Merge branch 'patches/fix_bindpy' of https://github.com/cdburkard/mininet into patches/fix_bindpy

examples/bind.py

@@ -7,191 +7,33 @@ This creates hosts with private directories as desired.
 """
 
 from mininet.net import Mininet
-from mininet.node import Host
+from mininet.node import Host, HostWithPrivateDirs
 from mininet.cli import CLI
-from mininet.util import errFail, quietRun, errRun
 from mininet.topo import SingleSwitchTopo
 from mininet.log import setLogLevel, info, debug
 
-from os.path import realpath
 from functools import partial
 
 
-# Utility functions for unmounting a tree
-
-MNRUNDIR = realpath( '/var/run/mn' )
-
-def mountPoints():
-    "Return list of mounted file systems"
-    mtab, _err, _ret = errFail( 'cat /proc/mounts' )
-    lines = mtab.split( '\n' )
-    mounts = []
-    for line in lines:
-        if not line:
-            continue
-        fields = line.split( ' ')
-        mount = fields[ 1 ]
-        mounts.append( mount )
-    return mounts
-
-def unmountAll( rootdir=MNRUNDIR ):
-    "Unmount all mounts under a directory tree"
-    rootdir = realpath( rootdir )
-    # Find all mounts below rootdir
-    # This is subtle because /foo is not
-    # a parent of /foot
-    dirslash = rootdir + '/'
-    mounts = [ m for m in mountPoints()
-              if m == dir or m.find( dirslash ) == 0 ]
-    # Unmount them from bottom to top
-    mounts.sort( reverse=True )
-    for mount in mounts:
-        debug( 'Unmounting', mount, '\n' )
-        _out, err, code = errRun( 'umount', mount )
-        if code != 0:
-            info( '*** Warning: failed to umount', mount, '\n' )
-            info( err )
-
-
-class HostWithPrivateDirs( Host ):
-    "Host with private directories"
-
-    mnRunDir = MNRUNDIR
-
-    def __init__(self, name, *args, **kwargs ):
-        """privateDirs: list of private directories
-           remounts: dirs to remount
-           unmount: unmount dirs in cleanup? (True)
-           Note: if unmount is False, you must call unmountAll()
-           manually."""
-        self.privateDirs = kwargs.pop( 'privateDirs', [] )
-        self.remounts = kwargs.pop( 'remounts', [] )
-        self.unmount = kwargs.pop( 'unmount', True )
-        Host.__init__( self, name, *args, **kwargs )
-        self.rundir = '%s/%s' % ( self.mnRunDir, name )
-        self.root, self.private = None, None  # set in createBindMounts
-        if self.privateDirs:
-            self.privateDirs = [ realpath( d ) for d in self.privateDirs ]
-            self.createBindMounts()
-        # These should run in the namespace before we chroot,
-        # in order to put the right entries in /etc/mtab
-        # Eventually this will allow a local pid space
-        # Now we chroot and cd to wherever we were before.
-        pwd = self.cmd( 'pwd' ).strip()
-        self.sendCmd( 'exec chroot', self.root, 'bash -ms mininet:'
-                       + self.name )
-        self.waiting = False
-        self.cmd( 'cd', pwd )
-        # In order for many utilities to work,
-        # we need to remount /proc and /sys
-        self.cmd( 'mount /proc' )
-        self.cmd( 'mount /sys' )
-
-    def mountPrivateDirs( self ):
-        "Create and bind mount private dirs"
-        for dir_ in self.privateDirs:
-            privateDir = self.private + dir_
-            errFail( 'mkdir -p ' + privateDir )
-            mountPoint = self.root + dir_
-            errFail( 'mount -B %s %s' %
-                           ( privateDir, mountPoint) )
-
-    def mountDirs( self, dirs ):
-        "Mount a list of directories"
-        for dir_ in dirs:
-            mountpoint = self.root + dir_
-            errFail( 'mount -B %s %s' %
-                     ( dir_, mountpoint ) )
-
-    @classmethod
-    def findRemounts( cls, fstypes=None ):
-        """Identify mount points in /proc/mounts to remount
-           fstypes: file system types to match"""
-        if fstypes is None:
-            fstypes = [ 'nfs' ]
-        dirs = quietRun( 'cat /proc/mounts' ).strip().split( '\n' )
-        remounts = []
-        for dir_ in dirs:
-            line = dir_.split()
-            mountpoint, fstype = line[ 1 ], line[ 2 ]
-            # Don't re-remount directories!!!
-            if mountpoint.find( cls.mnRunDir ) == 0:
-                continue
-            if fstype in fstypes:
-                remounts.append( mountpoint )
-        return remounts
-
-    def createBindMounts( self ):
-        """Create a chroot directory structure,
-           with self.privateDirs as private dirs"""
-        errFail( 'mkdir -p '+ self.rundir )
-        unmountAll( self.rundir )
-        # Create /root and /private directories
-        self.root = self.rundir + '/root'
-        self.private = self.rundir + '/private'
-        errFail( 'mkdir -p ' + self.root )
-        errFail( 'mkdir -p ' + self.private )
-        # Recursively mount / in private doort
-        # note we'll remount /sys and /proc later
-        errFail( 'mount -B / ' + self.root )
-        self.mountDirs( self.remounts )
-        self.mountPrivateDirs()
-
-    def unmountBindMounts( self ):
-        "Unmount all of our bind mounts"
-        unmountAll( self.rundir )
-
-    def popen( self, *args, **kwargs ):
-        "Popen with chroot support"
-        chroot = kwargs.pop( 'chroot', True )
-        mncmd = kwargs.get( 'mncmd',
-                           [ 'mnexec', '-a', str( self.pid ) ] )
-        if chroot:
-            mncmd = [ 'chroot', self.root ] + mncmd
-            kwargs[ 'mncmd' ] = mncmd
-        return Host.popen( self, *args, **kwargs )
-
-    def cleanup( self ):
-        """Clean up, then unmount bind mounts
-           unmount: actually unmount bind mounts?"""
-        # Wait for process to actually terminate
-        self.shell.wait()
-        Host.cleanup( self )
-        if self.unmount:
-            self.unmountBindMounts()
-            errFail( 'rmdir ' + self.root )
-
-
-# Convenience aliases
-
-findRemounts = HostWithPrivateDirs.findRemounts
-
-
 # Sample usage
 
 def testHostWithPrivateDirs():
     "Test bind mounts"
     topo = SingleSwitchTopo( 10 )
-    remounts = findRemounts( fstypes=[ 'nfs' ] )
     privateDirs = [ '/var/log', '/var/run' ]
-    host = partial( HostWithPrivateDirs, remounts=remounts,
+    host = partial( HostWithPrivateDirs,
-                    privateDirs=privateDirs, unmount=False )
+                    privateDirs=privateDirs )
     net = Mininet( topo=topo, host=host )
     net.start()
     info( 'Private Directories:', privateDirs, '\n' )
     CLI( net )
     net.stop()
-    # We do this all at once to save a bit of time
-    info( 'Unmounting host bind mounts...\n' )
-    unmountAll()
 
 
 if __name__ == '__main__':
-    unmountAll()
     setLogLevel( 'info' )
     testHostWithPrivateDirs()
     info( 'Done.\n')
 
 
 
-

mininet/node.py

@@ -725,6 +725,23 @@ class CPULimitedHost( Host ):
         mountCgroups()
         cls.inited = True
 
+class HostWithPrivateDirs( Host ):
+    "Host with private directories"
+
+    def __init__(self, *args, **kwargs ):
+        """privateDirs: list of private directories"""
+
+        self.privateDirs = kwargs.pop( 'privateDirs', [] )
+        Host.__init__( self, *args, **kwargs )
+        self.mountPrivateDirs()
+
+    def mountPrivateDirs( self ):
+        "Mount tmpfs for each private directory"
+        for dir_ in self.privateDirs:
+            self.cmd( 'mkdir -p ' + dir_ )
+            self.cmd( 'mount -n -t tmpfs tmpfs %s' % dir_ )
+
+
 
 # Some important things to note:
 #