feat: update agent button on server page

server/internal/services/dispatch.go

@@ -1,7 +1,11 @@
 package services
 
 import (
+	"encoding/json"
 	"fmt"
+	"net/http"
+	"os"
+	"strings"
 	"sync"
 
 	"github.com/google/uuid"
@@ -67,6 +71,69 @@ type KeyGenParams struct {
 	Comment    string
 }
 
+// GetLatestAgentVersion queries the Gitea API for the latest agent/v* release tag
+// and returns just the version number (e.g. "1.2.3").
+func GetLatestAgentVersion() (string, error) {
+	giteaHost := os.Getenv("GITEA_HOST")
+	if giteaHost == "" {
+		giteaHost = "gitea.example.com"
+	}
+	url := fmt.Sprintf("https://%s/api/v1/repos/mrhid6/keymanager/releases?limit=20", giteaHost)
+	resp, err := http.Get(url) //nolint:gosec
+	if err != nil {
+		return "", fmt.Errorf("fetch releases: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("Gitea API returned HTTP %d", resp.StatusCode)
+	}
+
+	var releases []struct {
+		TagName string `json:"tag_name"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&releases); err != nil {
+		return "", fmt.Errorf("decode releases: %w", err)
+	}
+
+	for _, r := range releases {
+		if strings.HasPrefix(r.TagName, "agent/v") {
+			return strings.TrimPrefix(r.TagName, "agent/v"), nil
+		}
+	}
+	return "", fmt.Errorf("no agent release found")
+}
+
+// DispatchUpdateAgent sends an update command to the named server's agent.
+// It fetches the latest version from Gitea and includes the download base URL.
+func DispatchUpdateAgent(serverID string) (string, error) {
+	if !Dispatcher.IsConnected(serverID) {
+		return "", fmt.Errorf("agent is not connected to the command stream")
+	}
+
+	version, err := GetLatestAgentVersion()
+	if err != nil {
+		return "", fmt.Errorf("get latest version: %w", err)
+	}
+
+	giteaHost := os.Getenv("GITEA_HOST")
+	if giteaHost == "" {
+		giteaHost = "gitea.example.com"
+	}
+
+	cmdID := uuid.New().String()
+	cmd := &pb.ServerCommand{
+		CommandId: cmdID,
+		UpdateAgent: &pb.UpdateAgentCmd{
+			Version:      version,
+			GiteaBaseURL: "https://" + giteaHost,
+		},
+	}
+	if err := Dispatcher.dispatch(serverID, cmd); err != nil {
+		return "", err
+	}
+	return version, nil
+}
+
 // DispatchDeleteKey sends a delete-key command to the named server's agent.
 // It is best-effort: if the agent is offline the local files will remain until next connection.
 func DispatchDeleteKey(serverID, label string) {

server/internal/services/servers.go

@@ -134,14 +134,18 @@ func ValidateAgentToken(serverID, agentToken string) (*models.Server, error) {
 	return &s, nil
 }
 
-func UpdateServerLastSeen(serverID string) error {
+func UpdateServerLastSeen(serverID, agentVersion string) error {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 
 	now := time.Now()
+	fields := bson.M{"last_seen": now, "status": "active"}
+	if agentVersion != "" {
+		fields["agent_version"] = agentVersion
+	}
 	_, err := db.Col("servers").UpdateOne(ctx,
 		bson.M{"server_id": serverID},
-		bson.M{"$set": bson.M{"last_seen": now, "status": "active"}},
+		bson.M{"$set": fields},
 	)
 	return err
 }