tahoe-lafs/src/allmydata/scripts/startstop_node.py

import os, sys, signal, time, subprocess
from twisted.python import usage
from allmydata.scripts.common import BasedirMixin
from allmydata.util import fileutil
from twisted.python.procutils import which

class StartOptions(BasedirMixin, usage.Options):
    optParameters = [
        ["basedir", "C", None, "which directory to start the node in"],
        ]

class StopOptions(BasedirMixin, usage.Options):
    optParameters = [
        ["basedir", "C", None, "which directory to stop the node in"],
        ]

class RestartOptions(BasedirMixin, usage.Options):
    optParameters = [
        ["basedir", "C", None, "which directory to restart the node in"],
        ]
    optFlags = [
        ["force", "f", "if the node is not already running, start it "
         "instead of complaining that you should have used 'start' instead "
         "of 'restart'"],
        ]


def testtwistd(loc):
    try:
        return subprocess.call(["python", loc,], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    except:
        return -1

def find_twistd():
    for maybetwistd in which("twistd"):
        ret = testtwistd(maybetwistd)
        if ret == 0:
            return maybetwistd

    for maybetwistd in which("twistd.py"):
        ret = testtwistd(maybetwistd)
        if ret == 0:
            return maybetwistd

    maybetwistd = os.path.join(sys.prefix, 'Scripts', 'twistd')
    ret = testtwistd(maybetwistd)
    if ret == 0:
        return maybetwistd

    maybetwistd = os.path.join(sys.prefix, 'Scripts', 'twistd.py')
    ret = testtwistd(maybetwistd)
    if ret == 0:
        return maybetwistd

    print "Can't find twistd (it comes with Twisted).  Aborting."
    sys.exit(1)


def do_start(basedir, config, out=sys.stdout, err=sys.stderr):
    print >>out, "STARTING", basedir
    if os.path.exists(os.path.join(basedir, "client.tac")):
        tac = "client.tac"
        type = "client"
    elif os.path.exists(os.path.join(basedir, "introducer.tac")):
        tac = "introducer.tac"
        type = "introducer"
    else:
        print >>err, "%s does not look like a node directory" % basedir
        if not os.path.isdir(basedir):
            print >>err, " in fact, it doesn't look like a directory at all!"
        sys.exit(1)
    twistd = find_twistd()
    fileutil.make_dirs(os.path.join(basedir, "logs"))
    cmd = ["python", twistd, "-y", tac, "--logfile", "logs/twistd.log"]
    rc = subprocess.call(cmd, cwd=basedir)
    if rc == 0:
        print >>out, "%s node probably started" % type
        return 0
    else:
        print >>err, "%s node probably not started" % type
        return 1

def do_stop(basedir, config, out=sys.stdout, err=sys.stderr):
    print >>out, "STOPPING", basedir
    pidfile = os.path.join(basedir, "twistd.pid")
    if not os.path.exists(pidfile):
        print >>err, "%s does not look like a running node directory (no twistd.pid)" % basedir
        return 2
    pid = open(pidfile, "r").read()
    pid = int(pid)

    timer = 0
    try:
        os.kill(pid, signal.SIGTERM)
    except OSError, oserr:
        if oserr.errno == 3:
            print oserr.strerror
            return 1
        else:
            raise
    time.sleep(0.1)
    while timer < 5:
        # poll once per second until twistd.pid goes away, up to 5 seconds
        try:
            os.kill(pid, 0)
        except OSError:
            print >>out, "process %d is dead" % pid
            return
        timer += 1
        time.sleep(1)
    print >>err, "never saw process go away"
    return 1

def start(config, stdout, stderr):
    rc = 0
    for basedir in config['basedirs']:
        rc = do_start(basedir, config, stdout, stderr) or rc
    return rc

def stop(config, stdout, stderr):
    rc = 0
    for basedir in config['basedirs']:
        rc = do_stop(basedir, config, stdout, stderr) or rc
    return rc

def restart(config, stdout, stderr):
    rc = 0
    for basedir in config['basedirs']:
        rc = do_stop(basedir, config, stdout, stderr) or rc
    if rc == 2 and config['force']:
        print >>stderr, "ignoring couldn't-stop"
        rc = 0
    if rc:
        print >>stderr, "not restarting"
        return rc
    for basedir in config['basedirs']:
        rc = do_start(basedir, config, stdout, stderr) or rc
    return rc


subCommands = [
    ["start", None, StartOptions, "Start a node (of any type)."],
    ["stop", None, StopOptions, "Stop a node."],
    ["restart", None, RestartOptions, "Restart a node."],
]

dispatch = {
    "start": start,
    "stop": stop,
    "restart": restart,
    }