package metrics import ( "encoding/json" "fmt" "net/http" "sync" conn "github.com/cloudflare/cloudflared/connection" "github.com/rs/zerolog" ) // ReadyServer serves HTTP 200 if the tunnel can serve traffic. Intended for k8s readiness checks. type ReadyServer struct { sync.RWMutex isConnected map[int]bool log *zerolog.Logger } // NewReadyServer initializes a ReadyServer and starts listening for dis/connection events. func NewReadyServer(connectionEvents <-chan conn.Event, log *zerolog.Logger) *ReadyServer { rs := ReadyServer{ isConnected: make(map[int]bool, 0), log: log, } go func() { for c := range connectionEvents { switch c.EventType { case conn.Connected: rs.Lock() rs.isConnected[int(c.Index)] = true rs.Unlock() case conn.Disconnected, conn.Reconnecting, conn.RegisteringTunnel: rs.Lock() rs.isConnected[int(c.Index)] = false rs.Unlock() case conn.SetURL: continue default: rs.log.Error().Msgf("Unknown connection event case %v", c) } } }() return &rs } type body struct { Status int `json:"status"` ReadyConnections int `json:"readyConnections"` } // ServeHTTP responds with HTTP 200 if the tunnel is connected to the edge. func (rs *ReadyServer) ServeHTTP(w http.ResponseWriter, r *http.Request) { statusCode, readyConnections := rs.makeResponse() w.WriteHeader(statusCode) body := body{ Status: statusCode, ReadyConnections: readyConnections, } msg, err := json.Marshal(body) if err != nil { _, _ = fmt.Fprintf(w, `{"error": "%s"}`, err) } _, _ = w.Write(msg) } // This is the bulk of the logic for ServeHTTP, broken into its own pure function // to make unit testing easy. func (rs *ReadyServer) makeResponse() (statusCode, readyConnections int) { statusCode = http.StatusServiceUnavailable rs.RLock() defer rs.RUnlock() for _, connected := range rs.isConnected { if connected { statusCode = http.StatusOK readyConnections++ } } return statusCode, readyConnections }