feat: create initial agent for localapi

agent/hpagent/handler.go

@@ -0,0 +1,83 @@
+package hpagent
+
+import (
+	"encoding/json"
+	"log"
+	"sync"
+	"tailscale.com/tailcfg"
+)
+
+// Represents messages from the Headplane master
+type RecvMessage struct {
+	NodeIDs []string `json:omitempty`
+}
+
+// Starts listening for messages from the Headplane master
+func (s *Socket) StartListening() {
+	for {
+		_, message, err := s.ReadMessage()
+		if err != nil {
+			log.Printf("error reading message: %v", err)
+			return
+		}
+
+		var msg RecvMessage
+		err = json.Unmarshal(message, &msg)
+		if err != nil {
+			log.Printf("error unmarshalling message: %v", err)
+			continue
+		}
+
+		if s.Debug {
+			log.Printf("got message: %s", message)
+		}
+
+		if len(msg.NodeIDs) == 0 {
+			log.Printf("got a message with no node IDs? %s", message)
+			continue
+		}
+
+		// Accumulate the results since we invoke via gofunc
+		results := make(map[string]*tailcfg.HostinfoView)
+		mu := sync.Mutex{}
+		wg := sync.WaitGroup{}
+
+		for _, nodeID := range msg.NodeIDs {
+			wg.Add(1)
+			go func(nodeID string) {
+				defer wg.Done()
+				result, err := s.Agent.GetStatusForPeer(nodeID)
+				if err != nil {
+					log.Printf("error getting status: %v", err)
+					return
+				}
+
+				if result == nil {
+					return
+				}
+
+				mu.Lock()
+				results[nodeID] = result
+				mu.Unlock()
+			}(nodeID)
+		}
+
+		wg.Wait()
+
+		// Send the results back to the Headplane master
+		err = s.SendStatus(results)
+		if err != nil {
+			log.Printf("error sending status: %v", err)
+			return
+		}
+
+		if s.Debug {
+			log.Printf("sent status: %s", results)
+		}
+	}
+}
+
+// Stops listening for messages from the Headplane master
+func (s *Socket) StopListening() {
+	s.Close()
+}

agent/hpagent/sender.go

@@ -0,0 +1,11 @@
+package hpagent
+
+import (
+	"tailscale.com/tailcfg"
+)
+
+// Sends the status to the Headplane master
+func (s *Socket) SendStatus(status map[string]*tailcfg.HostinfoView) error {
+	err := s.WriteJSON(status)
+	return err
+}

agent/hpagent/websocket.go

@@ -0,0 +1,53 @@
+package hpagent
+
+import (
+	"fmt"
+	"github.com/gorilla/websocket"
+	"github.com/tale/headplane/agent/tsnet"
+	"log"
+	"net/http"
+	"net/url"
+)
+
+type Socket struct {
+	*websocket.Conn
+	Debug bool
+	Agent *tsnet.TSAgent
+}
+
+// Creates a new websocket connection to the Headplane server.
+func NewSocket(agent *tsnet.TSAgent, controlURL string, debug bool) (*Socket, error) {
+	wsURL, err := httpToWs(controlURL)
+	if err != nil {
+		return nil, err
+	}
+
+	headers := http.Header{}
+	headers.Add("X-Headplane-TS-Node-ID", agent.ID)
+
+	log.Printf("dialing websocket at %s", wsURL)
+	ws, _, err := websocket.DefaultDialer.Dial(wsURL, headers)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Socket{ws, debug, agent}, nil
+}
+
+// We need to convert the control URL to a websocket URL
+func httpToWs(controlURL string) (string, error) {
+	u, err := url.Parse(controlURL)
+	if err != nil {
+		return "", err
+	}
+
+	if u.Scheme == "http" {
+		u.Scheme = "ws"
+	} else if u.Scheme == "https" {
+		u.Scheme = "wss"
+	} else {
+		return "", fmt.Errorf("unsupported scheme: %s", u.Scheme)
+	}
+
+	return u.String(), nil
+}