From fda64d8e176f4df95f82d0a7a330b517c5985aa6 Mon Sep 17 00:00:00 2001
From: John Cruz <john@barefootnetworks.com>
Date: Thu, 10 Dec 2015 16:03:24 -0800
Subject: [PATCH] Support for Docker Node.

---
 mininet/docker_node.py | 131 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)
 create mode 100755 mininet/docker_node.py

diff --git a/mininet/docker_node.py b/mininet/docker_node.py
new file mode 100755
index 00000000..5360f282
--- /dev/null
+++ b/mininet/docker_node.py
@@ -0,0 +1,131 @@
+"""
+Docker Node extends Mininet Node to enable running a Host or Switch
+inside a Docker container.
+"""
+
+import os
+import pty
+import re
+import select
+import subprocess
+import time
+
+from mininet.node import Node, Switch, Host
+from mininet.util import isShellBuiltin
+
+class DockerNode( Node ):
+    """A virtual node running in a docker container"""
+
+    def __init__( self, name, image=None, port_map=None, fs_map=None,
+                  **kwargs ):
+        if image is None:
+            raise UnboundLocalError( 'Docker image is not specified' )
+        img_id = subprocess.check_output( [ 'docker', 'images', '-q', image ] )
+        if not img_id:
+            raise ValueError( 'Docker image "%s" does not exist' % image )
+        self.docker_image = image
+        self.port_map = port_map
+        self.fs_map = fs_map
+        kwargs[ 'inNamespace' ] = True
+        Node.__init__( self, name, **kwargs )
+
+    @classmethod
+    def setup( cls ):
+        pass
+
+    def sendCmd( self, *args, **kwargs ):
+        assert self.shell and not self.waiting
+        printPid = kwargs.get( 'printPid', True )
+        # Allow sendCmd( [ list ] )
+        if len( args ) == 1 and isinstance( args[ 0 ], list ):
+            cmd = args[ 0 ]
+        # Allow sendCmd( cmd, arg1, arg2... )
+        elif len( args ) > 0:
+            cmd = args
+        # Convert to string
+        if not isinstance( cmd, str ):
+            cmd = ' '.join( [ str( c ) for c in cmd ] )
+        if not re.search( r'\w', cmd ):
+            # Replace empty commands with something harmless
+            cmd = 'echo -n'
+        self.lastCmd = cmd
+        printPid = printPid and not isShellBuiltin( cmd )
+        if len( cmd ) > 0 and cmd[ -1 ] == '&':
+            # print ^A{pid}\n{sentinel}
+            cmd += ' printf "\\001%d\\012" $! '
+        else:
+            pass
+        self.write( cmd + '\n' )
+        self.lastPid = None
+        self.waiting = True
+
+    def popen( self, *args, **kwargs ):
+        mncmd = [ 'docker', 'exec', self.name ]
+        return Node.popen( self, *args, mncmd=mncmd, **kwargs )
+
+    def stop( self, deleteIntfs=False ):
+        dev_null = open(os.devnull, 'w')
+        subprocess.call( [ 'docker rm -f ' + self.name ],
+                         stdin=dev_null, stdout=dev_null,
+                         stderr=dev_null, shell=True )
+        dev_null.close()
+        Node.stop( self, deleteIntfs )
+
+    def startShell( self, mnopts=None ):
+        self.stop()
+
+        args = ['docker', 'run', '-ti', '--rm', '--privileged=true']
+        args.extend( [ '--hostname=' + self.name, '--name=' + self.name ] )
+        args.extend( [ '-e', 'DISPLAY'] )
+        args.extend( [ '-v', '/tmp/.X11-unix:/tmp/.X11-unix:ro' ] )
+        if self.port_map is not None:
+            for p in self.port_map:
+                args.extend( [ '-p', '%d:%d' % ( p[ 0 ], p[ 1 ] ) ] )
+        if self.fs_map is not None:
+            for f in self.fs_map:
+                args.extend( [ '-v', '%s:%s' % ( f[ 0 ], f[ 1 ] ) ] )
+        args.extend( [ self.docker_image ] )
+
+        master, slave = pty.openpty()
+        self.shell = subprocess.Popen( args,
+                                       stdin=slave, stdout=slave, stderr=slave,
+                                       close_fds=True,
+                                       preexec_fn=os.setpgrp )
+        os.close( slave )
+        ttyobj = os.fdopen( master, 'rw' )
+        self.stdin = ttyobj
+        self.stdout = ttyobj
+        self.pid = self.shell.pid
+        self.pollOut = select.poll()
+        self.pollOut.register( self.stdout )
+        self.outToNode[ self.stdout.fileno() ] = self
+        self.inToNode[ self.stdin.fileno() ] = self
+        self.execed = False
+        self.lastCmd = None
+        self.lastPid = None
+        self.readbuf = ''
+        self.waiting = False
+
+        # Wait for prompt
+        time.sleep(1)
+
+        pid_cmd = ['docker', 'inspect', '--format=\'{{ .State.Pid }}\'',
+                   self.name ]
+        pidp = subprocess.Popen( pid_cmd, stdin=subprocess.PIPE,
+                                 stdout=subprocess.PIPE,
+                                 stderr=subprocess.STDOUT, close_fds=False )
+        pidp.wait()
+        ps_out = pidp.stdout.readlines()
+        self.pid = int(ps_out[0])
+        self.cmd( 'export PS1=\"\\177\"; printf "\\177"' )
+        self.cmd( 'stty -echo; set +m' )
+
+class DockerSwitch( DockerNode, Switch ):
+    """A Docker switch is a Docker Node with switch functionality"""
+    def start( self, controllers ):
+        """Start the switch"""
+        pass
+
+class DockerHost( DockerNode, Host ):
+    """A Docker host is the same as a Docker Node"""
+    pass