diff options
| -rwxr-xr-x | cloud-init.py | 83 | ||||
| -rw-r--r-- | cloud.cfg | 1 |
2 files changed, 76 insertions, 8 deletions
diff --git a/cloud-init.py b/cloud-init.py index af09a66c..ff70017f 100755 --- a/cloud-init.py +++ b/cloud-init.py @@ -24,6 +24,7 @@ import cloudinit import cloudinit.util as util import time import logging +import errno def warn(str): sys.stderr.write(str) @@ -70,9 +71,14 @@ def main(): raise try: - hostname = cloud.get_hostname() - cloud.sem_and_run("set_hostname", "once-per-instance", - set_hostname, [ hostname ], False) + if util.get_cfg_option_bool(cloud.cfg,"preserve_hostname",False): + log.debug("preserve_hostname is set. not managing hostname") + else: + hostname = cloud.get_hostname() + cloud.sem_and_run("set_hostname", "once-per-instance", + set_hostname, [ hostname, log ], False) + cloud.sem_and_run("update_hostname", "always", + update_hostname, [ hostname, log ], False) except: warn("failed to set hostname\n") @@ -100,11 +106,72 @@ def apply_locale(locale): util.render_to_file('default-locale', '/etc/default/locale', \ { 'locale' : locale }) -def set_hostname(hostname): - subprocess.Popen(['hostname', hostname]).communicate() - f=open("/etc/hostname","wb") - f.write("%s\n" % hostname) - f.close() +# read hostname from a 'hostname' file +# allow for comments and stripping line endings. +# if file doesn't exist, or no contents, return default +def read_hostname(filename, default=None): + try: + fp = open(filename,"r") + lines = fp.readlines() + fp.close() + for line in lines: + hpos = line.find("#") + if hpos != -1: + line = line[0:hpos] + line = line.rstrip() + if line: + return line + except IOError, e: + if e.errno == errno.ENOENT: pass + return default + +def set_hostname(hostname, log): + try: + subprocess.Popen(['hostname', hostname]).communicate() + util.write_file("/etc/hostname","%s\n" % hostname, 0644) + log.debug("populated /etc/hostname with %s on first boot", hostname) + except: + log.error("failed to set_hostname") + +def update_hostname(hostname, log): + prev_file="%s/%s" % (cloudinit.datadir,"previous-hostname") + etc_file = "/etc/hostname" + + hostname_prev = None + hostname_in_etc = None + + try: + hostname_prev = read_hostname(prev_file) + except: + log.warn("Failed to open %s" % prev_file) + + try: + hostname_in_etc = read_hostname(etc_file) + except: + log.warn("Failed to open %s" % etc_file) + + update_files = [] + if not hostname_prev or hostname_prev != hostname: + update_files.append(prev_file) + + if (not hostname_in_etc or + (hostname_in_etc == hostname_prev and hostname_in_etc != hostname)): + update_files.append(etc_file) + + try: + for fname in update_files: + util.write_file(fname,"%s\n" % hostname, 0644) + log.debug("wrote %s to %s" % (hostname,fname)) + except: + log.warn("failed to write hostname to %s" % fname) + + if hostname_in_etc and hostname_prev and hostname_in_etc != hostname_prev: + log.debug("%s differs from %s. assuming user maintained" % + (prev_file,etc_file)) + + if etc_file in update_files: + log.debug("setting hostname to %s" % hostname) + subprocess.Popen(['hostname', hostname]).communicate() if __name__ == '__main__': main() @@ -1,3 +1,4 @@ cloud_type: auto user: ubuntu disable_root: 1 +preserve_hostname: False |