternalServerError, gin.H{
 			"error": "Failed to find forward entry",
@@ -90,9 +96,9 @@ func Connections(c *gin.Context) {
 		return
 	}
 
-	routesExist := routesRequest.RowsAffected > 0
+	proxyExists := proxyRequest.RowsAffected > 0
 
-	if !routesExist {
+	if !proxyExists {
 		c.JSON(http.StatusBadRequest, gin.H{
 			"error": "No forward entry found",
 		})
@@ -100,13 +106,81 @@ func Connections(c *gin.Context) {
 		return
 	}
 
-	// FIXME(greysoh): not finished
-	var backends []dbcore.Backend
+	var backend dbcore.Backend
+	backendRequest := dbcore.DB.Where("id = ?", proxy.BackendID).First(&backend)
 
-	sanitizedBackends := make([]*SanitizedBackends, len(backends))
+	if backendRequest.Error != nil {
+		log.Warnf("failed to find backend: %s", backendRequest.Error)
 
-	c.JSON(http.StatusOK, gin.H{
-		"success": true,
-		"data":    sanitizedBackends,
-	})
+		c.JSON(http.StatusInternalServerError, gin.H{
+			"error": "Failed to find backend entry",
+		})
+
+		return
+	}
+
+	backendExists := backendRequest.RowsAffected > 0
+
+	if !backendExists {
+		c.JSON(http.StatusBadRequest, gin.H{
+			"error": "No forward entry found",
+		})
+
+		return
+	}
+
+	backendRuntime, ok := backendruntime.RunningBackends[backend.ID]
+
+	if !ok {
+		log.Warnf("Couldn't fetch backend runtime from backend ID #%d", backend.ID)
+
+		c.JSON(http.StatusInternalServerError, gin.H{
+			"error": "Couldn't fetch backend runtime",
+		})
+
+		return
+	}
+
+	backendRuntime.RuntimeCommands <- &commonbackend.ProxyConnectionsRequest{
+		Type: "proxyConnectionsRequest",
+	}
+
+	backendResponse := <-backendRuntime.RuntimeCommands
+
+	switch responseMessage := backendResponse.(type) {
+	case error:
+		log.Warnf("Failed to get response for backend: %s", responseMessage.Error())
+
+		c.JSON(http.StatusInternalServerError, gin.H{
+			"error": "Failed to get status response from backend",
+		})
+	case *commonbackend.ProxyConnectionsResponse:
+		sanitizedConnections := []*SanitizedConnection{}
+
+		for _, connection := range responseMessage.Connections {
+			if connection.SourceIP == proxy.SourceIP && connection.SourcePort == proxy.SourcePort && proxy.DestinationPort == proxy.DestinationPort {
+				sanitizedConnections = append(sanitizedConnections, &SanitizedConnection{
+					ClientIP: connection.ClientIP,
+					Port:     connection.ClientPort,
+
+					ConnectionDetails: &ConnectionDetailsForConnection{
+						SourceIP:   proxy.SourceIP,
+						SourcePort: proxy.SourcePort,
+						DestPort:   proxy.DestinationPort,
+					},
+				})
+			}
+		}
+
+		c.JSON(http.StatusOK, &ConnectionsResponse{
+			Success: true,
+			Data:    sanitizedConnections,
+		})
+	default:
+		log.Warnf("Got illegal response type for backend: %T", responseMessage)
+
+		c.JSON(http.StatusInternalServerError, gin.H{
+			"error": "Got illegal response type",
+		})
+	}
 }