cloud-init/cloud-init.py

#!/usr/bin/python
# vi: ts=4 expandtab
#
#    Copyright (C) 2009-2010 Canonical Ltd.
#
#    Author: Scott Moser <scott.moser@canonical.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 3, as
#    published by the Free Software Foundation.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

import subprocess
import sys

import cloudinit
import cloudinit.util as util
import cloudinit.CloudConfig as CC
import cloudinit.DataSource as ds
import time
import logging
import errno
import os

def warn(wstr):
    sys.stderr.write("WARN:%s" % wstr)

def main():
    cmds = ( "start", "start-local" )
    deps = { "start" : ( ds.DEP_FILESYSTEM, ds.DEP_NETWORK ),
             "start-local" : ( ds.DEP_FILESYSTEM, ) }

    cmd = ""
    if len(sys.argv) > 1:
        cmd = sys.argv[1]

    cfg_path = None
    if len(sys.argv) > 2:
        # this is really for debugging only
        # but you can invoke on development system with ./config/cloud.cfg
        cfg_path = sys.argv[2]

    if not cmd in cmds:
        sys.stderr.write("bad command %s. use one of %s\n" % (cmd, cmds))
        sys.exit(1)

    now = time.strftime("%a, %d %b %Y %H:%M:%S %z",time.gmtime())
    try:
       uptimef=open("/proc/uptime")
       uptime=uptimef.read().split(" ")[0]
       uptimef.close()
    except IOError as e:
       warn("unable to open /proc/uptime\n")
       uptime = "na"

    try:
        cfg = cloudinit.get_base_cfg(cfg_path)
    except Exception as e:
        warn("Failed to get base config. falling back to builtin: %s\n" % e)
        try:
            cfg = cloudinit.get_builtin_cfg()
        except Exception as e:
            warn("Unable to load builtin config\n")
            raise

    try:
        (outfmt, errfmt) = CC.get_output_cfg(cfg,"init")
        CC.redirect_output(outfmt, errfmt)
    except Exception as e:
        warn("Failed to get and set output config: %s\n" % e)

    cloudinit.logging_set_from_cfg(cfg)
    log = logging.getLogger()

    try:
        cloudinit.initfs()
    except Exception as e:
        warn("failed to initfs, likely bad things to come: %s\n" % str(e))

    nonet_path = "%s/%s" % (cloudinit.get_cpath("data"), "no-net")

    if cmd == "start":
        stop_files = ( cloudinit.get_ipath_cur("obj_pkl"), nonet_path )
        # if starting as the network start, there are cases
        # where everything is already done for us, and it makes
        # most sense to exit early and silently
        for f in stop_files:
            try:
                fp = open("/var/lib/cloud/instance/obj.pkl","r")
                fp.close()
            except:
                continue
            
            log.debug("no need for cloud-init start to run (%s)\n", f)
            sys.exit(0)
    elif cmd == "start-local":
        # cache is not instance specific, so it has to be purged
        # but we want 'start' to benefit from a cache if
        # a previous start-local populated one
        manclean = util.get_cfg_option_bool(cfg, 'manual_cache_clean',False)
        if manclean:
            log.debug("not purging cache, manual_cache_clean = True")
        cloudinit.purge_cache(not manclean)

        try:
            os.unlink(nonet_path)
        except OSError as e:
            if e.errno != errno.ENOENT: raise

    msg = "cloud-init %s running: %s. up %s seconds" % (cmd, now, uptime)
    sys.stderr.write(msg + "\n")
    sys.stderr.flush()

    log.info(msg)

    cloud = cloudinit.CloudInit(ds_deps=deps[cmd])

    try:
        cloud.get_data_source()
    except cloudinit.DataSourceNotFoundException as e:
        sys.stderr.write("no instance data found in %s\n" % cmd)
        sys.exit(1)

    # set this as the current instance
    cloud.set_cur_instance()

    # store the metadata
    cloud.update_cache()

    msg = "found data source: %s" % cloud.datasource
    sys.stderr.write(msg + "\n")
    log.debug(msg)

    # parse the user data (ec2-run-userdata.py)
    try:
        cloud.sem_and_run("consume_userdata", "once-per-instance",
            cloud.consume_userdata,[],False)
    except:
        warn("consuming user data failed!\n")
        raise

    # finish, send the cloud-config event
    cloud.initctl_emit()

    cfg_path = cloudinit.get_ipath_cur("cloud_config")
    cc = CC.CloudConfig(cfg_path, cloud)

    # if the output config changed, update output and err
    try:
        outfmt_orig = outfmt
        errfmt_orig = errfmt
        (outfmt, errfmt) = CC.get_output_cfg(cc.cfg,"init")
        if outfmt_orig != outfmt or errfmt_orig != errfmt:
            warn("stdout, stderr changing to (%s,%s)" % (outfmt,errfmt))
            CC.redirect_output(outfmt, errfmt)
    except Exception as e:
        warn("Failed to get and set output config: %s\n" % e)

    module_list = CC.read_cc_modules(cc.cfg,"cloud_init_modules")

    failures = []
    if len(module_list):
        failures = CC.run_cc_modules(cc,module_list,log)
    else:
        msg = "no cloud_init_modules to run"
        sys.stderr.write(msg + "\n")
        log.debug(msg)
        sys.exit(0)

    sys.exit(len(failures))

if __name__ == '__main__':
    main()