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authorPaul Bütow <pbuetow@mimecast.com>2020-01-20 18:41:05 +0000
committerPaul Bütow <pbuetow@mimecast.com>2020-01-21 14:35:23 +0000
commitc128865c4c7411c29a59fca9a3a2f95537686d7b (patch)
tree193bccc70d942c8b70cc93fae2670263701e43aa /server/handlers/serverhandler.go
parent3755a9911ecb05886577095f2b8cc8b9e4066a3a (diff)
Move commands to cmd/ and move internal dependencies to internal/
Diffstat (limited to 'server/handlers/serverhandler.go')
-rw-r--r--server/handlers/serverhandler.go491
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
-}