feat: initial commit

internal/server/handlers_agent.go

@@ -0,0 +1,127 @@
+package server
+
+import (
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"github.com/x-grk/longpolling-remote-access/internal/proto"
+)
+
+// Long-poll hold window. Must stay below nginx proxy_read_timeout (120s).
+const pollHold = 25 * time.Second
+
+func writeJSON(w http.ResponseWriter, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(v)
+}
+
+// POST /api/agent/enroll — exchange the shared enroll secret for a per-agent id+token.
+func (s *Server) handleEnroll(w http.ResponseWriter, r *http.Request) {
+	secret := r.Header.Get("X-Enroll-Secret")
+	if !constantTimeEqual(secret, s.db.EnrollSecret()) {
+		http.Error(w, "forbidden", http.StatusForbidden)
+		return
+	}
+	var req proto.EnrollRequest
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<16)).Decode(&req); err != nil {
+		http.Error(w, "bad request", http.StatusBadRequest)
+		return
+	}
+	id, token, err := s.enroll(req.Name, req.Hostname, req.OS, req.Arch, req.Version)
+	if err != nil {
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+	writeJSON(w, proto.EnrollResponse{AgentID: id, Token: token})
+}
+
+// GET /api/agent/poll — control channel. Held until a job is queued or timeout.
+func (s *Server) handlePoll(w http.ResponseWriter, r *http.Request) {
+	a := s.authenticateAgent(r)
+	if a == nil {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+	// The agent sends its version occasionally; record it when present.
+	if v := r.Header.Get("X-Agent-Version"); v != "" && v != a.Version {
+		_ = s.db.TouchAgentVersion(a.ID, v)
+	} else {
+		_ = s.db.TouchAgent(a.ID)
+	}
+	writeJSON(w, s.hub.WaitControl(a.ID, pollHold))
+}
+
+// GET /api/agent/task/{id} — the agent fetches the task to run.
+func (s *Server) handleTaskFetch(w http.ResponseWriter, r *http.Request) {
+	if s.authenticateAgent(r) == nil {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+	env, ok := s.hub.GetTask(r.PathValue("id"))
+	if !ok {
+		http.Error(w, "no task", http.StatusGone)
+		return
+	}
+	writeJSON(w, env)
+}
+
+// POST /api/agent/task/{id}/result — the agent returns the task result.
+func (s *Server) handleTaskResult(w http.ResponseWriter, r *http.Request) {
+	if s.authenticateAgent(r) == nil {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+	var res proto.TaskResult
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 64<<20)).Decode(&res); err != nil {
+		http.Error(w, "bad request", http.StatusBadRequest)
+		return
+	}
+	s.hub.CompleteTask(r.PathValue("id"), res)
+	w.WriteHeader(http.StatusNoContent)
+}
+
+// GET /api/agent/term/{sid}/in — downstream (panel -> agent) long-poll.
+func (s *Server) handleTermIn(w http.ResponseWriter, r *http.Request) {
+	if s.authenticateAgent(r) == nil {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+	sess := s.hub.Session(r.PathValue("sid"))
+	if sess == nil {
+		http.Error(w, "no session", http.StatusGone)
+		return
+	}
+	frames, alive := sess.PollIn(pollHold)
+	if !alive {
+		http.Error(w, "closed", http.StatusGone)
+		return
+	}
+	writeJSON(w, proto.InBatch{Frames: frames})
+}
+
+// POST /api/agent/term/{sid}/out — upstream (agent PTY -> panel).
+func (s *Server) handleTermOut(w http.ResponseWriter, r *http.Request) {
+	if s.authenticateAgent(r) == nil {
+		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		return
+	}
+	sess := s.hub.Session(r.PathValue("sid"))
+	if sess == nil {
+		http.Error(w, "no session", http.StatusGone)
+		return
+	}
+	var msg proto.OutMessage
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<20)).Decode(&msg); err != nil {
+		http.Error(w, "bad request", http.StatusBadRequest)
+		return
+	}
+	if !sess.PushOut(msg) {
+		http.Error(w, "closed", http.StatusGone)
+		return
+	}
+	if msg.Exit {
+		s.hub.CloseSession(sess.ID)
+	}
+	w.WriteHeader(http.StatusNoContent)
+}