package diagnostic import ( "context" "encoding/json" "fmt" "net/http" "sync" "sync/atomic" "github.com/docker/docker/libnetwork/internal/caller" stackdump "github.com/docker/docker/pkg/signal" "github.com/sirupsen/logrus" ) // HTTPHandlerFunc TODO type HTTPHandlerFunc func(interface{}, http.ResponseWriter, *http.Request) type httpHandlerCustom struct { ctx interface{} F func(interface{}, http.ResponseWriter, *http.Request) } // ServeHTTP TODO func (h httpHandlerCustom) ServeHTTP(w http.ResponseWriter, r *http.Request) { h.F(h.ctx, w, r) } var diagPaths2Func = map[string]HTTPHandlerFunc{ "/": notImplemented, "/help": help, "/ready": ready, "/stackdump": stackTrace, } // Server when the debug is enabled exposes a // This data structure is protected by the Agent mutex so does not require and additional mutex here type Server struct { enable int32 srv *http.Server port int mux *http.ServeMux registeredHanders map[string]bool sync.Mutex } // New creates a new diagnostic server func New() *Server { return &Server{ registeredHanders: make(map[string]bool), } } // Init initialize the mux for the http handling and register the base hooks func (s *Server) Init() { s.mux = http.NewServeMux() // Register local handlers s.RegisterHandler(s, diagPaths2Func) } // RegisterHandler allows to register new handlers to the mux and to a specific path func (s *Server) RegisterHandler(ctx interface{}, hdlrs map[string]HTTPHandlerFunc) { s.Lock() defer s.Unlock() for path, fun := range hdlrs { if _, ok := s.registeredHanders[path]; ok { continue } s.mux.Handle(path, httpHandlerCustom{ctx, fun}) s.registeredHanders[path] = true } } // ServeHTTP this is the method called bu the ListenAndServe, and is needed to allow us to // use our custom mux func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) { s.mux.ServeHTTP(w, r) } // EnableDiagnostic opens a TCP socket to debug the passed network DB func (s *Server) EnableDiagnostic(ip string, port int) { s.Lock() defer s.Unlock() s.port = port if s.enable == 1 { logrus.Info("The server is already up and running") return } logrus.Infof("Starting the diagnostic server listening on %d for commands", port) srv := &http.Server{Addr: fmt.Sprintf("%s:%d", ip, port), Handler: s} s.srv = srv s.enable = 1 go func(n *Server) { // Ignore ErrServerClosed that is returned on the Shutdown call if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed { logrus.Errorf("ListenAndServe error: %s", err) atomic.SwapInt32(&n.enable, 0) } }(s) } // DisableDiagnostic stop the dubug and closes the tcp socket func (s *Server) DisableDiagnostic() { s.Lock() defer s.Unlock() s.srv.Shutdown(context.Background()) // nolint:errcheck s.srv = nil s.enable = 0 logrus.Info("Disabling the diagnostic server") } // IsDiagnosticEnabled returns true when the debug is enabled func (s *Server) IsDiagnosticEnabled() bool { s.Lock() defer s.Unlock() return s.enable == 1 } func notImplemented(ctx interface{}, w http.ResponseWriter, r *http.Request) { r.ParseForm() // nolint:errcheck _, json := ParseHTTPFormOptions(r) rsp := WrongCommand("not implemented", fmt.Sprintf("URL path: %s no method implemented check /help\n", r.URL.Path)) // audit logs log := logrus.WithFields(logrus.Fields{"component": "diagnostic", "remoteIP": r.RemoteAddr, "method": caller.Name(0), "url": r.URL.String()}) log.Info("command not implemented done") HTTPReply(w, rsp, json) // nolint:errcheck } func help(ctx interface{}, w http.ResponseWriter, r *http.Request) { r.ParseForm() // nolint:errcheck _, json := ParseHTTPFormOptions(r) // audit logs log := logrus.WithFields(logrus.Fields{"component": "diagnostic", "remoteIP": r.RemoteAddr, "method": caller.Name(0), "url": r.URL.String()}) log.Info("help done") n, ok := ctx.(*Server) var result string if ok { for path := range n.registeredHanders { result += fmt.Sprintf("%s\n", path) } HTTPReply(w, CommandSucceed(&StringCmd{Info: result}), json) // nolint:errcheck } } func ready(ctx interface{}, w http.ResponseWriter, r *http.Request) { r.ParseForm() // nolint:errcheck _, json := ParseHTTPFormOptions(r) // audit logs log := logrus.WithFields(logrus.Fields{"component": "diagnostic", "remoteIP": r.RemoteAddr, "method": caller.Name(0), "url": r.URL.String()}) log.Info("ready done") HTTPReply(w, CommandSucceed(&StringCmd{Info: "OK"}), json) // nolint:errcheck } func stackTrace(ctx interface{}, w http.ResponseWriter, r *http.Request) { r.ParseForm() // nolint:errcheck _, json := ParseHTTPFormOptions(r) // audit logs log := logrus.WithFields(logrus.Fields{"component": "diagnostic", "remoteIP": r.RemoteAddr, "method": caller.Name(0), "url": r.URL.String()}) log.Info("stack trace") path, err := stackdump.DumpStacks("/tmp/") if err != nil { log.WithError(err).Error("failed to write goroutines dump") HTTPReply(w, FailCommand(err), json) // nolint:errcheck } else { log.Info("stack trace done") HTTPReply(w, CommandSucceed(&StringCmd{Info: fmt.Sprintf("goroutine stacks written to %s", path)}), json) // nolint:errcheck } } // DebugHTTPForm helper to print the form url parameters func DebugHTTPForm(r *http.Request) { for k, v := range r.Form { logrus.Debugf("Form[%q] = %q\n", k, v) } } // JSONOutput contains details on JSON output printing type JSONOutput struct { enable bool prettyPrint bool } // ParseHTTPFormOptions easily parse the JSON printing options func ParseHTTPFormOptions(r *http.Request) (bool, *JSONOutput) { _, unsafe := r.Form["unsafe"] v, json := r.Form["json"] var pretty bool if len(v) > 0 { pretty = v[0] == "pretty" } return unsafe, &JSONOutput{enable: json, prettyPrint: pretty} } // HTTPReply helper function that takes care of sending the message out func HTTPReply(w http.ResponseWriter, r *HTTPResult, j *JSONOutput) (int, error) { var response []byte if j.enable { w.Header().Set("Content-Type", "application/json") var err error if j.prettyPrint { response, err = json.MarshalIndent(r, "", " ") if err != nil { response, _ = json.MarshalIndent(FailCommand(err), "", " ") } } else { response, err = json.Marshal(r) if err != nil { response, _ = json.Marshal(FailCommand(err)) } } } else { response = []byte(r.String()) } return fmt.Fprint(w, string(response)) }