diff options
Diffstat (limited to 'cloudinit/net/dhcp.py')
| -rw-r--r-- | cloudinit/net/dhcp.py | 50 |
1 files changed, 33 insertions, 17 deletions
diff --git a/cloudinit/net/dhcp.py b/cloudinit/net/dhcp.py index 19d0199c..4394c68b 100644 --- a/cloudinit/net/dhcp.py +++ b/cloudinit/net/dhcp.py @@ -17,6 +17,7 @@ from cloudinit.net import ( has_url_connectivity) from cloudinit.net.network_state import mask_and_ipv4_to_bcast_addr as bcip from cloudinit import temp_utils +from cloudinit import subp from cloudinit import util LOG = logging.getLogger(__name__) @@ -30,19 +31,18 @@ class InvalidDHCPLeaseFileError(Exception): Current uses are DataSourceAzure and DataSourceEc2 during ephemeral boot to scrape metadata. """ - pass class NoDHCPLeaseError(Exception): """Raised when unable to get a DHCP lease.""" - pass class EphemeralDHCPv4(object): - def __init__(self, iface=None, connectivity_url=None): + def __init__(self, iface=None, connectivity_url=None, dhcp_log_func=None): self.iface = iface self._ephipv4 = None self.lease = None + self.dhcp_log_func = dhcp_log_func self.connectivity_url = connectivity_url def __enter__(self): @@ -80,9 +80,10 @@ class EphemeralDHCPv4(object): if self.lease: return self.lease try: - leases = maybe_perform_dhcp_discovery(self.iface) - except InvalidDHCPLeaseFileError: - raise NoDHCPLeaseError() + leases = maybe_perform_dhcp_discovery( + self.iface, self.dhcp_log_func) + except InvalidDHCPLeaseFileError as e: + raise NoDHCPLeaseError() from e if not leases: raise NoDHCPLeaseError() self.lease = leases[-1] @@ -130,13 +131,15 @@ class EphemeralDHCPv4(object): result[internal_mapping] = self.lease.get(different_names) -def maybe_perform_dhcp_discovery(nic=None): +def maybe_perform_dhcp_discovery(nic=None, dhcp_log_func=None): """Perform dhcp discovery if nic valid and dhclient command exists. If the nic is invalid or undiscoverable or dhclient command is not found, skip dhcp_discovery and return an empty dict. @param nic: Name of the network interface we want to run dhclient on. + @param dhcp_log_func: A callable accepting the dhclient output and error + streams. @return: A list of dicts representing dhcp options for each lease obtained from the dhclient discovery if run, otherwise an empty list is returned. @@ -150,7 +153,7 @@ def maybe_perform_dhcp_discovery(nic=None): LOG.debug( 'Skip dhcp_discovery: nic %s not found in get_devicelist.', nic) return [] - dhclient_path = util.which('dhclient') + dhclient_path = subp.which('dhclient') if not dhclient_path: LOG.debug('Skip dhclient configuration: No dhclient command found.') return [] @@ -158,7 +161,7 @@ def maybe_perform_dhcp_discovery(nic=None): prefix='cloud-init-dhcp-', needs_exe=True) as tdir: # Use /var/tmp because /run/cloud-init/tmp is mounted noexec - return dhcp_discovery(dhclient_path, nic, tdir) + return dhcp_discovery(dhclient_path, nic, tdir, dhcp_log_func) def parse_dhcp_lease_file(lease_file): @@ -192,13 +195,15 @@ def parse_dhcp_lease_file(lease_file): return dhcp_leases -def dhcp_discovery(dhclient_cmd_path, interface, cleandir): +def dhcp_discovery(dhclient_cmd_path, interface, cleandir, dhcp_log_func=None): """Run dhclient on the interface without scripts or filesystem artifacts. @param dhclient_cmd_path: Full path to the dhclient used. @param interface: Name of the network inteface on which to dhclient. @param cleandir: The directory from which to run dhclient as well as store dhcp leases. + @param dhcp_log_func: A callable accepting the dhclient output and error + streams. @return: A list of dicts of representing the dhcp leases parsed from the dhcp.leases file or empty list. @@ -215,14 +220,20 @@ def dhcp_discovery(dhclient_cmd_path, interface, cleandir): pid_file = os.path.join(cleandir, 'dhclient.pid') lease_file = os.path.join(cleandir, 'dhcp.leases') + # In some cases files in /var/tmp may not be executable, launching dhclient + # from there will certainly raise 'Permission denied' error. Try launching + # the original dhclient instead. + if not os.access(sandbox_dhclient_cmd, os.X_OK): + sandbox_dhclient_cmd = dhclient_cmd_path + # ISC dhclient needs the interface up to send initial discovery packets. # Generally dhclient relies on dhclient-script PREINIT action to bring the # link up before attempting discovery. Since we are using -sf /bin/true, # we need to do that "link up" ourselves first. - util.subp(['ip', 'link', 'set', 'dev', interface, 'up'], capture=True) + subp.subp(['ip', 'link', 'set', 'dev', interface, 'up'], capture=True) cmd = [sandbox_dhclient_cmd, '-1', '-v', '-lf', lease_file, '-pf', pid_file, interface, '-sf', '/bin/true'] - util.subp(cmd, capture=True) + out, err = subp.subp(cmd, capture=True) # Wait for pid file and lease file to appear, and for the process # named by the pid file to daemonize (have pid 1 as its parent). If we @@ -239,6 +250,7 @@ def dhcp_discovery(dhclient_cmd_path, interface, cleandir): return [] ppid = 'unknown' + daemonized = False for _ in range(0, 1000): pid_content = util.load_file(pid_file).strip() try: @@ -250,13 +262,17 @@ def dhcp_discovery(dhclient_cmd_path, interface, cleandir): if ppid == 1: LOG.debug('killing dhclient with pid=%s', pid) os.kill(pid, signal.SIGKILL) - return parse_dhcp_lease_file(lease_file) + daemonized = True + break time.sleep(0.01) - LOG.error( - 'dhclient(pid=%s, parentpid=%s) failed to daemonize after %s seconds', - pid_content, ppid, 0.01 * 1000 - ) + if not daemonized: + LOG.error( + 'dhclient(pid=%s, parentpid=%s) failed to daemonize after %s ' + 'seconds', pid_content, ppid, 0.01 * 1000 + ) + if dhcp_log_func is not None: + dhcp_log_func(out, err) return parse_dhcp_lease_file(lease_file) |