dockerrun.py

#!/usr/bin/python

__author__ = 'Fabrice Bacchella'

import optparse
import docker as dockerlib
import dockerpty
import yaml
try:
    from yaml import CLoader as Loader, CDumper as Dumper
except ImportError:
    from yaml import Loader, Dumper
import inspect
import tempfile
import os
import sys
import stat
import string
import collections
from pwd import getpwnam
import re
import socket
import traceback

class Verb(object):
    verbs = {}

    def __init__(self, name, numargs=0):
        self.name = name
        self.numargs = numargs

    def __call__(self, f):
        Verb.verbs[self.name] = (f, self.numargs)
        return f


# a template that allows . in variables name
class DotTemplate(string.Template):
    pattern = r"""
    \$(?:
      {(?P<braced>[_a-z][_a-z0-9\.]*)}     |   # delimiter and a braced identifier
      (?P<escaped>^$)                      |   # Escape sequence of two delimiters
      (?P<named>^$)                        |   # delimiter and a Python identifier
      (?P<invalid>^$)                          # Other ill-formed delimiter exprs
    )
    """


# A dictionary that resolve string using a template and variables
class TemplateDict(dict):

    def __init__(self, variables, *args, **kwargs):
        self.variables = variables
        super(TemplateDict, self).__init__(*args, **kwargs)

    def __getitem__(self, *args, **kwargs):
        value = super(TemplateDict, self).__getitem__(*args, **kwargs)
        return self.resolve(value)

    def items(self, *args, **kwargs):
        for (key, value) in super(TemplateDict, self).items(*args, **kwargs):
            yield (key, self.resolve(value))

    def pop(self, *args, **kwargs):
        value = super(TemplateDict, self).pop(*args, **kwargs)
        return self.resolve(value)

    def resolve(self, value):
        if isinstance(value, str):
            try:
                return DotTemplate(value).substitute(self.variables)
            except KeyError as e:
                print "undefined key '%s' at %s" %(e.args[0], value)
                return value
        elif isinstance(value, (list, tuple)):
            return map(lambda x: self.resolve(x), value)
        elif isinstance(value, dict):
            return dict(map(lambda (x, y): (x, self.resolve(y)), value.items()))
        else:
            return value

    def getraw(self, key):
        return super(TemplateDict, self).__getitem__(key)


class DockerOption(optparse.Option):
    ACTIONS = optparse.Option.ACTIONS + ("store_first", "store_variable", )
    STORE_ACTIONS = optparse.Option.STORE_ACTIONS + ("store_first", "store_variable", )
    TYPED_ACTIONS = optparse.Option.TYPED_ACTIONS + ("store_first", "store_variable", )
    ALWAYS_TYPED_ACTIONS = optparse.Option.ALWAYS_TYPED_ACTIONS + ("store_first", "store_variable", )

    def __init__(self, *args, **kwargs):
        if kwargs['action'] == "store_variable":
            kwargs['nargs'] = 2
            if not 'default' in kwargs:
                kwargs['default'] = {}
        elif kwargs['action'] == "store_first":
            self.seen = set([])
        optparse.Option.__init__(self, *args, **kwargs)

    def take_action(self, action, dest, opt, value, values, parser):
        if action == "store_first" and dest in self.seen:
            pass
        elif action == "store_variable":
            (v_key, v_value) = value
            values.variables[v_key] = v_value
        else:
            if action == "store_first":
                self.seen.add(dest)
                action = "store"
            optparse.Option.take_action(self, action, dest, opt, value, values, parser)


def check_contenair_user(info, user):
    for i in info['Config']['Env']:
        sep = i.index("=")
        (var,value) = (i[:sep], i[sep+1:])
        if var == 'CONTAINER_CREATOR':
            if value == user:
                return True
        return False
    return False


@Verb('run', 1)
def run(docker, path, variables, yamls):
    """run a new container, using a predefined yaml"""
    allowed_paths = []
    if path is not None:
        for element in path.split(os.pathsep):
            allowed_paths.append(os.path.normcase(os.path.abspath(element)))

    for docker_file_name in yamls:

        # Check if the docker yaml file is in an allowed path
        if len(allowed_paths) > 0:
            # no path given, look in allowed path and use it as the file name
            # path is checked any way, to resolve symbolic links
            if os.path.basename(docker_file_name) == docker_file_name:
                for element in allowed_paths:
                    if os.path.exists(element + os.sep + docker_file_name):
                        # use that as the new file name
                        docker_file_name = element + os.sep + docker_file_name
                        break
            # Resolve to a absolute real path
            # symbolic links are resolve too
            real_file_name = os.path.normcase(os.path.realpath(docker_file_name))
            valid = False
            for element in allowed_paths:
                if os.path.commonprefix([element, real_file_name]) == element:
                    valid = True
            if not valid:
                print >> sys.stderr, "invalid yaml container: %s" % docker_file_name
                return 1

        # Load the yaml docker file
        with open(docker_file_name, 'r') as docker_file:
            try:
                docker_conf = yaml.safe_load(docker_file)
            except (yaml.scanner.ScannerError, yaml.parser.ParserError) as e:
                print >> sys.stderr,  e
                return 1


        # Match variables against the filters
        for (key, value) in docker_conf.pop('check', {}).items():
            if key not in variables:
                print >> sys.stderr,  "undefined variable '%s'" % key
                return 1
            #The variable check is a string, the filter is a regex
            if type(value) == str or type(value) == unicode:
                if re.match("^" + value + "$", variables[key]) is None:
                    print >> sys.stderr,  "variable %s not a valid value: '%s'" % (key, variables[key])
                    return 1
            # it's a list, search in allowed values
            elif type(value) == list:
                if not variables[key] in value:
                    print >> sys.stderr,  "variable %s not an allowed value" % key
                    return 1

        # resolve variables expression
        for (var, expression) in docker_conf.pop('variables', {}).items():
            try:
                variables[var] = eval(expression, {}, variables)
            except Exception as e:
                print >> sys.stderr, "evaluation failed for %s:" % (expression)
                for l in traceback.format_exception_only(type(e), e):
                    print "    " + l,
                    return 1

        docker_kwargs = TemplateDict(variables, docker_conf)

        effective_create_kwargs = {}
        effective_start_kwargs = {}
        effective_hostconfig_kwargs = {}

        # Converted the binding, must be given as an array of single-element hash
        # transformed to OrderedDict, docker-py expect a dict
        if 'binds' in docker_kwargs:
            binds = docker_kwargs['binds']
            if not isinstance(binds, list):
                print >> sys.stderr,  "binding must be an array"
                return 1
            new_binds = collections.OrderedDict()
            for bind in binds:
                (key, value) = bind.items()[0]
                # now inverse the source and destination
                # the docker api is incoherent between port bind and mount bind
                source_binding = value.pop('bind', key)
                value['bind'] = key
                new_binds[source_binding] = value
            docker_kwargs['binds'] = new_binds

        # if a script is given, save it as a temporary file
        if 'script' in docker_kwargs:
            script = docker_kwargs.pop('script')
            with tempfile.NamedTemporaryFile(delete=False) as script_file:
                script_file.write(script)
                script_file.flush()
                os.chmod(script_file.name,
                         (stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO) & ~stat.S_IWUSR & ~stat.S_IWGRP & ~stat.S_IWOTH)
                docker_kwargs['command'] = [script_file.name]
            if 'binds' not in docker_kwargs:
                docker_kwargs['binds'] = collections.OrderedDict()
            docker_kwargs['binds'][script_file.name] = {'bind': script_file.name, 'ro': True}

        do_attach = not docker_kwargs.pop('detach', False)
        docker_kwargs['tty'] = do_attach
        docker_kwargs['stdin_open'] = do_attach

        do_rm = docker_kwargs.pop('rm', False)

        # list of capability to drop or add
        if 'cap_drop' in docker_kwargs and isinstance(docker_kwargs['cap_drop'], list):
            effective_start_kwargs['cap_drop'] = docker_kwargs.pop('cap_drop')
        if 'cap_add' in docker_kwargs and isinstance(docker_kwargs['cap_drop'], list):
            effective_start_kwargs['cap_add'] = docker_kwargs.pop('cap_add')

        # some exceptions, given in create_container, should be used in start:
        if 'volumes_from' in docker_kwargs:
            effective_hostconfig_kwargs['volumes_from'] = docker_kwargs.pop('volumes_from')
        if 'dns' in docker_kwargs:
            effective_hostconfig_kwargs['dns'] = docker_kwargs.pop('dns')

        # needs to manage port binding
        # it's dict of mapping
        # valid values for key is d+((-d+)|,d+)?(|tcp|udp)
        # valid values for destination is None, port, or a array of [host, port]
        # If a range was given, auto-increment destination
        if 'port_bindings' in docker_kwargs:
            effective_create_kwargs['ports'] = []
            port_bindings = {}
            for (port, port_definition) in docker_kwargs.pop('port_bindings').items():
                # If nothing, just a direct mapping
                if port_definition is None:
                    proto = "tcp"
                    listen_host = None
                    listen_ports = (port, )
                # if a plain integer, a one to one mapping
                elif type(port_definition) == int:
                    proto = "tcp"
                    listen_host = None
                    listen_ports = (port_definition, )
                else:
                    proto = port_definition.pop('protocol', 'tcp')
                    listen_host = port_definition.pop('host', None)
                    listen_range = port_definition.pop('range', None)
                    listen_ports = port_definition.pop('port', None)
                    if listen_ports is None and range is None:
                        listen_ports = (port, )
                    elif listen_ports is not None and listen_range is not None:
                        print >> sys.stderr, "port mapping %d given both range and port" % port
                        return 1
                    elif listen_ports is not None:
                        listen_ports = (listen_ports, )
                    elif listen_range is not None:
                        # we got a range
                        # it's  start,count
                        if listen_range.rfind(",") > 0:
                            listen_range = listen_range.split(",")
                            listen_ports = range(int(listen_range[0]), int(listen_range[0]) + int(listen_range[1]))
                        # or it start-stop
                        elif listen_range.rfind("-") > 0:
                            listen_range = listen_range.split("-")
                            listen_ports = range(int(listen_range[0]), int(listen_range[1]) + 1)
                    else:
                        print >> sys.stderr, "port mapping %d given neither range and port" % port
                        return 1
                for listen_port in listen_ports:
                    effective_create_kwargs['ports'].append((port, proto))
                    port_bindings["%d/%s" %(port, proto)] = (listen_host, listen_port)
                    port += 1

            effective_hostconfig_kwargs['port_bindings'] = port_bindings

        # Extract argument for hostconfig
        for arg_name in inspect.getargspec(dockerlib.utils.create_host_config).args:
            if arg_name in docker_kwargs:
                effective_hostconfig_kwargs[arg_name] = docker_kwargs.pop(arg_name)
        effective_create_kwargs['host_config'] = dockerlib.utils.create_host_config(**effective_hostconfig_kwargs)

        #start with 1, 0 is 'self'
        for arg_name in inspect.getargspec(dockerlib.Client.create_container).args[1:]:
            if arg_name in docker_kwargs:
                effective_create_kwargs[arg_name] = docker_kwargs.pop(arg_name)
        #start with 1, 0 is 'self'
        for arg_name in inspect.getargspec(dockerlib.Client.start).args[1:]:
            if arg_name in docker_kwargs:
                effective_start_kwargs[arg_name] = docker_kwargs.pop(arg_name)

        # don' forget to store the container creator
        if not 'environment' in effective_create_kwargs:
            effective_create_kwargs['environment'] = {}
        effective_create_kwargs['environment']['CONTAINER_CREATOR'] = variables['environment.SUDO_USER']

        # is a numeric id given for the user, or is it needed to resolve it ?
        if 'user' in effective_create_kwargs and not isinstance(effective_create_kwargs['user'], (int, long)):
            user = effective_create_kwargs['user']
            try:
                effective_create_kwargs['user'] = getpwnam(user).pw_uid
            except KeyError:
                print >> sys.stderr, "user '%s' not found" % user
                return 1

        if len(docker_kwargs) > 0:
            print >> sys.stderr, "invalid argument: %s" % docker_kwargs
            return 1

        container = docker.create_container(**effective_create_kwargs)
        if container['Warnings'] is not None:
            print >> sys.stderr, "warning: %s" % container.Warnings

        if do_attach:
            try:
                dockerpty.start(docker, container, **effective_start_kwargs)
                if do_rm:
                    docker.remove_container(container, v=True)
            except dockerlib.errors.APIError as e:
                print >> sys.stderr, e
            except socket.error:
                print >> sys.stderr, "container detached"
        else:
            docker.start(container, **effective_start_kwargs)

    return 0


@Verb('list')
def list_contenair(docker):
    """return the list of active contenaire"""
    real_user = os.environ['SUDO_USER']
    for container in docker.containers(all=True):
        info = docker.inspect_container(container)
        if check_contenair_user(info, real_user):
            print "%s %s %s" % (info['Name'][1:], info['Config']['Hostname'], container['Status'])
    return 0


@Verb('stop', numargs=1)
def stop(docker, container):
    """stop a container"""
    info = docker.inspect_container(container)
    real_user = os.environ['SUDO_USER']
    if check_contenair_user(info, real_user):
        docker.stop(container)
    else:
        print >> sys.stderr, "not you're own container"
    return 0


@Verb('start', numargs=1)
def start(docker, container):
    """start a container"""
    info = docker.inspect_container(container)
    real_user = os.environ['SUDO_USER']
    if check_contenair_user(info, real_user):
        os.execlp("docker", "docker", "start", container)
    else:
        print >> sys.stderr, "not you're own container"
    return 0


@Verb('rm', numargs=2)
def rm_contenair(docker, container, force=True):
    """remove a container, given is id or name"""
    info = docker.inspect_container(container)
    real_user = os.environ['SUDO_USER']
    if check_contenair_user(info, real_user):
        docker.remove_container(container, force=force)
    else:
        print >> sys.stderr, "not you're own container"
    return 0


@Verb('attach', numargs=1)
def attach(docker, container):
    """attach to a running container"""
    info = docker.inspect_container(container)
    real_user = os.environ['SUDO_USER']
    if check_contenair_user(info, real_user):
        os.execlp("docker", "docker", "attach", container)
    else:
        print >> sys.stderr, "not you're own container"
    return 0


@Verb('logs', numargs=1)
def logs(docker, container):
    """show the stdout and stderr logs from a container"""
    info = docker.inspect_container(container)
    real_user = os.environ['SUDO_USER']
    if check_contenair_user(info, real_user):
        print docker.logs(container, stdout=True, stderr=True, tail="all")
    else:
        print >> sys.stderr, "not you're own container"
    return 0


@Verb('tail', numargs=1)
def tail(docker, container):
    """follow stdout and stdin from a container, without attaching"""
    info = docker.inspect_container(container)
    real_user = os.environ['SUDO_USER']
    if check_contenair_user(info, real_user):
        for l in docker.logs(container, stream=True, stdout=True, stderr=True, tail=5):
            print l,
    else:
        print >> sys.stderr, "not you're own container"
    return 0


def main():
    help_header = "[args]* 'verb' [verb_args]*\n"
    for (verb, (function, numargs)) in Verb.verbs.items():
        if function.__doc__ is None:
            doc = ""
        else:
            doc = ": %s" % function.__doc__
        help_header += "%s%s\n" % (verb, doc)

    parser = optparse.OptionParser(option_class=DockerOption, usage=help_header)
    parser.add_option("-p", "--p", dest="path", help="allowed path for yaml files", default=None, action="store_first")
    parser.add_option("-u", "--url", dest="url", help="base URL for docker connection", default=None, action="store")
    parser.add_option("-s", "--socket", dest="socket", help="docker socket", default=None, action="store")
    parser.add_option("-a", "--api", dest="api_version", help="docker api version", default='1.18', action="store_first")
    parser.add_option("-t", "--timeout", dest="timeout", help="docker timeout", default=20, action="store", type="int")
    parser.add_option("-v", "--variable", dest="variables", action="store_variable", type="string")

    (options, args) = parser.parse_args()

    # Override -p with content of DOCKERRUN_YAMLPATH
    # it's used in sudoers
    if 'SUDO_COMMAND' in os.environ:
        # Check that SUDO_COMMAND was ourself
        # bash -s|-i also set SUDO_COMMAND
        run_command = os.path.basename(os.path.abspath(sys.argv[0]))
        sudo_command = os.path.basename(os.path.abspath(os.environ['SUDO_COMMAND'].split(' ')[0]))
        # argv is not the current file, not launched with sudo .../dockerrun
        # it's not our duty to check any more
        if run_command != sudo_command:
            pass
        elif 'DOCKERRUN_YAMLPATH' in os.environ:
            options.path = os.environ['DOCKERRUN_YAMLPATH']
        else:
            print >> sys.stderr, "run in sudo but not DOCKERRUN_YAMLPATH defined"
            return 1
    docker = dockerlib.Client(base_url=options.url,
                              version=options.api_version,
                              timeout=options.timeout)

    # add some values in the variables
    options.variables['system.uid'] = os.geteuid()
    for (name, value) in os.environ.items():
        options.variables['environment.%s' % name] = value

    if len(args) == 0:
        parser.print_help()
        return 1
    elif args[0] not in Verb.verbs:
        print >> sys.stderr, "unknow verb %s, allowed verbs are %s" % (args[0], Verb.verbs.keys())
    else:
        verb = args[0]
        if verb in Verb.verbs:
            (f, numargs) = Verb.verbs[verb]
            if len(args) < numargs:
                print >> sys.stderr, "not enough argument for %s" % verb
                if f.__doc__ is not None:
                    print f.__doc__
                return 1
            if verb == 'run':
                return f(docker, options.path, options.variables, *[args[1:]])
            else:
                return f(docker, *args[1:])

# no global name space pollution
if __name__ == "__main__":
    try:
        sys.exit(main())
    except KeyboardInterrupt:
        sys.exit(1)