diff options
| author | Paul Bütow <pbuetow@mimecast.com> | 2020-01-20 18:41:05 +0000 |
|---|---|---|
| committer | Paul Bütow <pbuetow@mimecast.com> | 2020-01-21 14:35:23 +0000 |
| commit | c128865c4c7411c29a59fca9a3a2f95537686d7b (patch) | |
| tree | 193bccc70d942c8b70cc93fae2670263701e43aa /server/handlers/serverhandler.go | |
| parent | 3755a9911ecb05886577095f2b8cc8b9e4066a3a (diff) | |
Move commands to cmd/ and move internal dependencies to internal/
Diffstat (limited to 'server/handlers/serverhandler.go')
| -rw-r--r-- | server/handlers/serverhandler.go | 491 |
1 files changed, 0 insertions, 491 deletions
diff --git a/server/handlers/serverhandler.go b/server/handlers/serverhandler.go deleted file mode 100644 index e2466d4..0000000 --- a/server/handlers/serverhandler.go +++ /dev/null @@ -1,491 +0,0 @@ -package handlers - -import ( - "dtail/config" - "dtail/fs" - "dtail/logger" - "dtail/mapr/server" - "dtail/omode" - "dtail/server/user" - "dtail/version" - "fmt" - "io" - "os" - "path/filepath" - "strings" - "sync" - "time" -) - -const ( - commandParseWarning string = "Unable to parse command" -) - -// ServerHandler implements the Reader and Writer interfaces to handle -// the Bi-directional communication between SSH client and server. -// This handler implements the handler of the SSH server. -type ServerHandler struct { - // Local log file readers - fileReaders []fs.FileReader - fileReadersMtx *sync.Mutex - // Channel for read lines. - lines chan fs.LineRead - // Only process log lines matching this regex. - regex string - // Server side mapr log aggregation. - aggregate *server.Aggregate - // Channel of aggregated log lines. - aggregatedMessages chan string - // Channel for server messages to be sent to the client. - serverMessages chan string - // Channel for hidden messages to be sent to the client. - hiddenMessages chan string - // The current payload sent to the client. - payload []byte - // The current server hostname. - hostname string - // The user connecting to dtail. - user *user.User - // To limit the server wide max amount of concurrent cats - catLimiter chan struct{} - // To limit the server wide max amount of concurrent tails - tailLimiter chan struct{} - // Server can tell handler to stop the handler. - stop chan struct{} - // Indicate that client responded to server with "ack stop connection" - ackStopReceived chan struct{} - // Stop timeout. - stopTimeout chan struct{} -} - -// NewServerHandler returns the server handler. -func NewServerHandler(user *user.User, catLimiter chan struct{}, tailLimiter chan struct{}) *ServerHandler { - logger.Debug(user, "Creating tail handler") - h := ServerHandler{ - fileReadersMtx: &sync.Mutex{}, - lines: make(chan fs.LineRead, 100), - serverMessages: make(chan string, 10), - aggregatedMessages: make(chan string, 10), - hiddenMessages: make(chan string, 10), - ackStopReceived: make(chan struct{}), - stopTimeout: make(chan struct{}), - stop: make(chan struct{}), - catLimiter: catLimiter, - tailLimiter: tailLimiter, - regex: ".", - user: user, - } - - fqdn, err := os.Hostname() - if err != nil { - logger.FatalExit(err) - } - - s := strings.Split(fqdn, ".") - h.hostname = s[0] - - return &h -} - -// Read is to send data to the dtail client via Reader interface. -func (h *ServerHandler) Read(p []byte) (n int, err error) { - for { - select { - case message := <-h.serverMessages: - wholePayload := []byte(fmt.Sprintf("SERVER|%s|%s\n", h.hostname, message)) - n = copy(p, wholePayload) - return - case message := <-h.aggregatedMessages: - data := fmt.Sprintf("AGGREGATE|%s|%s\n", h.hostname, message) - //logger.Debug("Sending aggregation data", data) - wholePayload := []byte(data) - n = copy(p, wholePayload) - return - case message := <-h.hiddenMessages: - //logger.Debug(h.user, "Sending hidden message", message) - wholePayload := []byte(fmt.Sprintf(".%s\n", message)) - n = copy(p, wholePayload) - return - case line := <-h.lines: - serverInfo := []byte(fmt.Sprintf("REMOTE|%s|%3d|%v|%s|", - h.hostname, line.TransmittedPerc, line.Count, *line.GlobID)) - wholePayload := append(serverInfo, line.Content[:]...) - n = copy(p, wholePayload) - return - case <-time.After(time.Second): - select { - case <-h.stop: - return 0, io.EOF - default: - } - } - } -} - -// Write is to receive data from the dtail client via Writer interface. -func (h *ServerHandler) Write(p []byte) (n int, err error) { - for _, c := range p { - switch c { - case ';': - commandStr := strings.TrimSpace(string(h.payload)) - h.handleCommand(commandStr) - h.payload = nil - default: - h.payload = append(h.payload, c) - } - } - - n = len(p) - return -} - -// Close the server handler. -func (h *ServerHandler) Close() { - h.fileReadersMtx.Lock() - defer h.fileReadersMtx.Unlock() - - for _, reader := range h.fileReaders { - reader.Stop() - } - if h.aggregate != nil { - h.aggregate.Close() - } - - close(h.stop) -} - -func (h *ServerHandler) makeGlobID(path, glob string) string { - var idParts []string - pathParts := strings.Split(path, "/") - - for i, globPart := range strings.Split(glob, "/") { - if strings.Contains(globPart, "*") { - idParts = append(idParts, pathParts[i]) - } - } - - if len(idParts) > 0 { - return strings.Join(idParts, "/") - } - - if len(pathParts) > 0 { - return pathParts[len(pathParts)-1] - } - - h.send(h.serverMessages, logger.Error("Empty file path given?", path, glob)) - return "" -} - -func (h *ServerHandler) processFileGlob(mode omode.Mode, glob string, regex string) { - retryInterval := time.Second * 5 - glob = filepath.Clean(glob) - - errors := make(chan struct{}) - stop := make(chan struct{}) - defer close(stop) - - go func() { - for { - select { - case <-errors: - h.send(h.serverMessages, logger.Warn(h.user, "Unable to read file(s), check server logs")) - case <-stop: - return - case <-h.stop: - return - } - } - }() - - maxRetries := 10 - for { - maxRetries-- - if maxRetries < 0 { - h.send(h.serverMessages, logger.Warn(h.user, "Giving up to read file(s)")) - h.internalClose() - return - } - - paths, err := filepath.Glob(glob) - if err != nil { - logger.Warn(h.user, glob, err) - time.Sleep(retryInterval) - continue - } - - if numPaths := len(paths); numPaths == 0 { - logger.Error(h.user, "No such file(s) to read", glob) - select { - case errors <- struct{}{}: - case <-h.stop: - return - default: - } - time.Sleep(retryInterval) - continue - } - - h.startReadingFiles(mode, paths, glob, regex, retryInterval, errors) - break - } -} - -func (h *ServerHandler) startReadingFiles(mode omode.Mode, paths []string, glob string, regex string, retryInterval time.Duration, errors chan<- struct{}) { - var wg sync.WaitGroup - wg.Add(len(paths)) - - read := func(path string, wg *sync.WaitGroup) { - defer wg.Done() - globID := h.makeGlobID(path, glob) - - if !h.user.HasFilePermission(path) { - logger.Error(h.user, "No permission to read file", path, globID) - select { - case errors <- struct{}{}: - default: - } - return - } - - h.startReadingFile(mode, path, globID, regex) - } - - for _, path := range paths { - go read(path, &wg) - } - - wg.Wait() -} - -func (h *ServerHandler) startReadingFile(mode omode.Mode, path, globID, regex string) { - defer h.stopReadingFile(path) - logger.Info(h.user, "Start reading file", path, globID) - - var reader fs.FileReader - switch mode { - case omode.TailClient: - reader = fs.NewTailFile(path, globID, h.serverMessages, h.tailLimiter) - case omode.GrepClient: - fallthrough - case omode.CatClient: - reader = fs.NewCatFile(path, globID, h.serverMessages, h.catLimiter) - default: - reader = fs.NewTailFile(path, globID, h.serverMessages, h.tailLimiter) - } - - h.fileReadersMtx.Lock() - h.fileReaders = append(h.fileReaders, reader) - h.fileReadersMtx.Unlock() - - lines := h.lines - // Plugin mappreduce engine - if h.aggregate != nil { - lines = h.aggregate.Lines - } - - for { - if err := reader.Start(lines, regex); err != nil { - logger.Error(h.user, path, globID, err) - } - - select { - case <-h.stop: - return - default: - if !reader.Retry() { - return - } - } - - time.Sleep(time.Second * 2) - logger.Info(path, globID, "Reading file again") - } -} - -func (h *ServerHandler) stopReadingFile(path string) { - logger.Info(h.user, "Stop reading file", path) - - h.fileReadersMtx.Lock() - defer h.fileReadersMtx.Unlock() - - path = filepath.Clean(path) - var fileReaders []fs.FileReader - - for _, reader := range h.fileReaders { - if reader.FilePath() == path { - reader.Stop() - continue - } - fileReaders = append(fileReaders, reader) - } - - if len(fileReaders) == len(h.fileReaders) { - logger.Warn(h.user, "Didn't read file path", path) - return - } - - h.fileReaders = fileReaders - - if len(fileReaders) == 0 { - if h.aggregate != nil { - h.aggregate.Serialize() - } - h.allLinesSent() - } -} - -func (h *ServerHandler) numUnsentMessages() int { - return len(h.lines) + len(h.serverMessages) + len(h.hiddenMessages) + len(h.aggregatedMessages) -} - -func (h *ServerHandler) allLinesSent() { - defer h.internalClose() - - for i := 0; i < 3; i++ { - if h.numUnsentMessages() == 0 { - logger.Debug(h.user, "All lines sent") - return - } - logger.Debug(h.user, "Still lines to be sent") - time.Sleep(time.Second) - } - - logger.Warn(h.user, "Some lines remain unsent", h.numUnsentMessages()) -} - -// Handler decides to shutdown the connection, not the server itself. -func (h *ServerHandler) internalClose() { - select { - case h.hiddenMessages <- "syn close connection": - case <-time.After(time.Second * 5): - logger.Debug(h.user, "Not waiting for ack close connection") - close(h.stopTimeout) - return - } - - select { - case <-h.Wait(): - case <-time.After(time.Second * 5): - logger.Debug(h.user, "Not waiting for ack close connection") - close(h.stopTimeout) - } -} - -func (h *ServerHandler) handleCommand(commandStr string) { - logger.Info(h.user, commandStr) - - args := strings.Split(commandStr, " ") - argc := len(args) - - logger.Debug(h.user, "Received command", commandStr, argc, args) - - if h.user.Name == config.ControlUser { - h.handleControlCommand(argc, args) - return - } - - h.handleUserCommand(argc, args) -} - -// Special (restricted) set of commands for anonymous ControlUser access. -func (h *ServerHandler) handleControlCommand(argc int, args []string) { - switch args[0] { - case "ping": - h.send(h.hiddenMessages, "pong") - case "debug": - h.send(h.serverMessages, logger.Debug(h.user, "Receiving debug command", argc, args)) - default: - logger.Warn(h.user, "Received unknown command", argc, args) - } -} - -// Commands for authed users. -func (h *ServerHandler) handleUserCommand(argc int, args []string) { - switch args[0] { - case "grep": - fallthrough - case "cat": - h.handleReadCommand(argc, args, omode.CatClient) - case "tail": - h.handleReadCommand(argc, args, omode.TailClient) - case "map": - h.handleMapCommand(argc, args) - case "ack": - h.handleAckCommand(argc, args) - case "ping": - h.send(h.hiddenMessages, "pong") - case "version": - h.send(h.serverMessages, fmt.Sprintf("Server version is "+version.String())) - case "debug": - h.send(h.serverMessages, logger.Debug(h.user, "Received debug command", argc, args)) - default: - h.send(h.serverMessages, logger.Warn(h.user, "Received unknown command", argc, args)) - } -} - -func (h *ServerHandler) handleReadCommand(argc int, args []string, mode omode.Mode) { - regex := "." - if argc >= 4 { - regex = args[3] - } - if argc < 3 { - h.send(h.serverMessages, logger.Warn(h.user, commandParseWarning, args, argc)) - return - } - go h.processFileGlob(mode, args[1], regex) -} - -func (h *ServerHandler) handleMapCommand(argc int, args []string) { - if argc < 2 { - h.send(h.serverMessages, logger.Warn(h.user, commandParseWarning, args, argc)) - return - } - - queryStr := strings.Join(args[1:], " ") - logger.Info(h.user, "Creating new mapr aggregator", queryStr) - aggregate, err := server.NewAggregate(h.aggregatedMessages, queryStr) - - if err != nil { - h.send(h.serverMessages, logger.Error(h.user, err)) - return - } - - h.aggregate = aggregate -} - -func (h *ServerHandler) handleAckCommand(argc int, args []string) { - if argc < 3 { - h.send(h.serverMessages, logger.Warn(h.user, commandParseWarning, args, argc)) - return - } - if args[1] == "close" && args[2] == "connection" { - close(h.ackStopReceived) - } -} - -func (h *ServerHandler) send(ch chan<- string, message string) { - select { - case ch <- message: - case <-h.stop: - } -} - -// Wait (block) until server handler is closed or a timeout has exceeded. -func (h *ServerHandler) Wait() <-chan struct{} { - wait := make(chan struct{}) - - go func() { - select { - case <-h.ackStopReceived: - logger.Debug(h.user, "Closing wait channel due to ACK stop received") - close(wait) - case <-h.stopTimeout: - logger.Debug(h.user, "Closing wait channel due to wait timeout") - close(wait) - case <-h.stop: - logger.Debug(h.user, "Closing wait channel due to stop") - } - }() - - return wait -} |
