From 80eb53deb9f80694c5fd0e0190197de1ff496716 Mon Sep 17 00:00:00 2001 From: Joshua Harlow Date: Wed, 10 Oct 2012 16:21:22 -0700 Subject: System config niceness! 1. Move out the old helpers that provided oop access/reading/writing to various standard conf files and place those in parsers instead. 2. Unify the 'update_hostname' which varied very little between distros and make it generic so that subclasses can only provide a couple of functions to obtain the hostname updating functionality 3. Implement that new set of functions in rhel/debian 4. Use the new parsers chop_comment function for similar use cases as well as add a new utils make header function that can be used for configuration files that are newly generated to use (less duplication here of this same thing being done in multiple places. 5. Add in a distro '_apply_hostname' which calls out to the 'hostname' program to set the system hostname (more duplication elimination). 6. Make the 'constant' filenames being written to for configuration by the various distros be instance members instead of string constants 'sprinkled' throughout the code --- cloudinit/distros/__init__.py | 89 +++++++++++++++++++++++++++++++++---------- 1 file changed, 68 insertions(+), 21 deletions(-) (limited to 'cloudinit/distros/__init__.py') diff --git a/cloudinit/distros/__init__.py b/cloudinit/distros/__init__.py index a5d41bdb..07f03159 100644 --- a/cloudinit/distros/__init__.py +++ b/cloudinit/distros/__init__.py @@ -33,7 +33,7 @@ from cloudinit import log as logging from cloudinit import ssh_util from cloudinit import util -from cloudinit.distros import helpers +from cloudinit.distros.parsers import hosts LOG = logging.getLogger(__name__) @@ -43,6 +43,8 @@ class Distro(object): __metaclass__ = abc.ABCMeta default_user = None default_user_groups = None + hosts_fn = "/etc/hosts" + ci_sudoers_fn = "/etc/sudoers.d/90-cloud-init-users" def __init__(self, name, cfg, paths): self._paths = paths @@ -66,10 +68,6 @@ class Distro(object): def set_hostname(self, hostname): raise NotImplementedError() - @abc.abstractmethod - def update_hostname(self, hostname, prev_hostname_fn): - raise NotImplementedError() - @abc.abstractmethod def package_command(self, cmd, args=None): raise NotImplementedError() @@ -117,14 +115,62 @@ class Distro(object): def _get_localhost_ip(self): return "127.0.0.1" + @abc.abstractmethod + def _read_hostname(self, filename, default=None): + raise NotImplementedError() + + @abc.abstractmethod + def _write_hostname(self, hostname, filename): + raise NotImplementedError() + + @abc.abstractmethod + def _read_system_hostname(self): + raise NotImplementedError() + + def _apply_hostname(self, hostname): + LOG.debug("Setting system hostname to %s", hostname) + util.subp(['hostname', hostname]) + + def update_hostname(self, hostname, prev_hostname_fn): + if not hostname: + return + + prev_hostname = self._read_hostname(prev_hostname_fn) + (sys_fn, sys_hostname) = self._read_system_hostname() + update_files = [] + if not prev_hostname or prev_hostname != hostname: + update_files.append(prev_hostname_fn) + + if (not sys_hostname) or (sys_hostname == prev_hostname + and sys_hostname != hostname): + update_files.append(sys_fn) + + update_files = set([f for f in update_files if f]) + LOG.debug("Attempting to update hostname to %s in %s files", + hostname, len(update_files)) + + for fn in update_files: + try: + self._write_hostname(hostname, fn) + except IOError: + util.logexc(LOG, "Failed to write hostname %s to %s", + hostname, fn) + + if (sys_hostname and prev_hostname and + sys_hostname != prev_hostname): + LOG.debug("%s differs from %s, assuming user maintained hostname.", + prev_hostname_fn, sys_fn) + + if sys_fn in update_files: + self._apply_hostname(hostname) + def update_etc_hosts(self, hostname, fqdn): header = '' - if os.path.exists('/etc/hosts'): - eh = helpers.HostsConf(util.load_file("/etc/hosts")) + if os.path.exists(self.hosts_fn): + eh = hosts.HostsConf(util.load_file(self.hosts_fn)) else: - eh = helpers.HostsConf('') - header = "# Added by cloud-init" - header = "%s on %s" % (header, util.time_rfc2822()) + eh = hosts.HostsConf('') + header = util.make_header(base="added") local_ip = self._get_localhost_ip() prev_info = eh.get_entry(local_ip) need_change = False @@ -154,7 +200,7 @@ class Distro(object): if header: contents.write("%s\n" % (header)) contents.write("%s\n" % (eh)) - util.write_file("/etc/hosts", contents.getvalue(), mode=0644) + util.write_file(self.hosts_fn, contents.getvalue(), mode=0644) def _bring_up_interface(self, device_name): cmd = ['ifup', device_name] @@ -302,30 +348,31 @@ class Distro(object): return True - def write_sudo_rules(self, - user, - rules, - sudo_file="/etc/sudoers.d/90-cloud-init-users", - ): + def write_sudo_rules(self, user, rules, sudo_file=None): + if not sudo_file: + sudo_file = self.ci_sudoers_fn - content_header = "# user rules for %s" % user + content_header = "# User rules for %s" % user content = "%s\n%s %s\n\n" % (content_header, user, rules) - if isinstance(rules, list): + if isinstance(rules, (list, tuple, set)): content = "%s\n" % content_header for rule in rules: content += "%s %s\n" % (user, rule) content += "\n" if not os.path.exists(sudo_file): - util.write_file(sudo_file, content, 0440) - + contents = [ + util.make_header(), + content, + ] + util.write_file(sudo_file, "\n".join(contents), 0440) else: try: with open(sudo_file, 'a') as f: f.write(content) except IOError as e: - util.logexc(LOG, "Failed to write %s" % sudo_file, e) + util.logexc(LOG, "Failed to write sudoers file %s", sudo_file) raise e def create_group(self, name, members): -- cgit v1.2.3