Adding trace Collector RM
[nepi.git] / src / nepi / resources / linux / node.py
index 8387def..0d2597f 100644 (file)
 # Author: Alina Quereilhac <alina.quereilhac@inria.fr>
 
 from nepi.execution.attribute import Attribute, Flags
-from nepi.execution.resource import ResourceManager, clsinit, ResourceState
+from nepi.execution.resource import ResourceManager, clsinit, ResourceState, \
+        reschedule_delay
 from nepi.resources.linux import rpmfuncs, debfuncs 
-from nepi.util import sshfuncs, execfuncs 
+from nepi.util import sshfuncs, execfuncs
+from nepi.util.sshfuncs import ProcStatus
 
 import collections
 import os
@@ -35,11 +37,112 @@ import threading
 # TODO: Unify delays!!
 # TODO: Validate outcome of uploads!! 
 
-reschedule_delay = "0.5s"
 
+class ExitCode:
+    """
+    Error codes that the rexitcode function can return if unable to
+    check the exit code of a spawned process
+    """
+    FILENOTFOUND = -1
+    CORRUPTFILE = -2
+    ERROR = -3
+    OK = 0
+
+class OSType:
+    """
+    Supported flavors of Linux OS
+    """
+    FEDORA_8 = "f8"
+    FEDORA_12 = "f12"
+    FEDORA_14 = "f14"
+    FEDORA = "fedora"
+    UBUNTU = "ubuntu"
+    DEBIAN = "debian"
 
 @clsinit
 class LinuxNode(ResourceManager):
+    """
+    .. class:: Class Args :
+      
+        :param ec: The Experiment controller
+        :type ec: ExperimentController
+        :param guid: guid of the RM
+        :type guid: int
+
+    .. note::
+
+        There are different ways in which commands can be executed using the
+        LinuxNode interface (i.e. 'execute' - blocking and non blocking, 'run',
+        'run_and_wait'). 
+        
+        Brief explanation:
+
+            * 'execute' (blocking mode) :  
+
+                     HOW IT WORKS: 'execute', forks a process and run the
+                     command, synchronously, attached to the terminal, in
+                     foreground.
+                     The execute method will block until the command returns
+                     the result on 'out', 'err' (so until it finishes executing).
+  
+                     USAGE: short-lived commands that must be executed attached
+                     to a terminal and in foreground, for which it IS necessary
+                     to block until the command has finished (e.g. if you want
+                     to run 'ls' or 'cat').
+
+            * 'execute' (NON blocking mode - blocking = False) :
+
+                    HOW IT WORKS: Same as before, except that execute method
+                    will return immediately (even if command still running).
+
+                    USAGE: long-lived commands that must be executed attached
+                    to a terminal and in foreground, but for which it is not
+                    necessary to block until the command has finished. (e.g.
+                    start an application using X11 forwarding)
+
+             * 'run' :
+
+                   HOW IT WORKS: Connects to the host ( using SSH if remote)
+                   and launches the command in background, detached from any
+                   terminal (daemonized), and returns. The command continues to
+                   run remotely, but since it is detached from the terminal,
+                   its pipes (stdin, stdout, stderr) can't be redirected to the
+                   console (as normal non detached processes would), and so they
+                   are explicitly redirected to files. The pidfile is created as
+                   part of the process of launching the command. The pidfile
+                   holds the pid and ppid of the process forked in background,
+                   so later on it is possible to check whether the command is still
+                   running.
+
+                    USAGE: long-lived commands that can run detached in background,
+                    for which it is NOT necessary to block (wait) until the command
+                    has finished. (e.g. start an application that is not using X11
+                    forwarding. It can run detached and remotely in background)
+
+             * 'run_and_wait' :
+
+                    HOW IT WORKS: Similar to 'run' except that it 'blocks' until
+                    the command has finished execution. It also checks whether
+                    errors occurred during runtime by reading the exitcode file,
+                    which contains the exit code of the command that was run
+                    (checking stderr only is not always reliable since many
+                    commands throw debugging info to stderr and the only way to
+                    automatically know whether an error really happened is to
+                    check the process exit code).
+
+                    Another difference with respect to 'run', is that instead
+                    of directly executing the command as a bash command line,
+                    it uploads the command to a bash script and runs the script.
+                    This allows to use the bash script to debug errors, since
+                    it remains at the remote host and can be run manually to
+                    reproduce the error.
+                  
+                    USAGE: medium-lived commands that can run detached in
+                    background, for which it IS necessary to block (wait) until
+                    the command has finished. (e.g. Package installation,
+                    source compilation, file download, etc)
+
+    """
     _rtype = "LinuxNode"
 
     @classmethod
@@ -125,14 +228,16 @@ class LinuxNode(ResourceManager):
             self.error(msg, out, err)
             raise RuntimeError, "%s - %s - %s" %( msg, out, err )
 
-        if out.find("Fedora release 12") == 0:
-            self._os = "f12"
+        if out.find("Fedora release 8") == 0:
+            self._os = OSType.FEDORA_8
+        elif out.find("Fedora release 12") == 0:
+            self._os = OSType.FEDORA_12
         elif out.find("Fedora release 14") == 0:
-            self._os = "f14"
+            self._os = OSType.FEDORA_14
         elif out.find("Debian") == 0: 
-            self._os = "debian"
+            self._os = OSType.DEBIAN
         elif out.find("Ubuntu") ==0:
-            self._os = "ubuntu"
+            self._os = OSType.UBUNTU
         else:
             msg = "Unsupported OS"
             self.error(msg, out)
@@ -140,6 +245,15 @@ class LinuxNode(ResourceManager):
 
         return self._os
 
+    @property
+    def use_deb(self):
+        return self.os in [OSType.DEBIAN, OSType.UBUNTU]
+
+    @property
+    def use_rpm(self):
+        return self.os in [OSType.FEDORA_12, OSType.FEDORA_14, OSType.FEDORA_8,
+                OSType.FEDORA]
+
     @property
     def localhost(self):
         return self.get("hostname") in ['localhost', '127.0.0.7', '::1']
@@ -164,8 +278,8 @@ class LinuxNode(ResourceManager):
     def deploy(self):
         if self.state == ResourceState.NEW:
             try:
-               self.discover()
-               self.provision()
+                self.discover()
+                self.provision()
             except:
                 self._state = ResourceState.FAILED
                 raise
@@ -249,7 +363,6 @@ class LinuxNode(ResourceManager):
         if not self.localhost:
             # Build destination as <user>@<server>:<path>
             dst = "%s@%s:%s" % (self.get("username"), self.get("hostname"), dst)
-
         result = self.copy(src, dst)
 
         # clean up temp file
@@ -264,46 +377,46 @@ class LinuxNode(ResourceManager):
             src = "%s@%s:%s" % (self.get("username"), self.get("hostname"), src)
         return self.copy(src, dst)
 
-    def install_packages(self, packages, home = None):
-        home = home or self.node_home
-
-        cmd = ""
-        if self.os in ["f12", "f14"]:
-            cmd = rpmfuncs.install_packages_command(self.os, packages)
-        elif self.os in ["debian", "ubuntu"]:
-            cmd = debfuncs.install_packages_command(self.os, packages)
+    def install_packages(self, packages, home):
+        command = ""
+        if self.use_rpm:
+            command = rpmfuncs.install_packages_command(self.os, packages)
+        elif self.use_deb:
+            command = debfuncs.install_packages_command(self.os, packages)
         else:
             msg = "Error installing packages ( OS not known ) "
             self.error(msg, self.os)
             raise RuntimeError, msg
 
         out = err = ""
-        (out, err), proc = self.run_and_wait(cmd, home, 
-            pidfile = "instpkg_pid",
-            stdout = "instpkg_out", 
-            stderr = "instpkg_err",
+        (out, err), proc = self.run_and_wait(command, home, 
+            shfile = "instpkg.sh",
+            pidfile = "instpkg_pidfile",
+            ecodefile = "instpkg_exitcode",
+            stdout = "instpkg_stdout", 
+            stderr = "instpkg_stderr",
             raise_on_error = True)
 
         return (out, err), proc 
 
-    def remove_packages(self, packages, home = None):
-        home = home or self.node_home
-
-        cmd = ""
-        if self.os in ["f12", "f14"]:
-            cmd = rpmfuncs.remove_packages_command(self.os, packages)
-        elif self.os in ["debian", "ubuntu"]:
-            cmd = debfuncs.remove_packages_command(self.os, packages)
+    def remove_packages(self, packages, home):
+        command = ""
+        if self.use_rpm:
+            command = rpmfuncs.remove_packages_command(self.os, packages)
+        elif self.use_deb:
+            command = debfuncs.remove_packages_command(self.os, packages)
         else:
             msg = "Error removing packages ( OS not known ) "
             self.error(msg)
             raise RuntimeError, msg
 
         out = err = ""
-        (out, err), proc = self.run_and_wait(cmd, home, 
-            pidfile = "rmpkg_pid",
-            stdout = "rmpkg_out", 
-            stderr = "rmpkg_err",
+        (out, err), proc = self.run_and_wait(command, home, 
+            shfile = "rmpkg.sh",
+            pidfile = "rmpkg_pidfile",
+            ecodefile = "rmpkg_exitcode",
+            stdout = "rmpkg_stdout", 
+            stderr = "rmpkg_stderr",
             raise_on_error = True)
          
         return (out, err), proc 
@@ -316,22 +429,29 @@ class LinuxNode(ResourceManager):
 
     def rmdir(self, path):
         return self.execute("rm -rf %s" % path, with_lock = True)
-
-    def run_and_wait(self, command, 
-            home = ".", 
-            pidfile = "pid", 
+        
+    def run_and_wait(self, command, home, 
+            shfile = "cmd.sh",
+            env = None,
+            pidfile = "pidfile", 
+            ecodefile = "exitcode", 
             stdin = None, 
-            stdout = 'stdout'
-            stderr = 'stderr'
+            stdout = "stdout"
+            stderr = "stderr"
             sudo = False,
             tty = False,
             raise_on_error = False):
-        """ runs a command in background on the remote host, but waits
-            until the command finishes execution.
-            This is more robust than doing a simple synchronized 'execute',
-            since in the remote host the command can continue to run detached
-            even if network disconnections occur
         """
+        Uploads the 'command' to a bash script in the host.
+        Then runs the script detached in background in the host, and
+        busy-waites until the script finishes executing.
+        """
+        self.upload_command(command, home, 
+            shfile = shfile, 
+            ecodefile = ecodefile, 
+            env = env)
+
+        command = "bash ./%s" % shfile
         # run command in background in remote host
         (out, err), proc = self.run(command, home, 
                 pidfile = pidfile,
@@ -342,7 +462,7 @@ class LinuxNode(ResourceManager):
                 tty = tty)
 
         # check no errors occurred
-        if proc.poll() and err:
+        if proc.poll():
             msg = " Failed to run command '%s' " % command
             self.error(msg, out, err)
             if raise_on_error:
@@ -356,11 +476,14 @@ class LinuxNode(ResourceManager):
 
         # wait until command finishes to execute
         self.wait_run(pid, ppid)
-       
-        # check if execution errors occurred
-        (out, err), proc = self.check_output(home, stderr)
-
-        if err or out:
+      
+        (out, err), proc = self.check_errors(home,
+            ecodefile = ecodefile,
+            stdout = stdout,
+            stderr= stderr)
+
+        # Out is what was written in the stderr file
+        if err:
             msg = " Failed to run command '%s' " % command
             self.error(msg, out, err)
 
@@ -368,21 +491,117 @@ class LinuxNode(ResourceManager):
                 raise RuntimeError, msg
         
         return (out, err), proc
+
+    def exitcode(self, home, ecodefile = "exitcode"):
+        """
+        Get the exit code of an application.
+        Returns an integer value with the exit code 
+        """
+        (out, err), proc = self.check_output(home, ecodefile)
+
+        # Succeeded to open file, return exit code in the file
+        if proc.wait() == 0:
+            try:
+                return int(out.strip())
+            except:
+                # Error in the content of the file!
+                return ExitCode.CORRUPTFILE
+
+        # No such file or directory
+        if proc.returncode == 1:
+            return ExitCode.FILENOTFOUND
+        
+        # Other error from 'cat'
+        return ExitCode.ERROR
+
+    def upload_command(self, command, home, 
+            shfile = "cmd.sh",
+            ecodefile = "exitcode",
+            env = None):
+        """ Saves the command as a bash script file in the remote host, and
+        forces to save the exit code of the command execution to the ecodefile
+        """
+
+        if not (command.strip().endswith(";") or command.strip().endswith("&")):
+            command += ";"
+      
+        # The exit code of the command will be stored in ecodefile
+        command = " { %(command)s } ; echo $? > %(ecodefile)s ;" % {
+                'command': command,
+                'ecodefile': ecodefile,
+                } 
+
+        # Export environment
+        environ = self.format_environment(env)
+
+        # Add environ to command
+        command = environ + command
+
+        dst = os.path.join(home, shfile)
+        return self.upload(command, dst, text = True)
+
+    def format_environment(self, env, inline = False):
+        """Format environmental variables for command to be executed either
+        as an inline command
+        (i.e. export PYTHONPATH=src/..; export LALAL= ..;python script.py) or 
+        as a bash script (i.e. export PYTHONPATH=src/.. \n export LALA=.. \n)
+        """
+        if not env: return ""
+
+        # Remove extra white spaces
+        env = re.sub(r'\s+', ' ', env.strip())
+
+        sep = ";" if inline else "\n"
+        return sep.join(map(lambda e: " export %s" % e, env.split(" "))) + sep 
+
+    def check_errors(self, home, 
+            ecodefile = "exitcode", 
+            stdout = "stdout",
+            stderr = "stderr"):
+        """
+        Checks whether errors occurred while running a command.
+        It first checks the exit code for the command, and only if the
+        exit code is an error one it returns the error output.
+
+        """
+        proc = None
+        err = ""
+        # retrive standard output from the file
+        (out, oerr), oproc = self.check_output(home, stdout)
+
+        # get exit code saved in the 'exitcode' file
+        ecode = self.exitcode(home, ecodefile)
+
+        if ecode in [ ExitCode.CORRUPTFILE, ExitCode.ERROR ]:
+            err = "Error retrieving exit code status from file %s/%s" % (home, ecodefile)
+        elif ecode > 0 or ecode == ExitCode.FILENOTFOUND:
+            # The process returned an error code or didn't exist. 
+            # Check standard error.
+            (err, eerr), proc = self.check_output(home, stderr)
+
+            # If the stderr file was not found, assume nothing bad happened,
+            # and just ignore the error.
+            # (cat returns 1 for error "No such file or directory")
+            if ecode == ExitCode.FILENOTFOUND and proc.poll() == 1: 
+                err = "" 
+            
+        return (out, err), proc
  
-    def wait_pid(self, home = ".", pidfile = "pid", raise_on_error = False):
+    def wait_pid(self, home, pidfile = "pidfile", raise_on_error = False):
         """ Waits until the pid file for the command is generated, 
             and returns the pid and ppid of the process """
         pid = ppid = None
         delay = 1.0
-        for i in xrange(5):
-            pidtuple = self.checkpid(home = home, pidfile = pidfile)
+
+        for i in xrange(4):
+            pidtuple = self.getpid(home = home, pidfile = pidfile)
             
             if pidtuple:
                 pid, ppid = pidtuple
                 break
             else:
                 time.sleep(delay)
-                delay = min(30,delay*1.2)
+                delay = delay * 1.5
         else:
             msg = " Failed to get pid for pidfile %s/%s " % (
                     home, pidfile )
@@ -395,30 +614,26 @@ class LinuxNode(ResourceManager):
 
     def wait_run(self, pid, ppid, trial = 0):
         """ wait for a remote process to finish execution """
-        delay = 1.0
-        first = True
-        bustspin = 0
+        start_delay = 1.0
 
         while True:
             status = self.status(pid, ppid)
             
-            if status is sshfuncs.FINISHED:
+            if status is ProcStatus.FINISHED:
                 break
-            elif status is not sshfuncs.RUNNING:
-                bustspin += 1
-                time.sleep(delay*(5.5+random.random()))
-                if bustspin > 12:
+            elif status is not ProcStatus.RUNNING:
+                delay = delay * 1.5
+                time.sleep(delay)
+                # If it takes more than 20 seconds to start, then
+                # asume something went wrong
+                if delay > 20:
                     break
             else:
-                if first:
-                    first = False
-
-                time.sleep(delay*(0.5+random.random()))
-                delay = min(30,delay*1.2)
-                bustspin = 0
+                # The app is running, just wait...
+                time.sleep(0.5)
 
     def check_output(self, home, filename):
-        """ checks file content """
+        """ Retrives content of file """
         (out, err), proc = self.execute("cat %s" % 
             os.path.join(home, filename), retry = 1, with_lock = True)
         return (out, err), proc
@@ -448,7 +663,7 @@ class LinuxNode(ResourceManager):
 
     def copy(self, src, dst):
         if self.localhost:
-            (out, err), proc =  execfuncs.lcopy(source, dest, 
+            (out, err), proc = execfuncs.lcopy(source, dest, 
                     recursive = True,
                     strict_host_checking = False)
         else:
@@ -475,6 +690,7 @@ class LinuxNode(ResourceManager):
             connect_timeout = 30,
             strict_host_checking = False,
             persistent = True,
+            blocking = True,
             with_lock = False
             ):
         """ Notice that this invocation will block until the
@@ -508,6 +724,7 @@ class LinuxNode(ResourceManager):
                         err_on_timeout = err_on_timeout,
                         connect_timeout = connect_timeout,
                         persistent = persistent,
+                        blocking = blocking, 
                         strict_host_checking = strict_host_checking
                         )
             else:
@@ -528,21 +745,22 @@ class LinuxNode(ResourceManager):
                     retry = retry,
                     err_on_timeout = err_on_timeout,
                     connect_timeout = connect_timeout,
-                    persistent = persistent
+                    persistent = persistent,
+                    blocking = blocking, 
+                    strict_host_checking = strict_host_checking
                     )
 
         return (out, err), proc
 
-    def run(self, command, 
-            home = None,
+    def run(self, command, home,
             create_home = False,
-            pidfile = "pid",
+            pidfile = 'pidfile',
             stdin = None, 
             stdout = 'stdout', 
             stderr = 'stderr', 
             sudo = False,
             tty = False):
-
+        
         self.debug("Running command '%s'" % command)
         
         if self.localhost:
@@ -555,10 +773,8 @@ class LinuxNode(ResourceManager):
                     sudo = sudo,
                     user = user) 
         else:
-            # Start process in a "daemonized" way, using nohup and heavy
-            # stdin/out redirection to avoid connection issues
             with self._lock:
-                (out,err), proc = sshfuncs.rspawn(
+                (out, err), proc = sshfuncs.rspawn(
                     command,
                     pidfile = pidfile,
                     home = home,
@@ -578,12 +794,12 @@ class LinuxNode(ResourceManager):
 
         return (out, err), proc
 
-    def checkpid(self, home = ".", pidfile = "pid"):
+    def getpid(self, home, pidfile = "pidfile"):
         if self.localhost:
-            pidtuple =  execfuncs.lcheckpid(os.path.join(home, pidfile))
+            pidtuple =  execfuncs.lgetpid(os.path.join(home, pidfile))
         else:
             with self._lock:
-                pidtuple = sshfuncs.rcheckpid(
+                pidtuple = sshfuncs.rgetpid(
                     os.path.join(home, pidfile),
                     host = self.get("hostname"),
                     user = self.get("username"),
@@ -594,7 +810,7 @@ class LinuxNode(ResourceManager):
                     )
         
         return pidtuple
-    
+
     def status(self, pid, ppid):
         if self.localhost:
             status = execfuncs.lstatus(pid, ppid)
@@ -617,7 +833,7 @@ class LinuxNode(ResourceManager):
         proc = None
         status = self.status(pid, ppid)
 
-        if status == sshfuncs.RUNNING:
+        if status == sshfuncs.ProcStatus.RUNNING:
             if self.localhost:
                 (out, err), proc = execfuncs.lkill(pid, ppid, sudo)
             else:
@@ -632,12 +848,6 @@ class LinuxNode(ResourceManager):
                         identity = self.get("identity"),
                         server_key = self.get("serverKey")
                         )
-        return (out, err), proc
 
-    def check_bad_host(self, out, err):
-        badre = re.compile(r'(?:'
-                           r'|Error: disk I/O error'
-                           r')', 
-                           re.I)
-        return badre.search(out) or badre.search(err)
+        return (out, err), proc