f-28: generate metadata_port automatically at vm creation

Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

api/agent.yaml

@@ -402,14 +402,11 @@ components:
 
     VMCreateRequest:
       type: object
-      required: [name, metadata_port, interfaces, storage]
+      required: [name, interfaces, storage]
       properties:
         name:
           type: string
           example: vm-00001
-        metadata_port:
-          type: string
-          example: "80"
         memory:
           type: integer
           description: Memory in MB (default 512)

internal/api/agent/models.go

@@ -46,14 +46,13 @@ type VMStorage struct {
 }
 
 type VMCreateRequest struct {
-	Name         string        `json:"name"`
-	MetadataPort string        `json:"metadata_port"`
-	Memory       int           `json:"memory"`
-	CPUs         int           `json:"cpus"`
-	Password     string        `json:"password"`
-	SSHKey       string        `json:"sshkey"`
-	Interfaces   []VMInterface `json:"interfaces"`
-	Storage      []VMStorage   `json:"storage"`
+	Name       string        `json:"name"`
+	Memory     int           `json:"memory"`
+	CPUs       int           `json:"cpus"`
+	Password   string        `json:"password"`
+	SSHKey     string        `json:"sshkey"`
+	Interfaces []VMInterface `json:"interfaces"`
+	Storage    []VMStorage   `json:"storage"`
 }
 
 type VM struct {

internal/api/agent/vms.go

@@ -58,9 +58,9 @@ func (s *Server) startVM(w http.ResponseWriter, r *http.Request) {
 		json.NewEncoder(w).Encode(ErrorResponse{Error: "invalid request body"})
 		return
 	}
-	if req.Name == "" || req.MetadataPort == "" || len(req.Interfaces) == 0 || len(req.Storage) == 0 {
+	if req.Name == "" || len(req.Interfaces) == 0 || len(req.Storage) == 0 {
 		w.WriteHeader(http.StatusBadRequest)
-		json.NewEncoder(w).Encode(ErrorResponse{Error: "name, metadata_port, interfaces and storage are required"})
+		json.NewEncoder(w).Encode(ErrorResponse{Error: "name, interfaces and storage are required"})
 		return
 	}
 
@@ -78,15 +78,14 @@ func (s *Server) startVM(w http.ResponseWriter, r *http.Request) {
 	}
 
 	cmd := dispatcher.StartVMCommand{
-		Name:         req.Name,
-		Subnet:       primary.Subnet,
-		IP:           primary.IP,
-		MetadataPort: req.MetadataPort,
-		VolumePath:   req.Storage[0].Path,
-		Memory:       req.Memory,
-		CPUs:         req.CPUs,
-		Password:     req.Password,
-		SSHKey:       req.SSHKey,
+		Name:       req.Name,
+		Subnet:     primary.Subnet,
+		IP:         primary.IP,
+		VolumePath: req.Storage[0].Path,
+		Memory:     req.Memory,
+		CPUs:       req.CPUs,
+		Password:   req.Password,
+		SSHKey:     req.SSHKey,
 	}
 
 	if err := s.dispatcher.Prepare(cmd); err != nil {

internal/dispatcher/agent/vm_commands.go

@@ -2,7 +2,9 @@ package dispatcher
 
 import (
 	"fmt"
+	"math/rand"
 	"strconv"
+	"strings"
 	"time"
 
 	configuration "git.g3e.fr/syonad/two/internal/config/agent"
@@ -12,15 +14,14 @@ import (
 )
 
 type StartVMCommand struct {
-	Name         string
-	Subnet       string
-	IP           string
-	MetadataPort string
-	VolumePath   string
-	Memory       int
-	CPUs         int
-	Password     string
-	SSHKey       string
+	Name       string
+	Subnet     string
+	IP         string
+	VolumePath string
+	Memory     int
+	CPUs       int
+	Password   string
+	SSHKey     string
 }
 
 func (c StartVMCommand) Prepare(db *badger.DB, _ *configuration.Config) error {
@@ -34,10 +35,14 @@ func (c StartVMCommand) Prepare(db *badger.DB, _ *configuration.Config) error {
 	if subnetState == "deleting" || subnetState == "deleted" {
 		return fmt.Errorf("subnet %q is %s", c.Subnet, subnetState)
 	}
+	port, err := allocateMetadataPort(db)
+	if err != nil {
+		return fmt.Errorf("allocate metadata port: %w", err)
+	}
 	kv.AddInDB(db, "vm/"+c.Name+"/state", "starting")
 	kv.AddInDB(db, "vm/"+c.Name+"/subnet", c.Subnet)
 	kv.AddInDB(db, "vm/"+c.Name+"/ip", c.IP)
-	kv.AddInDB(db, "vm/"+c.Name+"/metadata_port", c.MetadataPort)
+	kv.AddInDB(db, "vm/"+c.Name+"/metadata_port", strconv.Itoa(port))
 	kv.AddInDB(db, "vm/"+c.Name+"/volume_path", c.VolumePath)
 	kv.AddInDB(db, "vm/"+c.Name+"/memory", strconv.Itoa(c.Memory))
 	kv.AddInDB(db, "vm/"+c.Name+"/cpus", strconv.Itoa(c.CPUs))
@@ -50,6 +55,28 @@ func (c StartVMCommand) Prepare(db *badger.DB, _ *configuration.Config) error {
 	return nil
 }
 
+func allocateMetadataPort(db *badger.DB) (int, error) {
+	entries, err := kv.ListByPrefix(db, "vm/")
+	if err != nil {
+		return 0, err
+	}
+	used := make(map[int]struct{})
+	for key, value := range entries {
+		if strings.HasSuffix(key, "/metadata_port") {
+			if p, err := strconv.Atoi(value); err == nil {
+				used[p] = struct{}{}
+			}
+		}
+	}
+	for range 100 {
+		p := rand.Intn(9000) + 1000
+		if _, taken := used[p]; !taken {
+			return p, nil
+		}
+	}
+	return 0, fmt.Errorf("no free metadata port available in [1000, 9999]")
+}
+
 func (c StartVMCommand) Execute(db *badger.DB, cfg *configuration.Config) error {
 	timeout := time.After(time.Duration(cfg.Dispatcher.TimeoutSeconds) * time.Second)
 	for {