Merge pull request #67 from assaf/web-tail

Web tail

src/cli/commands/tail.js

@@ -1,125 +1,28 @@
-var fs         = require('fs')
-var chalk      = require('chalk')
-var path       = require('path')
-var pathToHost = require('../utils/path-to-host')
-var config     = require('../../config.js')
+var chalk       = require('chalk')
+var Tail        = require('../../daemon/utils/tail')
+var pathToHost  = require('../utils/path-to-host')
 
 
 // Number of lines to show from end of log.
 var INITIAL_LINES = 10
 
-
-// Tail the end of the stream from the previous position.  When done, go back
-// to watching the file for changes.
-function tailStream(filename, prefix, position) {
-  var streamOptions = {
-    start:    position,
-    encoding: 'utf8'
-  }
-  var stream = fs.createReadStream(filename, streamOptions)
-
-  var lastLine = ''
-  stream.on('data', function(chunk) {
-    var buffer = lastLine + chunk
-    var lines  = buffer.split(/\n/)
-    lastLine   = lines.pop()
-    for (var i in lines) {
-      var line = lines[i] + '\n'
-      process.stdout.write(prefix + line)
-      position += line.length
-    }
-  })
-
-  stream.on('end', function() {
-    watchFile(filename, prefix, position)
-  })
-  stream.on('error', function(error) {
-    watchFile(filename, prefix, position)
-  })
-}
-
-
-// Watch file for changes.  When Katon appends to file we get a change event
-// and read from previous position forward.
-function watchFile(filename, prefix, position) {
-  try {
-    var watcher = fs.watch(filename, function(event) {
-      var stats = fs.statSync(filename)
-      if (stats.size < position) {
-        // File got truncated need to adjust position to new end of file
-        position = stats.size
-      } else if (stats.size > position) {
-        // File has more content, stop watching while we tail the stream
-        watcher.close()
-        tailStream(filename, prefix, position)
-      }
-    })
-  } catch (error) {
-    console.log(chalk.red("Cannot tail %s, start server and try again"), filename)
-    process.exit(1)
-  }
-}
-
-
-// This function dumps the end of the existing log file, and then starts
-// watching for changes.
-function tailFile(filename, prefix) {
-  var stream    = fs.createReadStream(filename, { encoding: 'utf8' })
-  var lines     = []
-  var buffer    = ''
-  var position  = 0
-  stream.on('data', function(chunk) {
-    buffer += chunk
-    // Parse stream into lines and keep the last INITIAL_LINES in memory.
-    // Make sure position points to the last byte in the file, or the first
-    // byte of the last incomplete line.
-    var match
-    while (match = buffer.match(/^.*\n/)) {
-      var line = match[0]
-      lines.push(line)
-      position += line.length
-      buffer    = buffer.slice(line.length)
-    }
-    lines = lines.slice(-INITIAL_LINES)
-  })
-  stream.on('end', function() {
-    // Dump the tail of the log to the console and start watching for changes.
-    //for (var i = 0; i < lines.length ; ++i)
-    for (var i in lines)
-      process.stdout.write(prefix + lines[i])
-    watchFile(filename, prefix, position)
-  })
-  stream.on('error', function(error) {
-    console.log(chalk.red("Cannot tail %s, start server and try again"), filename)
-    process.exit(1)
-  })
-}
-
-
-// Tail all log files from the logs directory
-function tailAllLogFiles()
-{
-  fs.readdirSync(config.logsDir)
-    .filter(function(filename) {
-      return /\.log$/.test(filename)
-    })
-    .map(function(filename) {
-      return config.logsDir + '/' + filename
+module.exports = function(args) {
+  var host  = args[0] || pathToHost(process.cwd())
+  var tail  = new Tail(host, INITIAL_LINES);
+  tail
+    .on('line', function(prefix, line) {
+      if (prefix)
+        process.stdout.write(chalk.blue('[' + prefix + ']  '))
+      process.stdout.write(line + '\n')
     })
-    .forEach(function(filename) {
-      var basename = path.basename(filename, '.log')
-      var prefix   = chalk.blue('[' + basename + ']  ')
-      tailFile(filename, prefix)
+    .on('error', function(error) {
+      process.stderr.write(chalk.red(error.message) + '\n')
+      process.exit(1)
     })
-}
-
+  tail.start()
 
-module.exports = function(args) {
-  var host    = args[0] || pathToHost(process.cwd())
-  var logFile = config.logsDir + '/' + host + '.log'
-
-  if (host == 'all')
-    tailAllLogFiles()
-  else
-    tailFile(logFile, '')
+  // Keep process running until Ctrl+C
+  setInterval(function() {
+  }, 1000)
 }
+

src/daemon/http-router.js

@@ -5,6 +5,7 @@ var address   = require('network-address')
 var chalk     = require('chalk')
 var procs     = require('./procs')
 var render    = require('./utils/render')
+var Tail      = require('./utils/tail')
 var timer     = require('./utils/timer')
 var util      = require('util')
 
@@ -73,6 +74,31 @@ function startProc(host) {
   return proc
 }
 
+function tailSSE(res) {
+  res.writeHead(200, {
+    'Content-Type':   'text/event-stream; charset=utf-8',
+    'Cache-Control':  'no-cache',
+    'Connection':     'keep-alive'
+  });
+  var tail = new Tail('all', 10)
+  tail
+    .on('line', function(prefix, line) {
+      var message = {
+        prefix: prefix,
+        line:   line.replace(/\[\d{2}m/g, '')
+      }
+      res.write('event: line\ndata: ' + JSON.stringify(message) + '\n\n');
+    })
+    .on('error', function(error) {
+      log('all', 'Cannot tail logs', error)
+    })
+  res.on('close', function() {
+    tail.stop()
+  })
+  tail.start()
+}
+
+
 module.exports.createServer = function() {
 
   var server = http.createServer()
@@ -136,10 +162,15 @@ module.exports.createServer = function() {
     // Render katon home
     var domain = getDomainId(host)
     if (domain === 'index' || domain === 'katon') {
-      return res.end(render('200.html', {
-        procs: procs.list,
-        ip: address()
-      }))
+      if (req.url == '/tail') {
+        tailSSE(res)
+        return
+      } else {
+        return res.end(render('200.html', {
+          procs: procs.list,
+          ip: address()
+        }))
+      }
     }
 
     // Verify host is set and valid

src/daemon/templates/200.html

@@ -23,4 +23,24 @@
   <% }) %>
 </table>
 
-<p><em>* xip.io is a wildcard DNS service, you can use these addresses to access your development web server from devices on your local network, like iPads, iPhones, and other computers.</em></p>
+<p><em>* xip.io is a wildcard DNS service, you can use these addresses to access your development web server from devices on your local network, like iPads, iPhones, and other computers.</em></p>
+<pre id="tail" class="pre-scrollable"></pre>
+
+<script>
+var tail   = document.getElementById('tail');
+var source = new EventSource('/tail');
+source.addEventListener('line', function(event) {
+  var message         = JSON.parse(event.data);
+  var entry           = document.createElement('div')
+  var prefix          = document.createElement('span')
+  prefix.textContent  = message.prefix + ':  '
+  prefix.className    = 'text-primary'
+  entry.appendChild(prefix)
+  var line            = document.createElement('span')
+  line.className      = 'text-nowrap'
+  line.textContent    = message.line
+  entry.appendChild(line)
+  tail.appendChild(entry)
+  tail.scrollTop      = entry.offsetTop
+});
+</script>